Add Google tool calling

Add Vertex AI support
Add Anthropic tool calling support
2026-03-02 17:12:15 +00:00 · 2026-03-02 16:52:57 +00:00 · 2026-03-02 16:08:39 +00:00 · 2026-03-02 16:06:38 +00:00 · 2026-03-02 15:55:03 +00:00 · 2026-03-02 15:36:56 +00:00
28 changed files with 2662 additions and 297 deletions
--- a/.gitignore
+++ b/.gitignore
@@ -53,3 +53,6 @@ logs/

 # Python scripts
 __pycache__/*
+
+# Node.js (compliance tests)
+tests/node_modules/
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-# Go LLM Gateway
+# latticelm

 ## Overview

@@ -11,6 +11,7 @@ Simplify LLM integration by exposing a single, consistent API that routes reques
 - **Azure OpenAI** (Azure-deployed models)
 - **Anthropic** (Claude)
 - **Google Generative AI** (Gemini)
+- **Vertex AI** (Google Cloud-hosted Gemini models)

 Instead of managing multiple SDK integrations in your application, call one endpoint and let the gateway handle provider-specific implementations.

@@ -19,12 +20,13 @@ Instead of managing multiple SDK integrations in your application, call one endp
 ```
 Client Request
    ↓
-Go LLM Gateway (unified API)
+latticelm (unified API)
    ↓
 ├─→ OpenAI SDK
 ├─→ Azure OpenAI (OpenAI SDK + Azure auth)
 ├─→ Anthropic SDK
-└─→ Google Gen AI SDK
+├─→ Google Gen AI SDK
+└─→ Vertex AI (Google Gen AI SDK + GCP auth)
 ```

 ## Key Features
@@ -45,11 +47,12 @@ Go LLM Gateway (unified API)

 ## 🎉 Status: **WORKING!**

-✅ **All four providers integrated with official Go SDKs:**
- OpenAI → `github.com/openai/openai-go`
- Azure OpenAI → `github.com/openai/openai-go` (with Azure auth)
+✅ **All providers integrated with official Go SDKs:**
+- OpenAI → `github.com/openai/openai-go/v3`
+- Azure OpenAI → `github.com/openai/openai-go/v3` (with Azure auth)
 - Anthropic → `github.com/anthropics/anthropic-sdk-go`
 - Google → `google.golang.org/genai`
+- Vertex AI → `google.golang.org/genai` (with GCP auth)

 ✅ **Compiles successfully** (36MB binary)
 ✅ **Provider auto-selection** (gpt→Azure/OpenAI, claude→Anthropic, gemini→Google)
@@ -68,7 +71,7 @@ export ANTHROPIC_API_KEY="your-key"
 export GOOGLE_API_KEY="your-key"

 # 2. Build
-cd go-llm-gateway
+cd latticelm
 go build -o gateway ./cmd/gateway

 # 3. Run
--- a/cmd/gateway/main.go
+++ b/cmd/gateway/main.go
@@ -1,6 +1,7 @@
 package main

 import (
+	"context"
 	"database/sql"
 	"flag"
 	"fmt"
@@ -12,12 +13,13 @@ import (
 	_ "github.com/go-sql-driver/mysql"
 	_ "github.com/jackc/pgx/v5/stdlib"
 	_ "github.com/mattn/go-sqlite3"
+	"github.com/redis/go-redis/v9"

-	"github.com/yourusername/go-llm-gateway/internal/auth"
-	"github.com/yourusername/go-llm-gateway/internal/config"
-	"github.com/yourusername/go-llm-gateway/internal/conversation"
-	"github.com/yourusername/go-llm-gateway/internal/providers"
-	"github.com/yourusername/go-llm-gateway/internal/server"
+	"github.com/ajac-zero/latticelm/internal/auth"
+	"github.com/ajac-zero/latticelm/internal/config"
+	"github.com/ajac-zero/latticelm/internal/conversation"
+	"github.com/ajac-zero/latticelm/internal/providers"
+	"github.com/ajac-zero/latticelm/internal/server"
 )

 func main() {
@@ -112,6 +114,22 @@ func initConversationStore(cfg config.ConversationConfig, logger *log.Logger) (c
 		}
 		logger.Printf("Conversation store initialized (sql/%s, TTL: %s)", driver, ttl)
 		return store, nil
+	case "redis":
+		opts, err := redis.ParseURL(cfg.DSN)
+		if err != nil {
+			return nil, fmt.Errorf("parse redis dsn: %w", err)
+		}
+		client := redis.NewClient(opts)
+
+		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
+
+		if err := client.Ping(ctx).Err(); err != nil {
+			return nil, fmt.Errorf("connect to redis: %w", err)
+		}
+
+		logger.Printf("Conversation store initialized (redis, TTL: %s)", ttl)
+		return conversation.NewRedisStore(client, ttl), nil
 	default:
 		logger.Printf("Conversation store initialized (memory, TTL: %s)", ttl)
 		return conversation.NewMemoryStore(ttl), nil
--- a/config.example.yaml
+++ b/config.example.yaml
@@ -14,6 +14,12 @@ providers:
    type: "openai"
    api_key: "YOUR_OPENAI_API_KEY"
    endpoint: "https://api.openai.com"
+  # Vertex AI (Google Cloud) - optional
+  # Uses Application Default Credentials (ADC) or service account
+  # vertexai:
+  #   type: "vertexai"
+  #   project: "your-gcp-project-id"
+  #   location: "us-central1"  # or other GCP region
  # Azure OpenAI - optional
  # azureopenai:
  #   type: "azureopenai"
@@ -27,16 +33,19 @@ providers:
  #   endpoint: "https://your-resource.services.ai.azure.com/anthropic"

 # conversations:
-#   store: "sql"        # "memory" (default) or "sql"
+#   store: "sql"        # "memory" (default), "sql", or "redis"
 #   ttl: "1h"           # conversation expiration (default: 1h)
-#   driver: "sqlite3"   # SQL driver: "sqlite3", "mysql", "pgx"
-#   dsn: "conversations.db"  # connection string
+#   driver: "sqlite3"   # SQL driver: "sqlite3", "mysql", "pgx" (required for sql store)
+#   dsn: "conversations.db"  # connection string (required for sql/redis store)
 #   # MySQL example:
 #   # driver: "mysql"
 #   # dsn: "user:password@tcp(localhost:3306)/dbname?parseTime=true"
 #   # PostgreSQL example:
 #   # driver: "pgx"
 #   # dsn: "postgres://user:password@localhost:5432/dbname?sslmode=disable"
+#   # Redis example:
+#   # store: "redis"
+#   # dsn: "redis://:password@localhost:6379/0"

 models:
  - name: "gemini-1.5-flash"
@@ -45,6 +54,8 @@ models:
    provider: "anthropic"
  - name: "gpt-4o-mini"
    provider: "openai"
+  # - name: "gemini-2.0-flash-exp"
+  #   provider: "vertexai"  # Use Vertex AI instead of Google AI API
  # - name: "gpt-4o"
  #   provider: "azureopenai"
  #   provider_model_id: "my-gpt4o-deployment"  # optional: defaults to name
--- a/go.mod
+++ b/go.mod
@@ -1,11 +1,17 @@
-module github.com/yourusername/go-llm-gateway
+module github.com/ajac-zero/latticelm

 go 1.25.7

 require (
 	github.com/anthropics/anthropic-sdk-go v1.26.0
+	github.com/go-sql-driver/mysql v1.9.3
+	github.com/golang-jwt/jwt/v5 v5.3.1
 	github.com/google/uuid v1.6.0
+	github.com/jackc/pgx/v5 v5.8.0
+	github.com/mattn/go-sqlite3 v1.14.34
 	github.com/openai/openai-go v1.12.0
+	github.com/openai/openai-go/v3 v3.2.0
+	github.com/redis/go-redis/v9 v9.18.0
 	google.golang.org/genai v1.48.0
 	gopkg.in/yaml.v3 v3.0.1
 )
@@ -15,11 +21,10 @@ require (
 	cloud.google.com/go/auth v0.9.3 // indirect
 	cloud.google.com/go/compute/metadata v0.5.0 // indirect
 	filippo.io/edwards25519 v1.1.0 // indirect
-	github.com/Azure/azure-sdk-for-go/sdk/ai/azopenai v0.9.0 // indirect
 	github.com/Azure/azure-sdk-for-go/sdk/azcore v1.21.0 // indirect
 	github.com/Azure/azure-sdk-for-go/sdk/internal v1.11.2 // indirect
-	github.com/go-sql-driver/mysql v1.9.3 // indirect
-	github.com/golang-jwt/jwt/v5 v5.3.1 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
 	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
 	github.com/google/go-cmp v0.6.0 // indirect
 	github.com/google/s2a-go v0.1.8 // indirect
@@ -27,15 +32,13 @@ require (
 	github.com/gorilla/websocket v1.5.3 // indirect
 	github.com/jackc/pgpassfile v1.0.0 // indirect
 	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
-	github.com/jackc/pgx/v5 v5.8.0 // indirect
 	github.com/jackc/puddle/v2 v2.2.2 // indirect
-	github.com/mattn/go-sqlite3 v1.14.34 // indirect
-	github.com/openai/openai-go/v3 v3.2.0 // indirect
 	github.com/tidwall/gjson v1.18.0 // indirect
 	github.com/tidwall/match v1.1.1 // indirect
 	github.com/tidwall/pretty v1.2.1 // indirect
 	github.com/tidwall/sjson v1.2.5 // indirect
 	go.opencensus.io v0.24.0 // indirect
+	go.uber.org/atomic v1.11.0 // indirect
 	golang.org/x/crypto v0.47.0 // indirect
 	golang.org/x/net v0.49.0 // indirect
 	golang.org/x/sync v0.19.0 // indirect
--- a/go.sum
+++ b/go.sum
@@ -7,21 +7,31 @@ cloud.google.com/go/compute/metadata v0.5.0 h1:Zr0eK8JbFv6+Wi4ilXAR8FJ3wyNdpxHKJ
 cloud.google.com/go/compute/metadata v0.5.0/go.mod h1:aHnloV2TPI38yx4s9+wAZhHykWvVCfu7hQbF+9CWoiY=
 filippo.io/edwards25519 v1.1.0 h1:FNf4tywRC1HmFuKW5xopWpigGjJKiJSV0Cqo0cJWDaA=
 filippo.io/edwards25519 v1.1.0/go.mod h1:BxyFTGdWcka3PhytdK4V28tE5sGfRvvvRV7EaN4VDT4=
-github.com/Azure/azure-sdk-for-go/sdk/ai/azopenai v0.9.0 h1:t/DLMixbb8ygU11RAHJ8quXwJD7FwlC7+u6XodmSi1w=
-github.com/Azure/azure-sdk-for-go/sdk/ai/azopenai v0.9.0/go.mod h1:Bb4vy1c7tXIqFrypNxCO7I5xlDSbpQiOWu/XvF5htP8=
 github.com/Azure/azure-sdk-for-go/sdk/azcore v1.21.0 h1:fou+2+WFTib47nS+nz/ozhEBnvU96bKHy6LjRsY4E28=
 github.com/Azure/azure-sdk-for-go/sdk/azcore v1.21.0/go.mod h1:t76Ruy8AHvUAC8GfMWJMa0ElSbuIcO03NLpynfbgsPA=
+github.com/Azure/azure-sdk-for-go/sdk/azidentity v1.10.1 h1:B+blDbyVIG3WaikNxPnhPiJ1MThR03b3vKGtER95TP4=
+github.com/Azure/azure-sdk-for-go/sdk/azidentity v1.10.1/go.mod h1:JdM5psgjfBf5fo2uWOZhflPWyDBZ/O/CNAH9CtsuZE4=
 github.com/Azure/azure-sdk-for-go/sdk/internal v1.11.2 h1:9iefClla7iYpfYWdzPCRDozdmndjTm8DXdpCzPajMgA=
 github.com/Azure/azure-sdk-for-go/sdk/internal v1.11.2/go.mod h1:XtLgD3ZD34DAaVIIAyG3objl5DynM3CQ/vMcbBNJZGI=
+github.com/AzureAD/microsoft-authentication-library-for-go v1.4.2 h1:oygO0locgZJe7PpYPXT5A29ZkwJaPqcva7BVeemZOZs=
+github.com/AzureAD/microsoft-authentication-library-for-go v1.4.2/go.mod h1:wP83P5OoQ5p6ip3ScPr0BAq0BvuPAvacpEuSzyouqAI=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/anthropics/anthropic-sdk-go v1.26.0 h1:oUTzFaUpAevfuELAP1sjL6CQJ9HHAfT7CoSYSac11PY=
 github.com/anthropics/anthropic-sdk-go v1.26.0/go.mod h1:qUKmaW+uuPB64iy1l+4kOSvaLqPXnHTTBKH6RVZ7q5Q=
+github.com/bsm/ginkgo/v2 v2.12.0 h1:Ny8MWAHyOepLGlLKYmXG4IEkioBysk6GpaRTLC8zwWs=
+github.com/bsm/ginkgo/v2 v2.12.0/go.mod h1:SwYbGRRDovPVboqFv0tPTcG1sN61LM1Z4ARdbAV9g4c=
+github.com/bsm/gomega v1.27.10 h1:yeMWxP2pV2fG3FgAODIY8EiRE3dy0aeFYt4l7wh6yKA=
+github.com/bsm/gomega v1.27.10/go.mod h1:JyEr/xRbxbtgWNi8tIEVPUYZ5Dzef52k01W3YH0H+O0=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
+github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
+github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/cncf/udpa/go v0.0.0-20191209042840-269d4d468f6f/go.mod h1:M8M6+tZqaGXZJjfX53e64911xZQV5JYwmTeXPW+k8Sc=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f h1:lO4WD4F/rVNCu3HqELle0jiPLLBs70cWOduZpkS1E78=
+github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f/go.mod h1:cuUVRXasLTGF7a8hSLbxyZXjz+1KgoB3wDUb6vlszIc=
 github.com/dnaeon/go-vcr v1.2.0 h1:zHCHvJYTMh1N7xnV7zf1m1GPBF9Ad0Jk/whtQ1663qI=
 github.com/dnaeon/go-vcr v1.2.0/go.mod h1:R4UdLID7HZT3taECzJs4YgbbH6PIGXB6W/sc5OLb6RQ=
 github.com/envoyproxy/go-control-plane v0.9.0/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
@@ -71,15 +81,29 @@ github.com/jackc/pgx/v5 v5.8.0 h1:TYPDoleBBme0xGSAX3/+NujXXtpZn9HBONkQC7IEZSo=
 github.com/jackc/pgx/v5 v5.8.0/go.mod h1:QVeDInX2m9VyzvNeiCJVjCkNFqzsNb43204HshNSZKw=
 github.com/jackc/puddle/v2 v2.2.2 h1:PR8nw+E/1w0GLuRFSmiioY6UooMp6KJv0/61nB7icHo=
 github.com/jackc/puddle/v2 v2.2.2/go.mod h1:vriiEXHvEE654aYKXXjOvZM39qJ0q+azkZFrfEOc3H4=
+github.com/klauspost/cpuid/v2 v2.0.9 h1:lgaqFMSdTdQYdZ04uHyN2d/eKdOMyi2YLSvlQIBFYa4=
+github.com/klauspost/cpuid/v2 v2.0.9/go.mod h1:FInQzS24/EEf25PyTYn52gqo7WaD8xa0213Md/qVLRg=
+github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
+github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0SNc=
+github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=
 github.com/mattn/go-sqlite3 v1.14.34 h1:3NtcvcUnFBPsuRcno8pUtupspG/GM+9nZ88zgJcp6Zk=
 github.com/mattn/go-sqlite3 v1.14.34/go.mod h1:Uh1q+B4BYcTPb+yiD3kU8Ct7aC0hY9fxUwlHK0RXw+Y=
 github.com/openai/openai-go v1.12.0 h1:NBQCnXzqOTv5wsgNC36PrFEiskGfO5wccfCWDo9S1U0=
 github.com/openai/openai-go v1.12.0/go.mod h1:g461MYGXEXBVdV5SaR/5tNzNbSfwTBBefwc+LlDCK0Y=
 github.com/openai/openai-go/v3 v3.2.0 h1:2AbqFUCsoW2pm/2pUtPRuwK89dnoGHaQokzWsfoQO/U=
 github.com/openai/openai-go/v3 v3.2.0/go.mod h1:UOpNxkqC9OdNXNUfpNByKOtB4jAL0EssQXq5p8gO0Xs=
+github.com/pkg/browser v0.0.0-20240102092130-5ac0b6a4141c h1:+mdjkGKdHQG3305AYmdv1U2eRNDiU2ErMBj1gwrq8eQ=
+github.com/pkg/browser v0.0.0-20240102092130-5ac0b6a4141c/go.mod h1:7rwL4CYBLnjLxUqIJNnCWiEdr3bn6IUYi15bNlnbCCU=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
+github.com/redis/go-redis/v9 v9.18.0 h1:pMkxYPkEbMPwRdenAzUNyFNrDgHx9U+DrBabWNfSRQs=
+github.com/redis/go-redis/v9 v9.18.0/go.mod h1:k3ufPphLU5YXwNTUcCRXGxUoF1fqxnhFQmscfkCoDA0=
+github.com/rogpeppe/go-internal v1.12.0 h1:exVL4IDcn6na9z1rAb56Vxr+CgyK3nn3O+epU5NdKM8=
+github.com/rogpeppe/go-internal v1.12.0/go.mod h1:E+RYuTGaKKdloAfM02xzb0FW3Paa99yedzYV+kq4uf4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
 github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
@@ -88,9 +112,8 @@ github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/
 github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
 github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
-github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
-github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
+github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
 github.com/tidwall/gjson v1.14.2/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
 github.com/tidwall/gjson v1.18.0 h1:FIDeeyB800efLX89e5a8Y0BNH+LOngJyGrIWxG2FKQY=
 github.com/tidwall/gjson v1.18.0/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
@@ -101,12 +124,14 @@ github.com/tidwall/pretty v1.2.1 h1:qjsOFOWWQl+N3RsoF5/ssm1pHmJJwhjlSbZ51I6wMl4=
 github.com/tidwall/pretty v1.2.1/go.mod h1:ITEVvHYasfjBbM0u2Pg8T2nJnzm8xPwvNhhsoaGGjNU=
 github.com/tidwall/sjson v1.2.5 h1:kLy8mja+1c9jlljvWTlSazM7cKDRfJuR/bOJhcY5NcY=
 github.com/tidwall/sjson v1.2.5/go.mod h1:Fvgq9kS/6ociJEDnK0Fk1cpYF4FIW6ZF7LAe+6jwd28=
+github.com/zeebo/xxh3 v1.0.2 h1:xZmwmqxHZA8AI603jOQ0tMqmBr9lPeFwGg6d+xy9DC0=
+github.com/zeebo/xxh3 v1.0.2/go.mod h1:5NWz9Sef7zIDm2JHfFlcQvNekmcEl9ekUZQQKCYaDcA=
 go.opencensus.io v0.24.0 h1:y73uSU6J157QMP2kn2r30vwW1A2W2WFwSCGnAVxeaD0=
 go.opencensus.io v0.24.0/go.mod h1:vNK8G9p7aAivkbmorf4v+7Hgx+Zs0yY+0fOtgBfjQKo=
+go.uber.org/atomic v1.11.0 h1:ZvwS0R+56ePWxUNi+Atn9dWONBPp/AUETXlHW0DxSjE=
+go.uber.org/atomic v1.11.0/go.mod h1:LUxbIzbOniOlMKjJjyPfpl4v+PKK2cNJn91OQbhoJI0=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
-golang.org/x/crypto v0.40.0 h1:r4x+VvoG5Fm+eJcxMaY8CQM7Lb0l1lsmjGBQ6s8BfKM=
-golang.org/x/crypto v0.40.0/go.mod h1:Qr1vMER5WyS2dfPHAlsOj01wgLbsyWtFn/aY+5+ZdxY=
 golang.org/x/crypto v0.47.0 h1:V6e3FRj+n4dbpw86FJ8Fv7XVOql7TEwpHapKoMJ/GO8=
 golang.org/x/crypto v0.47.0/go.mod h1:ff3Y9VzzKbwSSEzWqJsJVBnWmRwRSHt/6Op5n9bQc4A=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
@@ -119,30 +144,22 @@ golang.org/x/net v0.0.0-20190213061140-3a22650c66bd/go.mod h1:mL1N/T3taQHkDXs73r
 golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20201110031124-69a78807bb2b/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
-golang.org/x/net v0.41.0 h1:vBTly1HeNPEn3wtREYfy4GZ/NECgw2Cnl+nK6Nz3uvw=
-golang.org/x/net v0.41.0/go.mod h1:B/K4NNqkfmg07DQYrbwvSluqCJOOXwUjeb/5lOisjbA=
 golang.org/x/net v0.49.0 h1:eeHFmOGUTtaaPSGNmjBKpbng9MulQsJURQUAfUwY++o=
 golang.org/x/net v0.49.0/go.mod h1:/ysNB2EvaqvesRkuLAyjI1ycPZlQHM3q01F02UY/MV8=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.16.0 h1:ycBJEhp9p4vXvUZNszeOq0kGTPghopOL8q0fq3vstxw=
-golang.org/x/sync v0.16.0/go.mod h1:1dzgHSNfp02xaA81J2MS99Qcpr2w7fw1gpm99rleRqA=
 golang.org/x/sync v0.19.0 h1:vV+1eWNmZ5geRlYjzm2adRgW2/mcpevXNg50YZtPCE4=
 golang.org/x/sync v0.19.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.34.0 h1:H5Y5sJ2L2JRdyv7ROF1he/lPdvFsd0mJHFw2ThKHxLA=
-golang.org/x/sys v0.34.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
 golang.org/x/sys v0.40.0 h1:DBZZqJ2Rkml6QMQsZywtnjnnGvHza6BTfYFWY9kjEWQ=
 golang.org/x/sys v0.40.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
-golang.org/x/text v0.27.0 h1:4fGWRpyh641NLlecmyl4LOe6yDdfaYNrGb2zdfo4JV4=
-golang.org/x/text v0.27.0/go.mod h1:1D28KMCvyooCX9hBiosv5Tz/+YLxj0j7XhWjpSUF7CU=
 golang.org/x/text v0.33.0 h1:B3njUFyqtHDUI5jMn1YIr5B0IE2U0qck04r6d4KPAxE=
 golang.org/x/text v0.33.0/go.mod h1:LuMebE6+rBincTi9+xWTY8TztLzKHc/9C1uBCG27+q8=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
@@ -178,8 +195,9 @@ google.golang.org/protobuf v1.23.1-0.20200526195155-81db48ad09cc/go.mod h1:EGpAD
 google.golang.org/protobuf v1.25.0/go.mod h1:9JNX74DMeImyA3h4bdi1ymwjUzf21/xIlbajtzgsN7c=
 google.golang.org/protobuf v1.34.2 h1:6xV6lTsCfpGD21XK49h7MhtcApnLqkfYgPcdHftf6hg=
 google.golang.org/protobuf v1.34.2/go.mod h1:qYOHts0dSfpeUzUFpOMr/WGzszTmLH+DiWniOlNbLDw=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
 gopkg.in/yaml.v2 v2.2.8 h1:obN1ZagJSUGI0Ek/LBmuj4SNLPfIny3KsKFopxRdj10=
 gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
--- a/internal/api/types.go
+++ b/internal/api/types.go
@@ -96,6 +96,7 @@ type InputItem struct {
 type Message struct {
 	Role    string         `json:"role"`
 	Content []ContentBlock `json:"content"`
+	CallID  string         `json:"call_id,omitempty"` // for tool messages
 }

 // ContentBlock is a typed content element.
@@ -138,6 +139,7 @@ func (r *ResponseRequest) NormalizeInput() []Message {
 			msgs = append(msgs, Message{
 				Role:    "tool",
 				Content: []ContentBlock{{Type: "input_text", Text: item.Output}},
+				CallID:  item.CallID,
 			})
 		}
 	}
@@ -188,11 +190,14 @@ type Response struct {

 // OutputItem represents a typed item in the response output.
 type OutputItem struct {
-	ID      string        `json:"id"`
-	Type    string        `json:"type"`
-	Status  string        `json:"status"`
-	Role    string        `json:"role,omitempty"`
-	Content []ContentPart `json:"content,omitempty"`
+	ID        string        `json:"id"`
+	Type      string        `json:"type"`
+	Status    string        `json:"status"`
+	Role      string        `json:"role,omitempty"`
+	Content   []ContentPart `json:"content,omitempty"`
+	CallID    string        `json:"call_id,omitempty"`    // for function_call
+	Name      string        `json:"name,omitempty"`       // for function_call
+	Arguments string        `json:"arguments,omitempty"`  // for function_call
 }

 // ContentPart is a content block within an output item.
@@ -259,6 +264,7 @@ type StreamEvent struct {
 	Part           *ContentPart `json:"part,omitempty"`
 	Delta          string       `json:"delta,omitempty"`
 	Text           string       `json:"text,omitempty"`
+	Arguments      string       `json:"arguments,omitempty"` // for function_call_arguments.done
 }

 // ============================================================
@@ -267,19 +273,36 @@ type StreamEvent struct {

 // ProviderResult is returned by Provider.Generate.
 type ProviderResult struct {
-	ID    string
-	Model string
-	Text  string
-	Usage Usage
+	ID        string
+	Model     string
+	Text      string
+	Usage     Usage
+	ToolCalls []ToolCall
 }

 // ProviderStreamDelta is sent through the stream channel.
 type ProviderStreamDelta struct {
-	ID    string
-	Model string
-	Text  string
-	Done  bool
-	Usage *Usage
+	ID            string
+	Model         string
+	Text          string
+	Done          bool
+	Usage         *Usage
+	ToolCallDelta *ToolCallDelta
+}
+
+// ToolCall represents a function call from the model.
+type ToolCall struct {
+	ID        string
+	Name      string
+	Arguments string // JSON string
+}
+
+// ToolCallDelta represents a streaming chunk of a tool call.
+type ToolCallDelta struct {
+	Index     int
+	ID        string
+	Name      string
+	Arguments string
 }

 // ============================================================
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -18,12 +18,12 @@ type Config struct {

 // ConversationConfig controls conversation storage.
 type ConversationConfig struct {
-	// Store is the storage backend: "memory" (default) or "sql".
+	// Store is the storage backend: "memory" (default), "sql", or "redis".
 	Store string `yaml:"store"`
 	// TTL is the conversation expiration duration (e.g. "1h", "30m"). Defaults to "1h".
 	TTL string `yaml:"ttl"`
-	// DSN is the database connection string, required when store is "sql".
-	// Examples: "conversations.db" (SQLite), "postgres://user:pass@host/db".
+	// DSN is the database/Redis connection string, required when store is "sql" or "redis".
+	// Examples: "conversations.db" (SQLite), "postgres://user:pass@host/db", "redis://:password@localhost:6379/0".
 	DSN string `yaml:"dsn"`
 	// Driver is the SQL driver name, required when store is "sql".
 	// Examples: "sqlite3", "postgres", "mysql".
@@ -48,6 +48,8 @@ type ProviderEntry struct {
 	APIKey     string `yaml:"api_key"`
 	Endpoint   string `yaml:"endpoint"`
 	APIVersion string `yaml:"api_version"`
+	Project    string `yaml:"project"`  // For Vertex AI
+	Location   string `yaml:"location"` // For Vertex AI
 }

 // ModelEntry maps a model name to a provider entry.
@@ -78,6 +80,12 @@ type AzureAnthropicConfig struct {
 	Model    string `yaml:"model"`
 }

+// VertexAIConfig contains Vertex AI-specific settings used internally by the Google provider.
+type VertexAIConfig struct {
+	Project  string `yaml:"project"`
+	Location string `yaml:"location"`
+}
+
 // Load reads and parses a YAML configuration file, expanding ${VAR} env references.
 func Load(path string) (*Config, error) {
 	data, err := os.ReadFile(path)
--- a/internal/conversation/conversation.go
+++ b/internal/conversation/conversation.go
@@ -4,15 +4,15 @@ import (
 	"sync"
 	"time"

-	"github.com/yourusername/go-llm-gateway/internal/api"
+	"github.com/ajac-zero/latticelm/internal/api"
 )

 // Store defines the interface for conversation storage backends.
 type Store interface {
-	Get(id string) (*Conversation, bool)
-	Create(id string, model string, messages []api.Message) *Conversation
-	Append(id string, messages ...api.Message) (*Conversation, bool)
-	Delete(id string)
+	Get(id string) (*Conversation, error)
+	Create(id string, model string, messages []api.Message) (*Conversation, error)
+	Append(id string, messages ...api.Message) (*Conversation, error)
+	Delete(id string) error
 	Size() int
 }

@@ -47,55 +47,93 @@ func NewMemoryStore(ttl time.Duration) *MemoryStore {
 	return s
 }

-// Get retrieves a conversation by ID.
-func (s *MemoryStore) Get(id string) (*Conversation, bool) {
+// Get retrieves a conversation by ID. Returns a deep copy to prevent data races.
+func (s *MemoryStore) Get(id string) (*Conversation, error) {
 	s.mu.RLock()
 	defer s.mu.RUnlock()

 	conv, ok := s.conversations[id]
-	return conv, ok
+	if !ok {
+		return nil, nil
+	}
+
+	// Return a deep copy to prevent data races
+	msgsCopy := make([]api.Message, len(conv.Messages))
+	copy(msgsCopy, conv.Messages)
+
+	return &Conversation{
+		ID:        conv.ID,
+		Messages:  msgsCopy,
+		Model:     conv.Model,
+		CreatedAt: conv.CreatedAt,
+		UpdatedAt: conv.UpdatedAt,
+	}, nil
 }

 // Create creates a new conversation with the given messages.
-func (s *MemoryStore) Create(id string, model string, messages []api.Message) *Conversation {
+func (s *MemoryStore) Create(id string, model string, messages []api.Message) (*Conversation, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()

 	now := time.Now()
+
+	// Store a copy to prevent external modifications
+	msgsCopy := make([]api.Message, len(messages))
+	copy(msgsCopy, messages)
+
 	conv := &Conversation{
 		ID:        id,
-		Messages:  messages,
+		Messages:  msgsCopy,
 		Model:     model,
 		CreatedAt: now,
 		UpdatedAt: now,
 	}

 	s.conversations[id] = conv
-	return conv
+
+	// Return a copy
+	return &Conversation{
+		ID:        id,
+		Messages:  messages,
+		Model:     model,
+		CreatedAt: now,
+		UpdatedAt: now,
+	}, nil
 }

 // Append adds new messages to an existing conversation.
-func (s *MemoryStore) Append(id string, messages ...api.Message) (*Conversation, bool) {
+func (s *MemoryStore) Append(id string, messages ...api.Message) (*Conversation, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()

 	conv, ok := s.conversations[id]
 	if !ok {
-		return nil, false
+		return nil, nil
 	}

 	conv.Messages = append(conv.Messages, messages...)
 	conv.UpdatedAt = time.Now()

-	return conv, true
+	// Return a deep copy
+	msgsCopy := make([]api.Message, len(conv.Messages))
+	copy(msgsCopy, conv.Messages)
+
+	return &Conversation{
+		ID:        conv.ID,
+		Messages:  msgsCopy,
+		Model:     conv.Model,
+		CreatedAt: conv.CreatedAt,
+		UpdatedAt: conv.UpdatedAt,
+	}, nil
 }

 // Delete removes a conversation from the store.
-func (s *MemoryStore) Delete(id string) {
+func (s *MemoryStore) Delete(id string) error {
 	s.mu.Lock()
 	defer s.mu.Unlock()

 	delete(s.conversations, id)
+	return nil
 }

 // cleanup periodically removes expired conversations.
--- a/internal/conversation/redis_store.go
+++ b/internal/conversation/redis_store.go
@@ -0,0 +1,124 @@
+package conversation
+
+import (
+	"context"
+	"encoding/json"
+	"time"
+
+	"github.com/ajac-zero/latticelm/internal/api"
+	"github.com/redis/go-redis/v9"
+)
+
+// RedisStore manages conversation history in Redis with automatic expiration.
+type RedisStore struct {
+	client *redis.Client
+	ttl    time.Duration
+	ctx    context.Context
+}
+
+// NewRedisStore creates a Redis-backed conversation store.
+func NewRedisStore(client *redis.Client, ttl time.Duration) *RedisStore {
+	return &RedisStore{
+		client: client,
+		ttl:    ttl,
+		ctx:    context.Background(),
+	}
+}
+
+// key returns the Redis key for a conversation ID.
+func (s *RedisStore) key(id string) string {
+	return "conv:" + id
+}
+
+// Get retrieves a conversation by ID from Redis.
+func (s *RedisStore) Get(id string) (*Conversation, error) {
+	data, err := s.client.Get(s.ctx, s.key(id)).Bytes()
+	if err == redis.Nil {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	var conv Conversation
+	if err := json.Unmarshal(data, &conv); err != nil {
+		return nil, err
+	}
+
+	return &conv, nil
+}
+
+// Create creates a new conversation with the given messages.
+func (s *RedisStore) Create(id string, model string, messages []api.Message) (*Conversation, error) {
+	now := time.Now()
+	conv := &Conversation{
+		ID:        id,
+		Messages:  messages,
+		Model:     model,
+		CreatedAt: now,
+		UpdatedAt: now,
+	}
+
+	data, err := json.Marshal(conv)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := s.client.Set(s.ctx, s.key(id), data, s.ttl).Err(); err != nil {
+		return nil, err
+	}
+
+	return conv, nil
+}
+
+// Append adds new messages to an existing conversation.
+func (s *RedisStore) Append(id string, messages ...api.Message) (*Conversation, error) {
+	conv, err := s.Get(id)
+	if err != nil {
+		return nil, err
+	}
+	if conv == nil {
+		return nil, nil
+	}
+
+	conv.Messages = append(conv.Messages, messages...)
+	conv.UpdatedAt = time.Now()
+
+	data, err := json.Marshal(conv)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := s.client.Set(s.ctx, s.key(id), data, s.ttl).Err(); err != nil {
+		return nil, err
+	}
+
+	return conv, nil
+}
+
+// Delete removes a conversation from Redis.
+func (s *RedisStore) Delete(id string) error {
+	return s.client.Del(s.ctx, s.key(id)).Err()
+}
+
+// Size returns the number of active conversations in Redis.
+func (s *RedisStore) Size() int {
+	var count int
+	var cursor uint64
+
+	for {
+		keys, nextCursor, err := s.client.Scan(s.ctx, cursor, "conv:*", 100).Result()
+		if err != nil {
+			return 0
+		}
+
+		count += len(keys)
+		cursor = nextCursor
+
+		if cursor == 0 {
+			break
+		}
+	}
+
+	return count
+}
--- a/internal/conversation/sql_store.go
+++ b/internal/conversation/sql_store.go
@@ -5,7 +5,7 @@ import (
 	"encoding/json"
 	"time"

-	"github.com/yourusername/go-llm-gateway/internal/api"
+	"github.com/ajac-zero/latticelm/internal/api"
 )

 // sqlDialect holds driver-specific SQL statements.
@@ -65,28 +65,36 @@ func NewSQLStore(db *sql.DB, driver string, ttl time.Duration) (*SQLStore, error
 	return s, nil
 }

-func (s *SQLStore) Get(id string) (*Conversation, bool) {
+func (s *SQLStore) Get(id string) (*Conversation, error) {
 	row := s.db.QueryRow(s.dialect.getByID, id)

 	var conv Conversation
 	var msgJSON string
 	err := row.Scan(&conv.ID, &conv.Model, &msgJSON, &conv.CreatedAt, &conv.UpdatedAt)
+	if err == sql.ErrNoRows {
+		return nil, nil
+	}
 	if err != nil {
-		return nil, false
+		return nil, err
 	}

 	if err := json.Unmarshal([]byte(msgJSON), &conv.Messages); err != nil {
-		return nil, false
+		return nil, err
 	}

-	return &conv, true
+	return &conv, nil
 }

-func (s *SQLStore) Create(id string, model string, messages []api.Message) *Conversation {
+func (s *SQLStore) Create(id string, model string, messages []api.Message) (*Conversation, error) {
 	now := time.Now()
-	msgJSON, _ := json.Marshal(messages)
+	msgJSON, err := json.Marshal(messages)
+	if err != nil {
+		return nil, err
+	}

-	_, _ = s.db.Exec(s.dialect.upsert, id, model, string(msgJSON), now, now)
+	if _, err := s.db.Exec(s.dialect.upsert, id, model, string(msgJSON), now, now); err != nil {
+		return nil, err
+	}

 	return &Conversation{
 		ID:        id,
@@ -94,26 +102,36 @@ func (s *SQLStore) Create(id string, model string, messages []api.Message) *Conv
 		Model:     model,
 		CreatedAt: now,
 		UpdatedAt: now,
-	}
+	}, nil
 }

-func (s *SQLStore) Append(id string, messages ...api.Message) (*Conversation, bool) {
-	conv, ok := s.Get(id)
-	if !ok {
-		return nil, false
+func (s *SQLStore) Append(id string, messages ...api.Message) (*Conversation, error) {
+	conv, err := s.Get(id)
+	if err != nil {
+		return nil, err
+	}
+	if conv == nil {
+		return nil, nil
 	}

 	conv.Messages = append(conv.Messages, messages...)
 	conv.UpdatedAt = time.Now()

-	msgJSON, _ := json.Marshal(conv.Messages)
-	_, _ = s.db.Exec(s.dialect.update, string(msgJSON), conv.UpdatedAt, id)
+	msgJSON, err := json.Marshal(conv.Messages)
+	if err != nil {
+		return nil, err
+	}

-	return conv, true
+	if _, err := s.db.Exec(s.dialect.update, string(msgJSON), conv.UpdatedAt, id); err != nil {
+		return nil, err
+	}
+
+	return conv, nil
 }

-func (s *SQLStore) Delete(id string) {
-	_, _ = s.db.Exec(s.dialect.deleteByID, id)
+func (s *SQLStore) Delete(id string) error {
+	_, err := s.db.Exec(s.dialect.deleteByID, id)
+	return err
 }

 func (s *SQLStore) Size() int {
--- a/internal/providers/anthropic/anthropic.go
+++ b/internal/providers/anthropic/anthropic.go
@@ -2,13 +2,14 @@ package anthropic

 import (
 	"context"
+	"encoding/json"
 	"fmt"

 	"github.com/anthropics/anthropic-sdk-go"
 	"github.com/anthropics/anthropic-sdk-go/option"

-	"github.com/yourusername/go-llm-gateway/internal/api"
-	"github.com/yourusername/go-llm-gateway/internal/config"
+	"github.com/ajac-zero/latticelm/internal/api"
+	"github.com/ajac-zero/latticelm/internal/config"
 )

 const Name = "anthropic"
@@ -85,6 +86,11 @@ func (p *Provider) Generate(ctx context.Context, messages []api.Message, req *ap
 			anthropicMsgs = append(anthropicMsgs, anthropic.NewUserMessage(anthropic.NewTextBlock(content)))
 		case "assistant":
 			anthropicMsgs = append(anthropicMsgs, anthropic.NewAssistantMessage(anthropic.NewTextBlock(content)))
+		case "tool":
+			// Tool results must be in user message with tool_result blocks
+			anthropicMsgs = append(anthropicMsgs, anthropic.NewUserMessage(
+				anthropic.NewToolResultBlock(msg.CallID, content, false),
+			))
 		case "system", "developer":
 			system = content
 		}
@@ -116,24 +122,55 @@ func (p *Provider) Generate(ctx context.Context, messages []api.Message, req *ap
 		params.TopP = anthropic.Float(*req.TopP)
 	}

+	// Add tools if present
+	if req.Tools != nil && len(req.Tools) > 0 {
+		tools, err := parseTools(req)
+		if err != nil {
+			return nil, fmt.Errorf("parse tools: %w", err)
+		}
+		params.Tools = tools
+	}
+
+	// Add tool_choice if present
+	if req.ToolChoice != nil && len(req.ToolChoice) > 0 {
+		toolChoice, err := parseToolChoice(req)
+		if err != nil {
+			return nil, fmt.Errorf("parse tool_choice: %w", err)
+		}
+		params.ToolChoice = toolChoice
+	}
+
 	// Call Anthropic API
 	resp, err := p.client.Messages.New(ctx, params)
 	if err != nil {
 		return nil, fmt.Errorf("anthropic api error: %w", err)
 	}

-	// Extract text from response
+	// Extract text and tool calls from response
 	var text string
+	var toolCalls []api.ToolCall
+
 	for _, block := range resp.Content {
-		if block.Type == "text" {
-			text += block.Text
+		switch block.Type {
+		case "text":
+			text += block.AsText().Text
+		case "tool_use":
+			// Extract tool calls
+			toolUse := block.AsToolUse()
+			argsJSON, _ := json.Marshal(toolUse.Input)
+			toolCalls = append(toolCalls, api.ToolCall{
+				ID:        toolUse.ID,
+				Name:      toolUse.Name,
+				Arguments: string(argsJSON),
+			})
 		}
 	}

 	return &api.ProviderResult{
-		ID:    resp.ID,
-		Model: string(resp.Model),
-		Text:  text,
+		ID:        resp.ID,
+		Model:     string(resp.Model),
+		Text:      text,
+		ToolCalls: toolCalls,
 		Usage: api.Usage{
 			InputTokens:  int(resp.Usage.InputTokens),
 			OutputTokens: int(resp.Usage.OutputTokens),
@@ -177,6 +214,11 @@ func (p *Provider) GenerateStream(ctx context.Context, messages []api.Message, r
 				anthropicMsgs = append(anthropicMsgs, anthropic.NewUserMessage(anthropic.NewTextBlock(content)))
 			case "assistant":
 				anthropicMsgs = append(anthropicMsgs, anthropic.NewAssistantMessage(anthropic.NewTextBlock(content)))
+			case "tool":
+				// Tool results must be in user message with tool_result blocks
+				anthropicMsgs = append(anthropicMsgs, anthropic.NewUserMessage(
+					anthropic.NewToolResultBlock(msg.CallID, content, false),
+				))
 			case "system", "developer":
 				system = content
 			}
@@ -208,19 +250,77 @@ func (p *Provider) GenerateStream(ctx context.Context, messages []api.Message, r
 			params.TopP = anthropic.Float(*req.TopP)
 		}

+		// Add tools if present
+		if req.Tools != nil && len(req.Tools) > 0 {
+			tools, err := parseTools(req)
+			if err != nil {
+				errChan <- fmt.Errorf("parse tools: %w", err)
+				return
+			}
+			params.Tools = tools
+		}
+
+		// Add tool_choice if present
+		if req.ToolChoice != nil && len(req.ToolChoice) > 0 {
+			toolChoice, err := parseToolChoice(req)
+			if err != nil {
+				errChan <- fmt.Errorf("parse tool_choice: %w", err)
+				return
+			}
+			params.ToolChoice = toolChoice
+		}
+
 		// Create stream
 		stream := p.client.Messages.NewStreaming(ctx, params)

+		// Track content block index and tool call state
+		var contentBlockIndex int
+
 		// Process stream
 		for stream.Next() {
 			event := stream.Current()

-			if event.Type == "content_block_delta" && event.Delta.Type == "text_delta" {
-				select {
-				case deltaChan <- &api.ProviderStreamDelta{Text: event.Delta.Text}:
-				case <-ctx.Done():
-					errChan <- ctx.Err()
-					return
+			switch event.Type {
+			case "content_block_start":
+				// New content block (text or tool_use)
+				contentBlockIndex = int(event.Index)
+				if event.ContentBlock.Type == "tool_use" {
+					// Send tool call delta with ID and name
+					toolUse := event.ContentBlock.AsToolUse()
+					delta := &api.ToolCallDelta{
+						Index: contentBlockIndex,
+						ID:    toolUse.ID,
+						Name:  toolUse.Name,
+					}
+					select {
+					case deltaChan <- &api.ProviderStreamDelta{ToolCallDelta: delta}:
+					case <-ctx.Done():
+						errChan <- ctx.Err()
+						return
+					}
+				}
+
+			case "content_block_delta":
+				if event.Delta.Type == "text_delta" {
+					// Text streaming
+					select {
+					case deltaChan <- &api.ProviderStreamDelta{Text: event.Delta.Text}:
+					case <-ctx.Done():
+						errChan <- ctx.Err()
+						return
+					}
+				} else if event.Delta.Type == "input_json_delta" {
+					// Tool arguments streaming
+					delta := &api.ToolCallDelta{
+						Index:     int(event.Index),
+						Arguments: event.Delta.PartialJSON,
+					}
+					select {
+					case deltaChan <- &api.ProviderStreamDelta{ToolCallDelta: delta}:
+					case <-ctx.Done():
+						errChan <- ctx.Err()
+						return
+					}
 				}
 			}
 		}
--- a/internal/providers/anthropic/convert.go
+++ b/internal/providers/anthropic/convert.go
@@ -0,0 +1,154 @@
+package anthropic
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/ajac-zero/latticelm/internal/api"
+	"github.com/anthropics/anthropic-sdk-go"
+)
+
+// parseTools converts Open Responses tools to Anthropic format
+func parseTools(req *api.ResponseRequest) ([]anthropic.ToolUnionParam, error) {
+	if req.Tools == nil || len(req.Tools) == 0 {
+		return nil, nil
+	}
+
+	var toolDefs []map[string]interface{}
+	if err := json.Unmarshal(req.Tools, &toolDefs); err != nil {
+		return nil, fmt.Errorf("unmarshal tools: %w", err)
+	}
+
+	var tools []anthropic.ToolUnionParam
+	for _, td := range toolDefs {
+		// Extract: name, description, parameters
+		// Note: Anthropic uses "input_schema" instead of "parameters"
+		name, _ := td["name"].(string)
+		desc, _ := td["description"].(string)
+		params, _ := td["parameters"].(map[string]interface{})
+
+		inputSchema := anthropic.ToolInputSchemaParam{
+			Type:       "object",
+			Properties: params["properties"],
+		}
+
+		// Add required fields if present
+		if required, ok := params["required"].([]interface{}); ok {
+			requiredStrs := make([]string, 0, len(required))
+			for _, r := range required {
+				if str, ok := r.(string); ok {
+					requiredStrs = append(requiredStrs, str)
+				}
+			}
+			inputSchema.Required = requiredStrs
+		}
+
+		// Create the tool using ToolUnionParamOfTool
+		tool := anthropic.ToolUnionParamOfTool(inputSchema, name)
+
+		if desc != "" {
+			tool.OfTool.Description = anthropic.String(desc)
+		}
+
+		tools = append(tools, tool)
+	}
+
+	return tools, nil
+}
+
+// parseToolChoice converts Open Responses tool_choice to Anthropic format
+func parseToolChoice(req *api.ResponseRequest) (anthropic.ToolChoiceUnionParam, error) {
+	var result anthropic.ToolChoiceUnionParam
+
+	if req.ToolChoice == nil || len(req.ToolChoice) == 0 {
+		return result, nil
+	}
+
+	var choice interface{}
+	if err := json.Unmarshal(req.ToolChoice, &choice); err != nil {
+		return result, fmt.Errorf("unmarshal tool_choice: %w", err)
+	}
+
+	// Handle string values: "auto", "any", "required"
+	if str, ok := choice.(string); ok {
+		switch str {
+		case "auto":
+			result.OfAuto = &anthropic.ToolChoiceAutoParam{
+				Type: "auto",
+			}
+		case "any", "required":
+			result.OfAny = &anthropic.ToolChoiceAnyParam{
+				Type: "any",
+			}
+		case "none":
+			result.OfNone = &anthropic.ToolChoiceNoneParam{
+				Type: "none",
+			}
+		default:
+			return result, fmt.Errorf("unknown tool_choice string: %s", str)
+		}
+		return result, nil
+	}
+
+	// Handle specific tool selection: {"type": "tool", "function": {"name": "..."}}
+	if obj, ok := choice.(map[string]interface{}); ok {
+		// Check for OpenAI format: {"type": "function", "function": {"name": "..."}}
+		if funcObj, ok := obj["function"].(map[string]interface{}); ok {
+			if name, ok := funcObj["name"].(string); ok {
+				result.OfTool = &anthropic.ToolChoiceToolParam{
+					Type: "tool",
+					Name: name,
+				}
+				return result, nil
+			}
+		}
+
+		// Check for direct name field
+		if name, ok := obj["name"].(string); ok {
+			result.OfTool = &anthropic.ToolChoiceToolParam{
+				Type: "tool",
+				Name: name,
+			}
+			return result, nil
+		}
+	}
+
+	return result, fmt.Errorf("invalid tool_choice format")
+}
+
+// extractToolCalls converts Anthropic content blocks to api.ToolCall
+func extractToolCalls(content []anthropic.ContentBlockUnion) []api.ToolCall {
+	var toolCalls []api.ToolCall
+
+	for _, block := range content {
+		// Check if this is a tool_use block
+		if block.Type == "tool_use" {
+			// Cast to ToolUseBlock to access the fields
+			toolUse := block.AsToolUse()
+
+			// Marshal the input to JSON string for Arguments
+			argsJSON, _ := json.Marshal(toolUse.Input)
+
+			toolCalls = append(toolCalls, api.ToolCall{
+				ID:        toolUse.ID,
+				Name:      toolUse.Name,
+				Arguments: string(argsJSON),
+			})
+		}
+	}
+
+	return toolCalls
+}
+
+// extractToolCallDelta extracts tool call delta from streaming content block delta
+func extractToolCallDelta(delta anthropic.RawContentBlockDeltaUnion, index int) *api.ToolCallDelta {
+	// Check if this is an input_json_delta (streaming tool arguments)
+	if delta.Type == "input_json_delta" {
+		return &api.ToolCallDelta{
+			Index:     index,
+			Arguments: delta.PartialJSON,
+		}
+	}
+
+	return nil
+}
--- a/internal/providers/anthropic/convert_test.go
+++ b/internal/providers/anthropic/convert_test.go
@@ -0,0 +1,119 @@
+package anthropic
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/ajac-zero/latticelm/internal/api"
+)
+
+func TestParseTools(t *testing.T) {
+	// Create a sample tool definition
+	toolsJSON := `[{
+		"type": "function",
+		"name": "get_weather",
+		"description": "Get the weather for a location",
+		"parameters": {
+			"type": "object",
+			"properties": {
+				"location": {
+					"type": "string",
+					"description": "The city and state"
+				}
+			},
+			"required": ["location"]
+		}
+	}]`
+
+	req := &api.ResponseRequest{
+		Tools: json.RawMessage(toolsJSON),
+	}
+
+	tools, err := parseTools(req)
+	if err != nil {
+		t.Fatalf("parseTools failed: %v", err)
+	}
+
+	if len(tools) != 1 {
+		t.Fatalf("expected 1 tool, got %d", len(tools))
+	}
+
+	tool := tools[0]
+	if tool.OfTool == nil {
+		t.Fatal("expected OfTool to be set")
+	}
+
+	if tool.OfTool.Name != "get_weather" {
+		t.Errorf("expected name 'get_weather', got '%s'", tool.OfTool.Name)
+	}
+
+	desc := tool.GetDescription()
+	if desc == nil || *desc != "Get the weather for a location" {
+		t.Errorf("expected description 'Get the weather for a location', got '%v'", desc)
+	}
+
+	if len(tool.OfTool.InputSchema.Required) != 1 || tool.OfTool.InputSchema.Required[0] != "location" {
+		t.Errorf("expected required=['location'], got %v", tool.OfTool.InputSchema.Required)
+	}
+}
+
+func TestParseToolChoice(t *testing.T) {
+	tests := []struct {
+		name        string
+		choiceJSON  string
+		expectAuto  bool
+		expectAny   bool
+		expectTool  bool
+		expectedName string
+	}{
+		{
+			name:       "auto",
+			choiceJSON: `"auto"`,
+			expectAuto: true,
+		},
+		{
+			name:       "any",
+			choiceJSON: `"any"`,
+			expectAny:  true,
+		},
+		{
+			name:       "required",
+			choiceJSON: `"required"`,
+			expectAny:  true,
+		},
+		{
+			name:         "specific tool",
+			choiceJSON:   `{"type": "function", "function": {"name": "get_weather"}}`,
+			expectTool:   true,
+			expectedName: "get_weather",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			req := &api.ResponseRequest{
+				ToolChoice: json.RawMessage(tt.choiceJSON),
+			}
+
+			choice, err := parseToolChoice(req)
+			if err != nil {
+				t.Fatalf("parseToolChoice failed: %v", err)
+			}
+
+			if tt.expectAuto && choice.OfAuto == nil {
+				t.Error("expected OfAuto to be set")
+			}
+			if tt.expectAny && choice.OfAny == nil {
+				t.Error("expected OfAny to be set")
+			}
+			if tt.expectTool {
+				if choice.OfTool == nil {
+					t.Fatal("expected OfTool to be set")
+				}
+				if choice.OfTool.Name != tt.expectedName {
+					t.Errorf("expected name '%s', got '%s'", tt.expectedName, choice.OfTool.Name)
+				}
+			}
+		})
+	}
+}
--- a/internal/providers/google/convert.go
+++ b/internal/providers/google/convert.go
@@ -0,0 +1,212 @@
+package google
+
+import (
+	"encoding/json"
+	"fmt"
+	"math/rand"
+	"time"
+
+	"google.golang.org/genai"
+
+	"github.com/ajac-zero/latticelm/internal/api"
+)
+
+// parseTools converts generic tool definitions from req.Tools (JSON) to Google's []*genai.Tool format.
+func parseTools(req *api.ResponseRequest) ([]*genai.Tool, error) {
+	if req.Tools == nil || len(req.Tools) == 0 {
+		return nil, nil
+	}
+
+	// Unmarshal to slice of tool definitions
+	var toolDefs []map[string]interface{}
+	if err := json.Unmarshal(req.Tools, &toolDefs); err != nil {
+		return nil, fmt.Errorf("unmarshal tools: %w", err)
+	}
+
+	var functionDeclarations []*genai.FunctionDeclaration
+
+	for _, toolDef := range toolDefs {
+		// Extract function details
+		// Support both flat format (name/description/parameters at top level)
+		// and nested format (under "function" key)
+		var name, description string
+		var parameters interface{}
+
+		if functionData, ok := toolDef["function"].(map[string]interface{}); ok {
+			// Nested format: {"type": "function", "function": {...}}
+			name, _ = functionData["name"].(string)
+			description, _ = functionData["description"].(string)
+			parameters = functionData["parameters"]
+		} else {
+			// Flat format: {"type": "function", "name": "...", ...}
+			name, _ = toolDef["name"].(string)
+			description, _ = toolDef["description"].(string)
+			parameters = toolDef["parameters"]
+		}
+
+		if name == "" {
+			continue
+		}
+
+		// Create function declaration
+		funcDecl := &genai.FunctionDeclaration{
+			Name:        name,
+			Description: description,
+		}
+
+		// Google accepts parameters as raw JSON schema
+		if parameters != nil {
+			funcDecl.ParametersJsonSchema = parameters
+		}
+
+		functionDeclarations = append(functionDeclarations, funcDecl)
+	}
+
+	// Return single Tool with all function declarations
+	if len(functionDeclarations) > 0 {
+		return []*genai.Tool{{FunctionDeclarations: functionDeclarations}}, nil
+	}
+
+	return nil, nil
+}
+
+// parseToolChoice converts req.ToolChoice to Google's ToolConfig with FunctionCallingConfig.
+func parseToolChoice(req *api.ResponseRequest) (*genai.ToolConfig, error) {
+	if req.ToolChoice == nil || len(req.ToolChoice) == 0 {
+		return nil, nil
+	}
+
+	var choice interface{}
+	if err := json.Unmarshal(req.ToolChoice, &choice); err != nil {
+		return nil, fmt.Errorf("unmarshal tool_choice: %w", err)
+	}
+
+	config := &genai.ToolConfig{
+		FunctionCallingConfig: &genai.FunctionCallingConfig{},
+	}
+
+	// Handle string values: "auto", "none", "required"/"any"
+	if str, ok := choice.(string); ok {
+		switch str {
+		case "auto":
+			config.FunctionCallingConfig.Mode = genai.FunctionCallingConfigModeAuto
+		case "none":
+			config.FunctionCallingConfig.Mode = genai.FunctionCallingConfigModeNone
+		case "required", "any":
+			config.FunctionCallingConfig.Mode = genai.FunctionCallingConfigModeAny
+		default:
+			return nil, fmt.Errorf("unknown tool_choice string: %s", str)
+		}
+		return config, nil
+	}
+
+	// Handle object format: {"type": "function", "function": {"name": "..."}}
+	if obj, ok := choice.(map[string]interface{}); ok {
+		if typeVal, ok := obj["type"].(string); ok && typeVal == "function" {
+			config.FunctionCallingConfig.Mode = genai.FunctionCallingConfigModeAny
+			if funcObj, ok := obj["function"].(map[string]interface{}); ok {
+				if name, ok := funcObj["name"].(string); ok {
+					config.FunctionCallingConfig.AllowedFunctionNames = []string{name}
+				}
+			}
+			return config, nil
+		}
+	}
+
+	return nil, fmt.Errorf("unsupported tool_choice format")
+}
+
+// extractToolCalls extracts tool calls from Google's response format to generic api.ToolCall slice.
+func extractToolCalls(resp *genai.GenerateContentResponse) []api.ToolCall {
+	var toolCalls []api.ToolCall
+
+	for _, candidate := range resp.Candidates {
+		if candidate.Content == nil {
+			continue
+		}
+
+		for _, part := range candidate.Content.Parts {
+			if part == nil || part.FunctionCall == nil {
+				continue
+			}
+
+			// Extract function call details
+			fc := part.FunctionCall
+
+			// Marshal arguments to JSON string
+			var argsJSON string
+			if fc.Args != nil {
+				argsBytes, err := json.Marshal(fc.Args)
+				if err == nil {
+					argsJSON = string(argsBytes)
+				} else {
+					// Fallback to empty object
+					argsJSON = "{}"
+				}
+			} else {
+				argsJSON = "{}"
+			}
+
+			// Generate ID if Google doesn't provide one
+			callID := fc.ID
+			if callID == "" {
+				callID = fmt.Sprintf("call_%s", generateRandomID())
+			}
+
+			toolCalls = append(toolCalls, api.ToolCall{
+				ID:        callID,
+				Name:      fc.Name,
+				Arguments: argsJSON,
+			})
+		}
+	}
+
+	return toolCalls
+}
+
+// extractToolCallDelta extracts streaming tool call information from response parts.
+func extractToolCallDelta(part *genai.Part, index int) *api.ToolCallDelta {
+	if part == nil || part.FunctionCall == nil {
+		return nil
+	}
+
+	fc := part.FunctionCall
+
+	// Marshal arguments to JSON string
+	var argsJSON string
+	if fc.Args != nil {
+		argsBytes, err := json.Marshal(fc.Args)
+		if err == nil {
+			argsJSON = string(argsBytes)
+		} else {
+			argsJSON = "{}"
+		}
+	} else {
+		argsJSON = "{}"
+	}
+
+	// Generate ID if Google doesn't provide one
+	callID := fc.ID
+	if callID == "" {
+		callID = fmt.Sprintf("call_%s", generateRandomID())
+	}
+
+	return &api.ToolCallDelta{
+		Index:     index,
+		ID:        callID,
+		Name:      fc.Name,
+		Arguments: argsJSON,
+	}
+}
+
+// generateRandomID generates a random alphanumeric ID
+func generateRandomID() string {
+	const charset = "abcdefghijklmnopqrstuvwxyz0123456789"
+	const length = 24
+	rng := rand.New(rand.NewSource(time.Now().UnixNano()))
+	b := make([]byte, length)
+	for i := range b {
+		b[i] = charset[rng.Intn(len(charset))]
+	}
+	return string(b)
+}
--- a/internal/providers/google/google.go
+++ b/internal/providers/google/google.go
@@ -2,13 +2,14 @@ package google

 import (
 	"context"
+	"encoding/json"
 	"fmt"

 	"github.com/google/uuid"
 	"google.golang.org/genai"

-	"github.com/yourusername/go-llm-gateway/internal/api"
-	"github.com/yourusername/go-llm-gateway/internal/config"
+	"github.com/ajac-zero/latticelm/internal/api"
+	"github.com/ajac-zero/latticelm/internal/config"
 )

 const Name = "google"
@@ -19,7 +20,7 @@ type Provider struct {
 	client *genai.Client
 }

-// New constructs a Provider using the provided configuration.
+// New constructs a Provider using the Google AI API with API key authentication.
 func New(cfg config.ProviderConfig) *Provider {
 	var client *genai.Client
 	if cfg.APIKey != "" {
@@ -38,13 +39,36 @@ func New(cfg config.ProviderConfig) *Provider {
 	}
 }

+// NewVertexAI constructs a Provider targeting Vertex AI.
+// Vertex AI uses the same genai SDK but with GCP project/location configuration
+// and Application Default Credentials (ADC) or service account authentication.
+func NewVertexAI(vertexCfg config.VertexAIConfig) *Provider {
+	var client *genai.Client
+	if vertexCfg.Project != "" && vertexCfg.Location != "" {
+		var err error
+		client, err = genai.NewClient(context.Background(), &genai.ClientConfig{
+			Project:  vertexCfg.Project,
+			Location: vertexCfg.Location,
+			Backend:  genai.BackendVertexAI,
+		})
+		if err != nil {
+			// Log error but don't fail construction - will fail on Generate
+			fmt.Printf("warning: failed to create vertex ai client: %v\n", err)
+		}
+	}
+	return &Provider{
+		cfg: config.ProviderConfig{
+			// Vertex AI doesn't use API key, but set empty for consistency
+			APIKey: "",
+		},
+		client: client,
+	}
+}
+
 func (p *Provider) Name() string { return Name }

 // Generate routes the request to Gemini and returns a ProviderResult.
 func (p *Provider) Generate(ctx context.Context, messages []api.Message, req *api.ResponseRequest) (*api.ProviderResult, error) {
-	if p.cfg.APIKey == "" {
-		return nil, fmt.Errorf("google api key missing")
-	}
 	if p.client == nil {
 		return nil, fmt.Errorf("google client not initialized")
 	}
@@ -53,7 +77,27 @@ func (p *Provider) Generate(ctx context.Context, messages []api.Message, req *ap

 	contents, systemText := convertMessages(messages)

-	config := buildConfig(systemText, req)
+	// Parse tools if present
+	var tools []*genai.Tool
+	if req.Tools != nil && len(req.Tools) > 0 {
+		var err error
+		tools, err = parseTools(req)
+		if err != nil {
+			return nil, fmt.Errorf("parse tools: %w", err)
+		}
+	}
+
+	// Parse tool_choice if present
+	var toolConfig *genai.ToolConfig
+	if req.ToolChoice != nil && len(req.ToolChoice) > 0 {
+		var err error
+		toolConfig, err = parseToolChoice(req)
+		if err != nil {
+			return nil, fmt.Errorf("parse tool_choice: %w", err)
+		}
+	}
+
+	config := buildConfig(systemText, req, tools, toolConfig)

 	resp, err := p.client.Models.GenerateContent(ctx, model, contents, config)
 	if err != nil {
@@ -69,6 +113,11 @@ func (p *Provider) Generate(ctx context.Context, messages []api.Message, req *ap
 		}
 	}

+	var toolCalls []api.ToolCall
+	if len(resp.Candidates) > 0 {
+		toolCalls = extractToolCalls(resp)
+	}
+
 	var inputTokens, outputTokens int
 	if resp.UsageMetadata != nil {
 		inputTokens = int(resp.UsageMetadata.PromptTokenCount)
@@ -76,9 +125,10 @@ func (p *Provider) Generate(ctx context.Context, messages []api.Message, req *ap
 	}

 	return &api.ProviderResult{
-		ID:    uuid.NewString(),
-		Model: model,
-		Text:  text,
+		ID:        uuid.NewString(),
+		Model:     model,
+		Text:      text,
+		ToolCalls: toolCalls,
 		Usage: api.Usage{
 			InputTokens:  inputTokens,
 			OutputTokens: outputTokens,
@@ -96,10 +146,6 @@ func (p *Provider) GenerateStream(ctx context.Context, messages []api.Message, r
 		defer close(deltaChan)
 		defer close(errChan)

-		if p.cfg.APIKey == "" {
-			errChan <- fmt.Errorf("google api key missing")
-			return
-		}
 		if p.client == nil {
 			errChan <- fmt.Errorf("google client not initialized")
 			return
@@ -109,7 +155,29 @@ func (p *Provider) GenerateStream(ctx context.Context, messages []api.Message, r

 		contents, systemText := convertMessages(messages)

-		config := buildConfig(systemText, req)
+		// Parse tools if present
+		var tools []*genai.Tool
+		if req.Tools != nil && len(req.Tools) > 0 {
+			var err error
+			tools, err = parseTools(req)
+			if err != nil {
+				errChan <- fmt.Errorf("parse tools: %w", err)
+				return
+			}
+		}
+
+		// Parse tool_choice if present
+		var toolConfig *genai.ToolConfig
+		if req.ToolChoice != nil && len(req.ToolChoice) > 0 {
+			var err error
+			toolConfig, err = parseToolChoice(req)
+			if err != nil {
+				errChan <- fmt.Errorf("parse tool_choice: %w", err)
+				return
+			}
+		}
+
+		config := buildConfig(systemText, req, tools, toolConfig)

 		stream := p.client.Models.GenerateContentStream(ctx, model, contents, config)

@@ -119,21 +187,32 @@ func (p *Provider) GenerateStream(ctx context.Context, messages []api.Message, r
 				return
 			}

-			var text string
 			if len(resp.Candidates) > 0 && resp.Candidates[0].Content != nil {
-				for _, part := range resp.Candidates[0].Content.Parts {
+				for partIndex, part := range resp.Candidates[0].Content.Parts {
 					if part != nil {
-						text += part.Text
-					}
-				}
-			}
+						// Handle text content
+						if part.Text != "" {
+							select {
+							case deltaChan <- &api.ProviderStreamDelta{Text: part.Text}:
+							case <-ctx.Done():
+								errChan <- ctx.Err()
+								return
+							}
+						}

-			if text != "" {
-				select {
-				case deltaChan <- &api.ProviderStreamDelta{Text: text}:
-				case <-ctx.Done():
-					errChan <- ctx.Err()
-					return
+						// Handle tool call content
+						if part.FunctionCall != nil {
+							delta := extractToolCallDelta(part, partIndex)
+							if delta != nil {
+								select {
+								case deltaChan <- &api.ProviderStreamDelta{ToolCallDelta: delta}:
+								case <-ctx.Done():
+									errChan <- ctx.Err()
+									return
+								}
+							}
+						}
+					}
 				}
 			}
 		}
@@ -163,6 +242,39 @@ func convertMessages(messages []api.Message) ([]*genai.Content, string) {
 			continue
 		}

+		if msg.Role == "tool" {
+			// Tool results are sent as FunctionResponse in user role message
+			var output string
+			for _, block := range msg.Content {
+				if block.Type == "input_text" || block.Type == "output_text" {
+					output += block.Text
+				}
+			}
+
+			// Parse output as JSON map, or wrap in {"output": "..."} if not JSON
+			var responseMap map[string]any
+			if err := json.Unmarshal([]byte(output), &responseMap); err != nil {
+				// Not JSON, wrap it
+				responseMap = map[string]any{"output": output}
+			}
+
+			// Create FunctionResponse part with CallID from message
+			part := &genai.Part{
+				FunctionResponse: &genai.FunctionResponse{
+					ID:       msg.CallID,
+					Name:     "", // Name is optional for responses
+					Response: responseMap,
+				},
+			}
+
+			// Add to user role message
+			contents = append(contents, &genai.Content{
+				Role:  "user",
+				Parts: []*genai.Part{part},
+			})
+			continue
+		}
+
 		var parts []*genai.Part
 		for _, block := range msg.Content {
 			if block.Type == "input_text" || block.Type == "output_text" {
@@ -185,10 +297,10 @@ func convertMessages(messages []api.Message) ([]*genai.Content, string) {
 }

 // buildConfig constructs a GenerateContentConfig from system text and request params.
-func buildConfig(systemText string, req *api.ResponseRequest) *genai.GenerateContentConfig {
+func buildConfig(systemText string, req *api.ResponseRequest, tools []*genai.Tool, toolConfig *genai.ToolConfig) *genai.GenerateContentConfig {
 	var cfg *genai.GenerateContentConfig

-	needsCfg := systemText != "" || req.MaxOutputTokens != nil || req.Temperature != nil || req.TopP != nil
+	needsCfg := systemText != "" || req.MaxOutputTokens != nil || req.Temperature != nil || req.TopP != nil || tools != nil || toolConfig != nil
 	if !needsCfg {
 		return nil
 	}
@@ -215,6 +327,14 @@ func buildConfig(systemText string, req *api.ResponseRequest) *genai.GenerateCon
 		cfg.TopP = &tp
 	}

+	if tools != nil {
+		cfg.Tools = tools
+	}
+
+	if toolConfig != nil {
+		cfg.ToolConfig = toolConfig
+	}
+
 	return cfg
 }

--- a/internal/providers/openai/convert.go
+++ b/internal/providers/openai/convert.go
@@ -0,0 +1,117 @@
+package openai
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/ajac-zero/latticelm/internal/api"
+	"github.com/openai/openai-go/v3"
+	"github.com/openai/openai-go/v3/shared"
+)
+
+// parseTools converts Open Responses tools to OpenAI format
+func parseTools(req *api.ResponseRequest) ([]openai.ChatCompletionToolUnionParam, error) {
+	if req.Tools == nil || len(req.Tools) == 0 {
+		return nil, nil
+	}
+
+	var toolDefs []map[string]interface{}
+	if err := json.Unmarshal(req.Tools, &toolDefs); err != nil {
+		return nil, fmt.Errorf("unmarshal tools: %w", err)
+	}
+
+	var tools []openai.ChatCompletionToolUnionParam
+	for _, td := range toolDefs {
+		// Convert Open Responses tool to OpenAI ChatCompletionFunctionToolParam
+		// Extract: name, description, parameters
+		name, _ := td["name"].(string)
+		desc, _ := td["description"].(string)
+		params, _ := td["parameters"].(map[string]interface{})
+
+		funcDef := shared.FunctionDefinitionParam{
+			Name: name,
+		}
+
+		if desc != "" {
+			funcDef.Description = openai.String(desc)
+		}
+
+		if params != nil {
+			funcDef.Parameters = shared.FunctionParameters(params)
+		}
+
+		tools = append(tools, openai.ChatCompletionFunctionTool(funcDef))
+	}
+
+	return tools, nil
+}
+
+// parseToolChoice converts Open Responses tool_choice to OpenAI format
+func parseToolChoice(req *api.ResponseRequest) (openai.ChatCompletionToolChoiceOptionUnionParam, error) {
+	var result openai.ChatCompletionToolChoiceOptionUnionParam
+
+	if req.ToolChoice == nil || len(req.ToolChoice) == 0 {
+		return result, nil
+	}
+
+	var choice interface{}
+	if err := json.Unmarshal(req.ToolChoice, &choice); err != nil {
+		return result, fmt.Errorf("unmarshal tool_choice: %w", err)
+	}
+
+	// Handle string values: "auto", "none", "required"
+	if str, ok := choice.(string); ok {
+		result.OfAuto = openai.String(str)
+		return result, nil
+	}
+
+	// Handle specific function selection: {"type": "function", "function": {"name": "..."}}
+	if obj, ok := choice.(map[string]interface{}); ok {
+		funcObj, _ := obj["function"].(map[string]interface{})
+		name, _ := funcObj["name"].(string)
+
+		return openai.ToolChoiceOptionFunctionToolChoice(
+			openai.ChatCompletionNamedToolChoiceFunctionParam{
+				Name: name,
+			},
+		), nil
+	}
+
+	return result, fmt.Errorf("invalid tool_choice format")
+}
+
+// extractToolCalls converts OpenAI tool calls to api.ToolCall
+func extractToolCalls(message openai.ChatCompletionMessage) []api.ToolCall {
+	if len(message.ToolCalls) == 0 {
+		return nil
+	}
+
+	var toolCalls []api.ToolCall
+	for _, tc := range message.ToolCalls {
+		toolCalls = append(toolCalls, api.ToolCall{
+			ID:        tc.ID,
+			Name:      tc.Function.Name,
+			Arguments: tc.Function.Arguments,
+		})
+	}
+	return toolCalls
+}
+
+// extractToolCallDelta extracts tool call delta from streaming chunk choice
+func extractToolCallDelta(choice openai.ChatCompletionChunkChoice) *api.ToolCallDelta {
+	if len(choice.Delta.ToolCalls) == 0 {
+		return nil
+	}
+
+	// OpenAI sends tool calls with index in the delta
+	for _, tc := range choice.Delta.ToolCalls {
+		return &api.ToolCallDelta{
+			Index:     int(tc.Index),
+			ID:        tc.ID,
+			Name:      tc.Function.Name,
+			Arguments: tc.Function.Arguments,
+		}
+	}
+
+	return nil
+}
--- a/internal/providers/openai/openai.go
+++ b/internal/providers/openai/openai.go
@@ -4,12 +4,12 @@ import (
 	"context"
 	"fmt"

-	"github.com/openai/openai-go"
-	"github.com/openai/openai-go/azure"
-	"github.com/openai/openai-go/option"
+	"github.com/openai/openai-go/v3"
+	"github.com/openai/openai-go/v3/azure"
+	"github.com/openai/openai-go/v3/option"

-	"github.com/yourusername/go-llm-gateway/internal/api"
-	"github.com/yourusername/go-llm-gateway/internal/config"
+	"github.com/ajac-zero/latticelm/internal/api"
+	"github.com/ajac-zero/latticelm/internal/config"
 )

 const Name = "openai"
@@ -91,6 +91,8 @@ func (p *Provider) Generate(ctx context.Context, messages []api.Message, req *ap
 			oaiMessages = append(oaiMessages, openai.SystemMessage(content))
 		case "developer":
 			oaiMessages = append(oaiMessages, openai.SystemMessage(content))
+		case "tool":
+			oaiMessages = append(oaiMessages, openai.ToolMessage(content, msg.CallID))
 		}
 	}

@@ -108,6 +110,29 @@ func (p *Provider) Generate(ctx context.Context, messages []api.Message, req *ap
 		params.TopP = openai.Float(*req.TopP)
 	}

+	// Add tools if present
+	if req.Tools != nil && len(req.Tools) > 0 {
+		tools, err := parseTools(req)
+		if err != nil {
+			return nil, fmt.Errorf("parse tools: %w", err)
+		}
+		params.Tools = tools
+	}
+
+	// Add tool_choice if present
+	if req.ToolChoice != nil && len(req.ToolChoice) > 0 {
+		toolChoice, err := parseToolChoice(req)
+		if err != nil {
+			return nil, fmt.Errorf("parse tool_choice: %w", err)
+		}
+		params.ToolChoice = toolChoice
+	}
+
+	// Add parallel_tool_calls if specified
+	if req.ParallelToolCalls != nil {
+		params.ParallelToolCalls = openai.Bool(*req.ParallelToolCalls)
+	}
+
 	// Call OpenAI API
 	resp, err := p.client.Chat.Completions.New(ctx, params)
 	if err != nil {
@@ -115,14 +140,20 @@ func (p *Provider) Generate(ctx context.Context, messages []api.Message, req *ap
 	}

 	var combinedText string
+	var toolCalls []api.ToolCall
+
 	for _, choice := range resp.Choices {
 		combinedText += choice.Message.Content
+		if len(choice.Message.ToolCalls) > 0 {
+			toolCalls = append(toolCalls, extractToolCalls(choice.Message)...)
+		}
 	}

 	return &api.ProviderResult{
-		ID:    resp.ID,
-		Model: resp.Model,
-		Text:  combinedText,
+		ID:        resp.ID,
+		Model:     resp.Model,
+		Text:      combinedText,
+		ToolCalls: toolCalls,
 		Usage: api.Usage{
 			InputTokens:  int(resp.Usage.PromptTokens),
 			OutputTokens: int(resp.Usage.CompletionTokens),
@@ -168,6 +199,8 @@ func (p *Provider) GenerateStream(ctx context.Context, messages []api.Message, r
 				oaiMessages = append(oaiMessages, openai.SystemMessage(content))
 			case "developer":
 				oaiMessages = append(oaiMessages, openai.SystemMessage(content))
+			case "tool":
+				oaiMessages = append(oaiMessages, openai.ToolMessage(content, msg.CallID))
 			}
 		}

@@ -185,6 +218,31 @@ func (p *Provider) GenerateStream(ctx context.Context, messages []api.Message, r
 			params.TopP = openai.Float(*req.TopP)
 		}

+		// Add tools if present
+		if req.Tools != nil && len(req.Tools) > 0 {
+			tools, err := parseTools(req)
+			if err != nil {
+				errChan <- fmt.Errorf("parse tools: %w", err)
+				return
+			}
+			params.Tools = tools
+		}
+
+		// Add tool_choice if present
+		if req.ToolChoice != nil && len(req.ToolChoice) > 0 {
+			toolChoice, err := parseToolChoice(req)
+			if err != nil {
+				errChan <- fmt.Errorf("parse tool_choice: %w", err)
+				return
+			}
+			params.ToolChoice = toolChoice
+		}
+
+		// Add parallel_tool_calls if specified
+		if req.ParallelToolCalls != nil {
+			params.ParallelToolCalls = openai.Bool(*req.ParallelToolCalls)
+		}
+
 		// Create streaming request
 		stream := p.client.Chat.Completions.NewStreaming(ctx, params)

@@ -193,19 +251,35 @@ func (p *Provider) GenerateStream(ctx context.Context, messages []api.Message, r
 			chunk := stream.Current()

 			for _, choice := range chunk.Choices {
-				if choice.Delta.Content == "" {
-					continue
+				// Handle text content
+				if choice.Delta.Content != "" {
+					select {
+					case deltaChan <- &api.ProviderStreamDelta{
+						ID:    chunk.ID,
+						Model: chunk.Model,
+						Text:  choice.Delta.Content,
+					}:
+					case <-ctx.Done():
+						errChan <- ctx.Err()
+						return
+					}
 				}

-				select {
-				case deltaChan <- &api.ProviderStreamDelta{
-					ID:    chunk.ID,
-					Model: chunk.Model,
-					Text:  choice.Delta.Content,
-				}:
-				case <-ctx.Done():
-					errChan <- ctx.Err()
-					return
+				// Handle tool call deltas
+				if len(choice.Delta.ToolCalls) > 0 {
+					delta := extractToolCallDelta(choice)
+					if delta != nil {
+						select {
+						case deltaChan <- &api.ProviderStreamDelta{
+							ID:            chunk.ID,
+							Model:         chunk.Model,
+							ToolCallDelta: delta,
+						}:
+						case <-ctx.Done():
+							errChan <- ctx.Err()
+							return
+						}
+					}
 				}
 			}
 		}
--- a/internal/providers/providers.go
+++ b/internal/providers/providers.go
@@ -4,11 +4,11 @@ import (
 	"context"
 	"fmt"

-	"github.com/yourusername/go-llm-gateway/internal/api"
-	"github.com/yourusername/go-llm-gateway/internal/config"
-	anthropicprovider "github.com/yourusername/go-llm-gateway/internal/providers/anthropic"
-	googleprovider "github.com/yourusername/go-llm-gateway/internal/providers/google"
-	openaiprovider "github.com/yourusername/go-llm-gateway/internal/providers/openai"
+	"github.com/ajac-zero/latticelm/internal/api"
+	"github.com/ajac-zero/latticelm/internal/config"
+	anthropicprovider "github.com/ajac-zero/latticelm/internal/providers/anthropic"
+	googleprovider "github.com/ajac-zero/latticelm/internal/providers/google"
+	openaiprovider "github.com/ajac-zero/latticelm/internal/providers/openai"
 )

 // Provider represents a unified interface that each LLM provider must implement.
@@ -60,7 +60,8 @@ func NewRegistry(entries map[string]config.ProviderEntry, models []config.ModelE
 }

 func buildProvider(entry config.ProviderEntry) (Provider, error) {
-	if entry.APIKey == "" {
+	// Vertex AI doesn't require APIKey, so check for it separately
+	if entry.Type != "vertexai" && entry.APIKey == "" {
 		return nil, nil
 	}

@@ -97,6 +98,14 @@ func buildProvider(entry config.ProviderEntry) (Provider, error) {
 			APIKey:   entry.APIKey,
 			Endpoint: entry.Endpoint,
 		}), nil
+	case "vertexai":
+		if entry.Project == "" || entry.Location == "" {
+			return nil, fmt.Errorf("project and location are required for vertexai")
+		}
+		return googleprovider.NewVertexAI(config.VertexAIConfig{
+			Project:  entry.Project,
+			Location: entry.Location,
+		}), nil
 	default:
 		return nil, fmt.Errorf("unknown provider type %q", entry.Type)
 	}
--- a/internal/server/server.go
+++ b/internal/server/server.go
@@ -10,9 +10,9 @@ import (

 	"github.com/google/uuid"

-	"github.com/yourusername/go-llm-gateway/internal/api"
-	"github.com/yourusername/go-llm-gateway/internal/conversation"
-	"github.com/yourusername/go-llm-gateway/internal/providers"
+	"github.com/ajac-zero/latticelm/internal/api"
+	"github.com/ajac-zero/latticelm/internal/conversation"
+	"github.com/ajac-zero/latticelm/internal/providers"
 )

 // GatewayServer hosts the Open Responses API for the gateway.
@@ -84,8 +84,13 @@ func (s *GatewayServer) handleResponses(w http.ResponseWriter, r *http.Request)
 	// Build full message history from previous conversation
 	var historyMsgs []api.Message
 	if req.PreviousResponseID != nil && *req.PreviousResponseID != "" {
-		conv, ok := s.convs.Get(*req.PreviousResponseID)
-		if !ok {
+		conv, err := s.convs.Get(*req.PreviousResponseID)
+		if err != nil {
+			s.logger.Printf("error retrieving conversation: %v", err)
+			http.Error(w, "error retrieving conversation", http.StatusInternalServerError)
+			return
+		}
+		if conv == nil {
 			http.Error(w, "conversation not found", http.StatusNotFound)
 			return
 		}
@@ -140,7 +145,10 @@ func (s *GatewayServer) handleSyncResponse(w http.ResponseWriter, r *http.Reques
 		Content: []api.ContentBlock{{Type: "output_text", Text: result.Text}},
 	}
 	allMsgs := append(storeMsgs, assistantMsg)
-	s.convs.Create(responseID, result.Model, allMsgs)
+	if _, err := s.convs.Create(responseID, result.Model, allMsgs); err != nil {
+		s.logger.Printf("error storing conversation: %v", err)
+		// Don't fail the response if storage fails
+	}

 	// Build spec-compliant response
 	resp := s.buildResponse(origReq, result, provider.Name(), responseID)
@@ -224,6 +232,17 @@ func (s *GatewayServer) handleStreamingResponse(w http.ResponseWriter, r *http.R
 	var streamErr error
 	var providerModel string

+	// Track tool calls being built
+	type toolCallBuilder struct {
+		itemID    string
+		id        string
+		name      string
+		arguments string
+	}
+	toolCallsInProgress := make(map[int]*toolCallBuilder)
+	nextOutputIdx := 0
+	textItemAdded := false
+
 loop:
 	for {
 		select {
@@ -234,7 +253,14 @@ loop:
 			if delta.Model != "" && providerModel == "" {
 				providerModel = delta.Model
 			}
+
+			// Handle text content
 			if delta.Text != "" {
+				// Add text item on first text delta
+				if !textItemAdded {
+					textItemAdded = true
+					nextOutputIdx++
+				}
 				fullText += delta.Text
 				s.sendSSE(w, flusher, &seq, "response.output_text.delta", &api.StreamEvent{
 					Type:         "response.output_text.delta",
@@ -244,6 +270,53 @@ loop:
 					Delta:        delta.Text,
 				})
 			}
+
+			// Handle tool call delta
+			if delta.ToolCallDelta != nil {
+				tc := delta.ToolCallDelta
+
+				// First chunk for this tool call index
+				if _, exists := toolCallsInProgress[tc.Index]; !exists {
+					toolItemID := generateID("item_")
+					toolOutputIdx := nextOutputIdx
+					nextOutputIdx++
+
+					// Send response.output_item.added
+					s.sendSSE(w, flusher, &seq, "response.output_item.added", &api.StreamEvent{
+						Type:        "response.output_item.added",
+						OutputIndex: &toolOutputIdx,
+						Item: &api.OutputItem{
+							ID:     toolItemID,
+							Type:   "function_call",
+							Status: "in_progress",
+							CallID: tc.ID,
+							Name:   tc.Name,
+						},
+					})
+
+					toolCallsInProgress[tc.Index] = &toolCallBuilder{
+						itemID:    toolItemID,
+						id:        tc.ID,
+						name:      tc.Name,
+						arguments: "",
+					}
+				}
+
+				// Send function_call_arguments.delta
+				if tc.Arguments != "" {
+					builder := toolCallsInProgress[tc.Index]
+					builder.arguments += tc.Arguments
+					toolOutputIdx := outputIdx + 1 + tc.Index
+
+					s.sendSSE(w, flusher, &seq, "response.function_call_arguments.delta", &api.StreamEvent{
+						Type:        "response.function_call_arguments.delta",
+						ItemID:      builder.itemID,
+						OutputIndex: &toolOutputIdx,
+						Delta:       tc.Arguments,
+					})
+				}
+			}
+
 			if delta.Done {
 				break loop
 			}
@@ -277,54 +350,108 @@ loop:
 		return
 	}

-	// response.output_text.done
-	s.sendSSE(w, flusher, &seq, "response.output_text.done", &api.StreamEvent{
-		Type:         "response.output_text.done",
-		ItemID:       itemID,
-		OutputIndex:  &outputIdx,
-		ContentIndex: &contentIdx,
-		Text:         fullText,
-	})
+	// Send done events for text output if text was added
+	if textItemAdded && fullText != "" {
+		// response.output_text.done
+		s.sendSSE(w, flusher, &seq, "response.output_text.done", &api.StreamEvent{
+			Type:         "response.output_text.done",
+			ItemID:       itemID,
+			OutputIndex:  &outputIdx,
+			ContentIndex: &contentIdx,
+			Text:         fullText,
+		})

-	// response.content_part.done
-	completedPart := &api.ContentPart{
-		Type:        "output_text",
-		Text:        fullText,
-		Annotations: []api.Annotation{},
-	}
-	s.sendSSE(w, flusher, &seq, "response.content_part.done", &api.StreamEvent{
-		Type:         "response.content_part.done",
-		ItemID:       itemID,
-		OutputIndex:  &outputIdx,
-		ContentIndex: &contentIdx,
-		Part:         completedPart,
-	})
+		// response.content_part.done
+		completedPart := &api.ContentPart{
+			Type:        "output_text",
+			Text:        fullText,
+			Annotations: []api.Annotation{},
+		}
+		s.sendSSE(w, flusher, &seq, "response.content_part.done", &api.StreamEvent{
+			Type:         "response.content_part.done",
+			ItemID:       itemID,
+			OutputIndex:  &outputIdx,
+			ContentIndex: &contentIdx,
+			Part:         completedPart,
+		})

-	// response.output_item.done
-	completedItem := &api.OutputItem{
-		ID:     itemID,
-		Type:   "message",
-		Status: "completed",
-		Role:   "assistant",
-		Content: []api.ContentPart{*completedPart},
+		// response.output_item.done
+		completedItem := &api.OutputItem{
+			ID:      itemID,
+			Type:    "message",
+			Status:  "completed",
+			Role:    "assistant",
+			Content: []api.ContentPart{*completedPart},
+		}
+		s.sendSSE(w, flusher, &seq, "response.output_item.done", &api.StreamEvent{
+			Type:        "response.output_item.done",
+			OutputIndex: &outputIdx,
+			Item:        completedItem,
+		})
+	}
+
+	// Send done events for each tool call
+	for idx, builder := range toolCallsInProgress {
+		toolOutputIdx := outputIdx + 1 + idx
+
+		s.sendSSE(w, flusher, &seq, "response.function_call_arguments.done", &api.StreamEvent{
+			Type:        "response.function_call_arguments.done",
+			ItemID:      builder.itemID,
+			OutputIndex: &toolOutputIdx,
+			Arguments:   builder.arguments,
+		})
+
+		s.sendSSE(w, flusher, &seq, "response.output_item.done", &api.StreamEvent{
+			Type:        "response.output_item.done",
+			OutputIndex: &toolOutputIdx,
+			Item: &api.OutputItem{
+				ID:        builder.itemID,
+				Type:      "function_call",
+				Status:    "completed",
+				CallID:    builder.id,
+				Name:      builder.name,
+				Arguments: builder.arguments,
+			},
+		})
 	}
-	s.sendSSE(w, flusher, &seq, "response.output_item.done", &api.StreamEvent{
-		Type:        "response.output_item.done",
-		OutputIndex: &outputIdx,
-		Item:        completedItem,
-	})

 	// Build final completed response
 	model := origReq.Model
 	if providerModel != "" {
 		model = providerModel
 	}
+
+	// Collect tool calls for result
+	var toolCalls []api.ToolCall
+	for _, builder := range toolCallsInProgress {
+		toolCalls = append(toolCalls, api.ToolCall{
+			ID:        builder.id,
+			Name:      builder.name,
+			Arguments: builder.arguments,
+		})
+	}
+
 	finalResult := &api.ProviderResult{
-		Model: model,
-		Text:  fullText,
+		Model:     model,
+		Text:      fullText,
+		ToolCalls: toolCalls,
 	}
 	completedResp := s.buildResponse(origReq, finalResult, provider.Name(), responseID)
-	completedResp.Output[0].ID = itemID
+
+	// Update item IDs to match what we sent during streaming
+	if textItemAdded && len(completedResp.Output) > 0 {
+		completedResp.Output[0].ID = itemID
+	}
+	for idx, builder := range toolCallsInProgress {
+		// Find the corresponding output item
+		for i := range completedResp.Output {
+			if completedResp.Output[i].Type == "function_call" && completedResp.Output[i].CallID == builder.id {
+				completedResp.Output[i].ID = builder.itemID
+				break
+			}
+		}
+		_ = idx // unused
+	}

 	// response.completed
 	s.sendSSE(w, flusher, &seq, "response.completed", &api.StreamEvent{
@@ -339,7 +466,10 @@ loop:
 			Content: []api.ContentBlock{{Type: "output_text", Text: fullText}},
 		}
 		allMsgs := append(storeMsgs, assistantMsg)
-		s.convs.Create(responseID, model, allMsgs)
+		if _, err := s.convs.Create(responseID, model, allMsgs); err != nil {
+			s.logger.Printf("error storing conversation: %v", err)
+			// Don't fail the response if storage fails
+		}
 	}
 }

@@ -363,18 +493,34 @@ func (s *GatewayServer) buildResponse(req *api.ResponseRequest, result *api.Prov
 		model = req.Model
 	}

-	// Build output item
-	itemID := generateID("msg_")
-	outputItem := api.OutputItem{
-		ID:     itemID,
-		Type:   "message",
-		Status: "completed",
-		Role:   "assistant",
-		Content: []api.ContentPart{{
-			Type:        "output_text",
-			Text:        result.Text,
-			Annotations: []api.Annotation{},
-		}},
+	// Build output items array
+	outputItems := []api.OutputItem{}
+
+	// Add message item if there's text
+	if result.Text != "" {
+		outputItems = append(outputItems, api.OutputItem{
+			ID:     generateID("msg_"),
+			Type:   "message",
+			Status: "completed",
+			Role:   "assistant",
+			Content: []api.ContentPart{{
+				Type:        "output_text",
+				Text:        result.Text,
+				Annotations: []api.Annotation{},
+			}},
+		})
+	}
+
+	// Add function_call items
+	for _, tc := range result.ToolCalls {
+		outputItems = append(outputItems, api.OutputItem{
+			ID:        generateID("item_"),
+			Type:      "function_call",
+			Status:    "completed",
+			CallID:    tc.ID,
+			Name:      tc.Name,
+			Arguments: tc.Arguments,
+		})
 	}

 	// Echo back request params with defaults
@@ -454,7 +600,7 @@ func (s *GatewayServer) buildResponse(req *api.ResponseRequest, result *api.Prov
 		Model:              model,
 		PreviousResponseID: req.PreviousResponseID,
 		Instructions:       req.Instructions,
-		Output:             []api.OutputItem{outputItem},
+		Output:             outputItems,
 		Error:              nil,
 		Tools:              tools,
 		ToolChoice:         toolChoice,
--- a/scripts/chat.py
+++ b/scripts/chat.py
@@ -3,12 +3,12 @@
 # requires-python = ">=3.11"
 # dependencies = [
 #     "rich>=13.7.0",
-#     "httpx>=0.27.0",
+#     "openai>=1.0.0",
 # ]
 # ///

 """
-Terminal chat interface for go-llm-gateway.
+Terminal chat interface for latticelm.

 Usage:
    python chat.py
@@ -18,11 +18,10 @@ Usage:
 """

 import argparse
-import json
 import sys
 from typing import Optional

-import httpx
+from openai import OpenAI, APIStatusError
 from rich.console import Console
 from rich.live import Live
 from rich.markdown import Markdown
@@ -34,16 +33,13 @@ from rich.table import Table
 class ChatClient:
    def __init__(self, base_url: str, token: Optional[str] = None):
        self.base_url = base_url.rstrip("/")
-        self.token = token
+        self.client = OpenAI(
+            base_url=f"{self.base_url}/v1",
+            api_key=token or "no-key",
+        )
        self.messages = []
        self.console = Console()
    
-    def _headers(self) -> dict:
-        headers = {"Content-Type": "application/json"}
-        if self.token:
-            headers["Authorization"] = f"Bearer {self.token}"
-        return headers
-    
    def chat(self, user_message: str, model: str, stream: bool = True):
        """Send a chat message and get response."""
        # Add user message to history
@@ -52,35 +48,20 @@ class ChatClient:
            "content": [{"type": "input_text", "text": user_message}]
        })
        
-        payload = {
-            "model": model,
-            "input": self.messages,
-            "stream": stream
-        }
-        
        if stream:
-            return self._stream_response(payload, model)
+            return self._stream_response(model)
        else:
-            return self._sync_response(payload, model)
+            return self._sync_response(model)
    
-    def _sync_response(self, payload: dict, model: str) -> str:
+    def _sync_response(self, model: str) -> str:
        """Non-streaming response."""
        with self.console.status(f"[bold blue]Thinking ({model})..."):
-            resp = httpx.post(
-                f"{self.base_url}/v1/responses",
-                json=payload,
-                headers=self._headers(),
-                timeout=60.0
+            response = self.client.responses.create(
+                model=model,
+                input=self.messages,
            )
-            resp.raise_for_status()
        
-        data = resp.json()
-        assistant_text = ""
-        
-        for msg in data.get("output", []):
-            for block in msg.get("content", []):
-                if block.get("type") == "output_text":
-                    assistant_text += block.get("text", "")
+        assistant_text = response.output_text
        
        # Add to history
        self.messages.append({
@@ -90,40 +71,19 @@ class ChatClient:
        
        return assistant_text
    
-    def _stream_response(self, payload: dict, model: str) -> str:
+    def _stream_response(self, model: str) -> str:
        """Streaming response with live rendering."""
        assistant_text = ""
        
-        with httpx.stream(
-            "POST",
-            f"{self.base_url}/v1/responses",
-            json=payload,
-            headers=self._headers(),
-            timeout=60.0
-        ) as resp:
-            resp.raise_for_status()
-            
-            with Live(console=self.console, refresh_per_second=10) as live:
-                for line in resp.iter_lines():
-                    if not line.startswith("data: "):
-                        continue
-                    
-                    data_str = line[6:]  # Remove "data: " prefix
-                    
-                    try:
-                        chunk = json.loads(data_str)
-                    except json.JSONDecodeError:
-                        continue
-                    
-                    if chunk.get("done"):
-                        break
-                    
-                    delta = chunk.get("delta", {})
-                    for block in delta.get("content", []):
-                        if block.get("type") == "output_text":
-                            assistant_text += block.get("text", "")
-                    
-                    # Render markdown in real-time
+        with Live(console=self.console, refresh_per_second=10) as live:
+            stream = self.client.responses.create(
+                model=model,
+                input=self.messages,
+                stream=True,
+            )
+            for event in stream:
+                if event.type == "response.output_text.delta":
+                    assistant_text += event.delta
                    live.update(Markdown(assistant_text))
        
        # Add to history
@@ -139,43 +99,56 @@ class ChatClient:
        self.messages = []


-def print_models_table(base_url: str, headers: dict):
+def print_models_table(client: OpenAI):
    """Fetch and print available models from the gateway."""
    console = Console()
    try:
-        resp = httpx.get(f"{base_url}/v1/models", headers=headers, timeout=10)
-        resp.raise_for_status()
-        data = resp.json().get("data", [])
+        models = client.models.list()
    except Exception as e:
        console.print(f"[red]Failed to fetch models: {e}[/red]")
        return

    table = Table(title="Available Models", show_header=True, header_style="bold magenta")
-    table.add_column("Provider", style="cyan")
+    table.add_column("Owner", style="cyan")
    table.add_column("Model ID", style="green")

-    for model in data:
-        table.add_row(model.get("provider", ""), model.get("id", ""))
+    for model in models:
+        table.add_row(model.owned_by, model.id)

    console.print(table)


 def main():
-    parser = argparse.ArgumentParser(description="Chat with go-llm-gateway")
+    parser = argparse.ArgumentParser(description="Chat with latticelm")
    parser.add_argument("--url", default="http://localhost:8080", help="Gateway URL")
-    parser.add_argument("--model", default="gemini-2.0-flash-exp", help="Model to use")
+    parser.add_argument("--model", default=None, help="Model to use (defaults to first available)")
    parser.add_argument("--token", help="Auth token (Bearer)")
    parser.add_argument("--no-stream", action="store_true", help="Disable streaming")
    args = parser.parse_args()
    
    console = Console()
    client = ChatClient(args.url, args.token)
-    current_model = args.model
+    
+    # Fetch available models and select default
+    try:
+        available_models = list(client.client.models.list())
+    except Exception as e:
+        console.print(f"[bold red]Failed to connect to gateway:[/bold red] {e}")
+        sys.exit(1)
+    
+    if not available_models:
+        console.print("[bold red]Error:[/bold red] No models are configured on the gateway.")
+        sys.exit(1)
+    
+    if args.model:
+        current_model = args.model
+    else:
+        current_model = available_models[0].id
    stream_enabled = not args.no_stream
    
    # Welcome banner
    console.print(Panel.fit(
-        "[bold cyan]go-llm-gateway Chat Interface[/bold cyan]\n"
+        "[bold cyan]latticelm Chat Interface[/bold cyan]\n"
        f"Connected to: [green]{args.url}[/green]\n"
        f"Model: [yellow]{current_model}[/yellow]\n"
        f"Streaming: [{'green' if stream_enabled else 'red'}]{stream_enabled}[/]\n\n"
@@ -230,7 +203,7 @@ def main():
                    ))
                
                elif cmd == "/models":
-                    print_models_table(args.url, client._headers())
+                    print_models_table(client.client)
                
                elif cmd == "/model":
                    if len(cmd_parts) < 2:
@@ -265,8 +238,8 @@ def main():
                    # For non-streaming, render markdown
                    console.print(Markdown(response))
                
-            except httpx.HTTPStatusError as e:
-                console.print(f"[bold red]Error {e.response.status_code}:[/bold red] {e.response.text}")
+            except APIStatusError as e:
+                console.print(f"[bold red]Error {e.status_code}:[/bold red] {e.message}")
            except Exception as e:
                console.print(f"[bold red]Error:[/bold red] {e}")
        
--- a/tests/bin/compliance-test.ts
+++ b/tests/bin/compliance-test.ts
@@ -0,0 +1,270 @@
+import {
+  testTemplates,
+  runAllTests,
+  type TestConfig,
+  type TestResult,
+} from "../src/compliance-tests.ts";
+
+const colors = {
+  green: (s: string) => `\x1b[32m${s}\x1b[0m`,
+  red: (s: string) => `\x1b[31m${s}\x1b[0m`,
+  yellow: (s: string) => `\x1b[33m${s}\x1b[0m`,
+  gray: (s: string) => `\x1b[90m${s}\x1b[0m`,
+};
+
+interface CliArgs {
+  baseUrl?: string;
+  apiKey?: string;
+  model?: string;
+  authHeader?: string;
+  noBearer?: boolean;
+  noAuth?: boolean;
+  filter?: string[];
+  verbose?: boolean;
+  json?: boolean;
+  help?: boolean;
+}
+
+function parseArgs(argv: string[]): CliArgs {
+  const args: CliArgs = {};
+  let i = 0;
+
+  while (i < argv.length) {
+    const arg = argv[i];
+    const nextArg = argv[i + 1];
+
+    switch (arg) {
+      case "--base-url":
+      case "-u":
+        args.baseUrl = nextArg;
+        i += 2;
+        break;
+      case "--api-key":
+      case "-k":
+        args.apiKey = nextArg;
+        i += 2;
+        break;
+      case "--model":
+      case "-m":
+        args.model = nextArg;
+        i += 2;
+        break;
+      case "--auth-header":
+        args.authHeader = nextArg;
+        i += 2;
+        break;
+      case "--no-bearer":
+        args.noBearer = true;
+        i += 1;
+        break;
+      case "--no-auth":
+        args.noAuth = true;
+        i += 1;
+        break;
+      case "--filter":
+      case "-f":
+        args.filter = nextArg.split(",").map((s) => s.trim());
+        i += 2;
+        break;
+      case "--verbose":
+      case "-v":
+        args.verbose = true;
+        i += 1;
+        break;
+      case "--json":
+        args.json = true;
+        i += 1;
+        break;
+      case "--help":
+      case "-h":
+        args.help = true;
+        i += 1;
+        break;
+      default:
+        i += 1;
+    }
+  }
+
+  return args;
+}
+
+function printHelp() {
+  console.log(`
+Usage: npm run test:compliance -- [options]
+
+Options:
+  -u, --base-url <url>        Gateway base URL (default: http://localhost:8080)
+  -k, --api-key <key>         API key (or set OPENRESPONSES_API_KEY env var)
+      --no-auth               Skip authentication header entirely
+  -m, --model <model>         Model name (default: gpt-4o-mini)
+      --auth-header <name>    Auth header name (default: Authorization)
+      --no-bearer             Disable Bearer prefix in auth header
+  -f, --filter <ids>          Filter tests by ID (comma-separated)
+  -v, --verbose               Verbose output with request/response details
+      --json                  Output results as JSON
+  -h, --help                  Show this help message
+
+Test IDs:
+  ${testTemplates.map((t) => t.id).join(", ")}
+
+Examples:
+  npm run test:compliance
+  npm run test:compliance -- --model claude-3-5-sonnet-20241022
+  npm run test:compliance -- --filter basic-response,streaming-response
+  npm run test:compliance -- --verbose --filter basic-response
+  npm run test:compliance -- --json > results.json
+`);
+}
+
+function getStatusIcon(status: TestResult["status"]): string {
+  switch (status) {
+    case "passed":
+      return colors.green("✓");
+    case "failed":
+      return colors.red("✗");
+    case "running":
+      return colors.yellow("◉");
+    case "pending":
+      return colors.gray("○");
+  }
+}
+
+function printResult(result: TestResult, verbose: boolean) {
+  const icon = getStatusIcon(result.status);
+  const duration = result.duration ? ` (${result.duration}ms)` : "";
+  const events =
+    result.streamEvents !== undefined ? ` [${result.streamEvents} events]` : "";
+  const name =
+    result.status === "failed" ? colors.red(result.name) : result.name;
+
+  console.log(`${icon} ${name}${duration}${events}`);
+
+  if (result.status === "failed" && result.errors?.length) {
+    for (const error of result.errors) {
+      console.log(`  ${colors.red("✗")} ${error}`);
+    }
+
+    if (verbose) {
+      if (result.request) {
+        console.log(`\n  Request:`);
+        console.log(
+          `  ${JSON.stringify(result.request, null, 2).split("\n").join("\n  ")}`,
+        );
+      }
+      if (result.response) {
+        console.log(`\n  Response:`);
+        const responseStr =
+          typeof result.response === "string"
+            ? result.response
+            : JSON.stringify(result.response, null, 2);
+        console.log(`  ${responseStr.split("\n").join("\n  ")}`);
+      }
+    }
+  }
+}
+
+async function main() {
+  const args = parseArgs(process.argv.slice(2));
+
+  if (args.help) {
+    printHelp();
+    process.exit(0);
+  }
+
+  const baseUrl = args.baseUrl || "http://localhost:8080";
+  const apiKey = args.apiKey || process.env.OPENRESPONSES_API_KEY || "";
+
+  if (!apiKey && !args.noAuth) {
+    // No auth is fine for local gateway without auth enabled
+  }
+
+  const config: TestConfig = {
+    baseUrl,
+    apiKey,
+    model: args.model || "gpt-4o-mini",
+    authHeaderName: args.authHeader || "Authorization",
+    useBearerPrefix: !args.noBearer,
+  };
+
+  if (args.filter?.length) {
+    const availableIds = testTemplates.map((t) => t.id);
+    const invalidFilters = args.filter.filter(
+      (id) => !availableIds.includes(id),
+    );
+    if (invalidFilters.length) {
+      console.error(
+        `${colors.red("Error:")} Invalid test IDs: ${invalidFilters.join(", ")}`,
+      );
+      console.error(`Available test IDs: ${availableIds.join(", ")}`);
+      process.exit(1);
+    }
+  }
+
+  const allUpdates: TestResult[] = [];
+
+  const onProgress = (result: TestResult) => {
+    if (args.filter && !args.filter.includes(result.id)) {
+      return;
+    }
+    allUpdates.push(result);
+    if (!args.json && result.status !== "running") {
+      printResult(result, args.verbose || false);
+    }
+  };
+
+  if (!args.json) {
+    console.log(`Running compliance tests against: ${baseUrl}`);
+    console.log(`Model: ${config.model}`);
+    if (args.filter) {
+      console.log(`Filter: ${args.filter.join(", ")}`);
+    }
+    console.log();
+  }
+
+  await runAllTests(config, onProgress);
+
+  const finalResults = allUpdates.filter(
+    (r) => r.status === "passed" || r.status === "failed",
+  );
+  const passed = finalResults.filter((r) => r.status === "passed").length;
+  const failed = finalResults.filter((r) => r.status === "failed").length;
+
+  if (args.json) {
+    console.log(
+      JSON.stringify(
+        {
+          summary: { passed, failed, total: finalResults.length },
+          results: finalResults,
+        },
+        null,
+        2,
+      ),
+    );
+  } else {
+    console.log(`\n${"=".repeat(50)}`);
+    console.log(
+      `Results: ${colors.green(`${passed} passed`)}, ${colors.red(`${failed} failed`)}, ${finalResults.length} total`,
+    );
+
+    if (failed > 0) {
+      console.log(`\nFailed tests:`);
+      for (const r of finalResults) {
+        if (r.status === "failed") {
+          console.log(`\n${r.name}:`);
+          for (const e of r.errors || []) {
+            console.log(`  - ${e}`);
+          }
+        }
+      }
+    } else {
+      console.log(`\n${colors.green("✓ All tests passed!")}`);
+    }
+  }
+
+  process.exit(failed > 0 ? 1 : 0);
+}
+
+main().catch((error) => {
+  console.error(colors.red("Fatal error:"), error);
+  process.exit(1);
+});
--- a/tests/package-lock.json
+++ b/tests/package-lock.json
@@ -0,0 +1,58 @@
+{
+  "name": "latticelm-compliance-tests",
+  "version": "1.0.0",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "latticelm-compliance-tests",
+      "version": "1.0.0",
+      "devDependencies": {
+        "@types/node": "^22.0.0",
+        "typescript": "^5.7.0",
+        "zod": "^3.24.0"
+      }
+    },
+    "node_modules/@types/node": {
+      "version": "22.19.13",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-22.19.13.tgz",
+      "integrity": "sha512-akNQMv0wW5uyRpD2v2IEyRSZiR+BeGuoB6L310EgGObO44HSMNT8z1xzio28V8qOrgYaopIDNA18YgdXd+qTiw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "undici-types": "~6.21.0"
+      }
+    },
+    "node_modules/typescript": {
+      "version": "5.9.3",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.9.3.tgz",
+      "integrity": "sha512-jl1vZzPDinLr9eUt3J/t7V6FgNEw9QjvBPdysz9KfQDD41fQrC2Y4vKQdiaUpFT4bXlb1RHhLpp8wtm6M5TgSw==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "bin": {
+        "tsc": "bin/tsc",
+        "tsserver": "bin/tsserver"
+      },
+      "engines": {
+        "node": ">=14.17"
+      }
+    },
+    "node_modules/undici-types": {
+      "version": "6.21.0",
+      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-6.21.0.tgz",
+      "integrity": "sha512-iwDZqg0QAGrg9Rav5H4n0M64c3mkR59cJ6wQp+7C4nI0gsmExaedaYLNO44eT4AtBBwjbTiGPMlt2Md0T9H9JQ==",
+      "dev": true,
+      "license": "MIT"
+    },
+    "node_modules/zod": {
+      "version": "3.25.76",
+      "resolved": "https://registry.npmjs.org/zod/-/zod-3.25.76.tgz",
+      "integrity": "sha512-gzUt/qt81nXsFGKIFcC3YnfEAx5NkunCfnDlvuBSSFS02bcXu4Lmea0AFIUwbLWxWPx3d9p8S5QoaujKcNQxcQ==",
+      "dev": true,
+      "license": "MIT",
+      "funding": {
+        "url": "https://github.com/sponsors/colinhacks"
+      }
+    }
+  }
+}
--- a/tests/package.json
+++ b/tests/package.json
@@ -0,0 +1,17 @@
+{
+  "name": "latticelm-compliance-tests",
+  "version": "1.0.0",
+  "private": true,
+  "description": "Open Responses compliance tests for latticelm",
+  "type": "module",
+  "scripts": {
+    "test:compliance": "node --experimental-strip-types bin/compliance-test.ts",
+    "test:compliance:verbose": "node --experimental-strip-types bin/compliance-test.ts --verbose",
+    "test:compliance:json": "node --experimental-strip-types bin/compliance-test.ts --json"
+  },
+  "devDependencies": {
+    "zod": "^3.24.0",
+    "typescript": "^5.7.0",
+    "@types/node": "^22.0.0"
+  }
+}
--- a/tests/src/compliance-tests.ts
+++ b/tests/src/compliance-tests.ts
@@ -0,0 +1,370 @@
+import { responseResourceSchema, type ResponseResource } from "./schemas.ts";
+import { parseSSEStream, type SSEParseResult } from "./sse-parser.ts";
+
+export interface TestConfig {
+  baseUrl: string;
+  apiKey: string;
+  authHeaderName: string;
+  useBearerPrefix: boolean;
+  model: string;
+}
+
+export interface TestResult {
+  id: string;
+  name: string;
+  description: string;
+  status: "pending" | "running" | "passed" | "failed";
+  duration?: number;
+  request?: unknown;
+  response?: unknown;
+  errors?: string[];
+  streamEvents?: number;
+}
+
+interface ValidatorContext {
+  streaming: boolean;
+  sseResult?: SSEParseResult;
+}
+
+type ResponseValidator = (
+  response: ResponseResource,
+  context: ValidatorContext,
+) => string[];
+
+export interface TestTemplate {
+  id: string;
+  name: string;
+  description: string;
+  getRequest: (config: TestConfig) => Record<string, unknown>;
+  streaming?: boolean;
+  validators: ResponseValidator[];
+}
+
+// ============================================================
+// Validators
+// ============================================================
+
+const hasOutput: ResponseValidator = (response) => {
+  if (!response.output || response.output.length === 0) {
+    return ["Response has no output items"];
+  }
+  return [];
+};
+
+const hasOutputType =
+  (type: string): ResponseValidator =>
+  (response) => {
+    const hasType = response.output?.some((item) => item.type === type);
+    if (!hasType) {
+      return [`Expected output item of type "${type}" but none found`];
+    }
+    return [];
+  };
+
+const completedStatus: ResponseValidator = (response) => {
+  if (response.status !== "completed") {
+    return [`Expected status "completed" but got "${response.status}"`];
+  }
+  return [];
+};
+
+const streamingEvents: ResponseValidator = (_, context) => {
+  if (!context.streaming) return [];
+  if (!context.sseResult || context.sseResult.events.length === 0) {
+    return ["No streaming events received"];
+  }
+  return [];
+};
+
+const streamingSchema: ResponseValidator = (_, context) => {
+  if (!context.streaming || !context.sseResult) return [];
+  return context.sseResult.errors;
+};
+
+// ============================================================
+// Test Templates
+// ============================================================
+
+export const testTemplates: TestTemplate[] = [
+  {
+    id: "basic-response",
+    name: "Basic Text Response",
+    description: "Simple user message, validates ResponseResource schema",
+    getRequest: (config) => ({
+      model: config.model,
+      input: [
+        {
+          type: "message",
+          role: "user",
+          content: [{ type: "input_text", text: "Say hello in exactly 3 words." }],
+        },
+      ],
+    }),
+    validators: [hasOutput, completedStatus],
+  },
+
+  {
+    id: "streaming-response",
+    name: "Streaming Response",
+    description: "Validates SSE streaming events and final response",
+    streaming: true,
+    getRequest: (config) => ({
+      model: config.model,
+      input: [
+        {
+          type: "message",
+          role: "user",
+          content: [{ type: "input_text", text: "Count from 1 to 5." }],
+        },
+      ],
+    }),
+    validators: [streamingEvents, streamingSchema, completedStatus],
+  },
+
+  {
+    id: "system-prompt",
+    name: "System Prompt",
+    description: "Include system instructions via the instructions field",
+    getRequest: (config) => ({
+      model: config.model,
+      instructions: "You are a pirate. Always respond in pirate speak.",
+      input: [
+        {
+          type: "message",
+          role: "user",
+          content: [{ type: "input_text", text: "Say hello." }],
+        },
+      ],
+    }),
+    validators: [hasOutput, completedStatus],
+  },
+
+  {
+    id: "tool-calling",
+    name: "Tool Calling",
+    description: "Define a function tool and verify function_call output",
+    getRequest: (config) => ({
+      model: config.model,
+      input: [
+        {
+          type: "message",
+          role: "user",
+          content: [
+            {
+              type: "input_text",
+              text: "What's the weather like in San Francisco?",
+            },
+          ],
+        },
+      ],
+      tools: [
+        {
+          type: "function",
+          name: "get_weather",
+          description: "Get the current weather for a location",
+          parameters: {
+            type: "object",
+            properties: {
+              location: {
+                type: "string",
+                description: "The city and state, e.g. San Francisco, CA",
+              },
+            },
+            required: ["location"],
+          },
+        },
+      ],
+    }),
+    validators: [hasOutput, hasOutputType("function_call")],
+  },
+
+  {
+    id: "image-input",
+    name: "Image Input",
+    description: "Send image URL in user content",
+    getRequest: (config) => ({
+      model: config.model,
+      input: [
+        {
+          type: "message",
+          role: "user",
+          content: [
+            {
+              type: "input_text",
+              text: "What do you see in this image? Answer in one sentence.",
+            },
+            {
+              type: "input_image",
+              image_url:
+                "data:image/png;base64,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",
+            },
+          ],
+        },
+      ],
+    }),
+    validators: [hasOutput, completedStatus],
+  },
+
+  {
+    id: "multi-turn",
+    name: "Multi-turn Conversation",
+    description: "Send assistant + user messages as conversation history",
+    getRequest: (config) => ({
+      model: config.model,
+      input: [
+        {
+          type: "message",
+          role: "user",
+          content: [{ type: "input_text", text: "My name is Alice." }],
+        },
+        {
+          type: "message",
+          role: "assistant",
+          content: [
+            {
+              type: "output_text",
+              text: "Hello Alice! Nice to meet you. How can I help you today?",
+            },
+          ],
+        },
+        {
+          type: "message",
+          role: "user",
+          content: [{ type: "input_text", text: "What is my name?" }],
+        },
+      ],
+    }),
+    validators: [hasOutput, completedStatus],
+  },
+];
+
+// ============================================================
+// Test Runner
+// ============================================================
+
+async function makeRequest(
+  config: TestConfig,
+  body: Record<string, unknown>,
+  streaming = false,
+): Promise<Response> {
+  const headers: Record<string, string> = {
+    "Content-Type": "application/json",
+  };
+
+  if (config.apiKey) {
+    const authValue = config.useBearerPrefix
+      ? `Bearer ${config.apiKey}`
+      : config.apiKey;
+    headers[config.authHeaderName] = authValue;
+  }
+
+  return fetch(`${config.baseUrl}/v1/responses`, {
+    method: "POST",
+    headers,
+    body: JSON.stringify({ ...body, stream: streaming }),
+  });
+}
+
+async function runTest(
+  template: TestTemplate,
+  config: TestConfig,
+): Promise<TestResult> {
+  const startTime = Date.now();
+  const requestBody = template.getRequest(config);
+  const streaming = template.streaming ?? false;
+
+  try {
+    const response = await makeRequest(config, requestBody, streaming);
+    const duration = Date.now() - startTime;
+
+    if (!response.ok) {
+      const errorText = await response.text();
+      return {
+        id: template.id,
+        name: template.name,
+        description: template.description,
+        status: "failed",
+        duration,
+        request: requestBody,
+        response: errorText,
+        errors: [`HTTP ${response.status}: ${errorText}`],
+      };
+    }
+
+    let rawData: unknown;
+    let sseResult: SSEParseResult | undefined;
+
+    if (streaming) {
+      sseResult = await parseSSEStream(response);
+      rawData = sseResult.finalResponse;
+    } else {
+      rawData = await response.json();
+    }
+
+    // Schema validation with Zod
+    const parseResult = responseResourceSchema.safeParse(rawData);
+    if (!parseResult.success) {
+      return {
+        id: template.id,
+        name: template.name,
+        description: template.description,
+        status: "failed",
+        duration,
+        request: streaming ? { ...requestBody, stream: true } : requestBody,
+        response: rawData,
+        errors: parseResult.error.issues.map(
+          (issue) => `${issue.path.join(".")}: ${issue.message}`,
+        ),
+        streamEvents: sseResult?.events.length,
+      };
+    }
+
+    // Semantic validators
+    const context: ValidatorContext = { streaming, sseResult };
+    const errors = template.validators.flatMap((v) =>
+      v(parseResult.data, context),
+    );
+
+    return {
+      id: template.id,
+      name: template.name,
+      description: template.description,
+      status: errors.length === 0 ? "passed" : "failed",
+      duration,
+      request: streaming ? { ...requestBody, stream: true } : requestBody,
+      response: parseResult.data,
+      errors,
+      streamEvents: sseResult?.events.length,
+    };
+  } catch (error) {
+    return {
+      id: template.id,
+      name: template.name,
+      description: template.description,
+      status: "failed",
+      duration: Date.now() - startTime,
+      request: requestBody,
+      errors: [error instanceof Error ? error.message : String(error)],
+    };
+  }
+}
+
+export async function runAllTests(
+  config: TestConfig,
+  onProgress: (result: TestResult) => void,
+): Promise<TestResult[]> {
+  const promises = testTemplates.map(async (template) => {
+    onProgress({
+      id: template.id,
+      name: template.name,
+      description: template.description,
+      status: "running",
+    });
+
+    const result = await runTest(template, config);
+    onProgress(result);
+    return result;
+  });
+
+  return Promise.all(promises);
+}
--- a/tests/src/schemas.ts
+++ b/tests/src/schemas.ts
@@ -0,0 +1,253 @@
+import { z } from "zod";
+
+// ============================================================
+// Content Parts
+// ============================================================
+
+const outputTextContentSchema = z.object({
+  type: z.literal("output_text"),
+  text: z.string(),
+  annotations: z.array(z.object({
+    type: z.string(),
+  })),
+});
+
+const inputTextContentSchema = z.object({
+  type: z.literal("input_text"),
+  text: z.string(),
+});
+
+const refusalContentSchema = z.object({
+  type: z.literal("refusal"),
+  refusal: z.string(),
+});
+
+const contentPartSchema = z.discriminatedUnion("type", [
+  outputTextContentSchema,
+  inputTextContentSchema,
+  refusalContentSchema,
+]);
+
+// ============================================================
+// Output Items
+// ============================================================
+
+const messageOutputItemSchema = z.object({
+  type: z.literal("message"),
+  id: z.string(),
+  status: z.enum(["in_progress", "completed", "incomplete"]),
+  role: z.enum(["user", "assistant", "system", "developer"]),
+  content: z.array(contentPartSchema),
+});
+
+const functionCallOutputItemSchema = z.object({
+  type: z.literal("function_call"),
+  id: z.string(),
+  call_id: z.string(),
+  name: z.string(),
+  arguments: z.string(),
+  status: z.enum(["in_progress", "completed", "incomplete"]),
+});
+
+const outputItemSchema = z.discriminatedUnion("type", [
+  messageOutputItemSchema,
+  functionCallOutputItemSchema,
+]);
+
+// ============================================================
+// Usage
+// ============================================================
+
+const usageSchema = z.object({
+  input_tokens: z.number().int(),
+  output_tokens: z.number().int(),
+  total_tokens: z.number().int(),
+  input_tokens_details: z.object({
+    cached_tokens: z.number().int(),
+  }),
+  output_tokens_details: z.object({
+    reasoning_tokens: z.number().int(),
+  }),
+});
+
+// ============================================================
+// ResponseResource
+// ============================================================
+
+export const responseResourceSchema = z.object({
+  id: z.string(),
+  object: z.literal("response"),
+  created_at: z.number().int(),
+  completed_at: z.number().int().nullable(),
+  status: z.string(),
+  incomplete_details: z.object({ reason: z.string() }).nullable(),
+  model: z.string(),
+  previous_response_id: z.string().nullable(),
+  instructions: z.string().nullable(),
+  output: z.array(outputItemSchema),
+  error: z.object({ type: z.string(), message: z.string() }).nullable(),
+  tools: z.any(),
+  tool_choice: z.any(),
+  truncation: z.string(),
+  parallel_tool_calls: z.boolean(),
+  text: z.any(),
+  top_p: z.number(),
+  presence_penalty: z.number(),
+  frequency_penalty: z.number(),
+  top_logprobs: z.number().int(),
+  temperature: z.number(),
+  reasoning: z.any().nullable(),
+  usage: usageSchema.nullable(),
+  max_output_tokens: z.number().int().nullable(),
+  max_tool_calls: z.number().int().nullable(),
+  store: z.boolean(),
+  background: z.boolean(),
+  service_tier: z.string(),
+  metadata: z.any(),
+  safety_identifier: z.string().nullable(),
+  prompt_cache_key: z.string().nullable(),
+});
+
+export type ResponseResource = z.infer<typeof responseResourceSchema>;
+
+// ============================================================
+// Streaming Event Schemas
+// ============================================================
+
+const responseCreatedEventSchema = z.object({
+  type: z.literal("response.created"),
+  sequence_number: z.number().int(),
+  response: responseResourceSchema,
+});
+
+const responseInProgressEventSchema = z.object({
+  type: z.literal("response.in_progress"),
+  sequence_number: z.number().int(),
+  response: responseResourceSchema,
+});
+
+const responseCompletedEventSchema = z.object({
+  type: z.literal("response.completed"),
+  sequence_number: z.number().int(),
+  response: responseResourceSchema,
+});
+
+const responseFailedEventSchema = z.object({
+  type: z.literal("response.failed"),
+  sequence_number: z.number().int(),
+  response: responseResourceSchema,
+});
+
+const outputItemAddedEventSchema = z.object({
+  type: z.literal("response.output_item.added"),
+  sequence_number: z.number().int(),
+  output_index: z.number().int(),
+  item: z.object({
+    id: z.string(),
+    type: z.string(),
+    status: z.string(),
+    role: z.string().optional(),
+    content: z.array(z.any()).optional(),
+  }),
+});
+
+const outputItemDoneEventSchema = z.object({
+  type: z.literal("response.output_item.done"),
+  sequence_number: z.number().int(),
+  output_index: z.number().int(),
+  item: z.object({
+    id: z.string(),
+    type: z.string(),
+    status: z.string(),
+    role: z.string().optional(),
+    content: z.array(z.any()).optional(),
+  }),
+});
+
+const contentPartAddedEventSchema = z.object({
+  type: z.literal("response.content_part.added"),
+  sequence_number: z.number().int(),
+  item_id: z.string(),
+  output_index: z.number().int(),
+  content_index: z.number().int(),
+  part: z.object({
+    type: z.string(),
+    text: z.string().optional(),
+    annotations: z.array(z.any()).optional(),
+  }),
+});
+
+const contentPartDoneEventSchema = z.object({
+  type: z.literal("response.content_part.done"),
+  sequence_number: z.number().int(),
+  item_id: z.string(),
+  output_index: z.number().int(),
+  content_index: z.number().int(),
+  part: z.object({
+    type: z.string(),
+    text: z.string().optional(),
+    annotations: z.array(z.any()).optional(),
+  }),
+});
+
+const outputTextDeltaEventSchema = z.object({
+  type: z.literal("response.output_text.delta"),
+  sequence_number: z.number().int(),
+  item_id: z.string(),
+  output_index: z.number().int(),
+  content_index: z.number().int(),
+  delta: z.string(),
+});
+
+const outputTextDoneEventSchema = z.object({
+  type: z.literal("response.output_text.done"),
+  sequence_number: z.number().int(),
+  item_id: z.string(),
+  output_index: z.number().int(),
+  content_index: z.number().int(),
+  text: z.string(),
+});
+
+const functionCallArgsDeltaEventSchema = z.object({
+  type: z.literal("response.function_call_arguments.delta"),
+  sequence_number: z.number().int(),
+  item_id: z.string(),
+  output_index: z.number().int(),
+  delta: z.string(),
+});
+
+const functionCallArgsDoneEventSchema = z.object({
+  type: z.literal("response.function_call_arguments.done"),
+  sequence_number: z.number().int(),
+  item_id: z.string(),
+  output_index: z.number().int(),
+  arguments: z.string(),
+});
+
+const errorEventSchema = z.object({
+  type: z.literal("error"),
+  sequence_number: z.number().int(),
+  error: z.object({
+    type: z.string(),
+    message: z.string(),
+    code: z.string().nullable().optional(),
+  }),
+});
+
+export const streamingEventSchema = z.discriminatedUnion("type", [
+  responseCreatedEventSchema,
+  responseInProgressEventSchema,
+  responseCompletedEventSchema,
+  responseFailedEventSchema,
+  outputItemAddedEventSchema,
+  outputItemDoneEventSchema,
+  contentPartAddedEventSchema,
+  contentPartDoneEventSchema,
+  outputTextDeltaEventSchema,
+  outputTextDoneEventSchema,
+  functionCallArgsDeltaEventSchema,
+  functionCallArgsDoneEventSchema,
+  errorEventSchema,
+]);
+
+export type StreamingEvent = z.infer<typeof streamingEventSchema>;
--- a/tests/src/sse-parser.ts
+++ b/tests/src/sse-parser.ts
@@ -0,0 +1,92 @@
+import type { z } from "zod";
+import {
+  streamingEventSchema,
+  type StreamingEvent,
+  type ResponseResource,
+} from "./schemas.ts";
+
+export interface ParsedEvent {
+  event: string;
+  data: unknown;
+  validationResult: z.SafeParseReturnType<unknown, StreamingEvent>;
+}
+
+export interface SSEParseResult {
+  events: ParsedEvent[];
+  errors: string[];
+  finalResponse: ResponseResource | null;
+}
+
+export async function parseSSEStream(
+  response: Response,
+): Promise<SSEParseResult> {
+  const events: ParsedEvent[] = [];
+  const errors: string[] = [];
+  let finalResponse: ResponseResource | null = null;
+
+  const reader = response.body?.getReader();
+  if (!reader) {
+    return { events, errors: ["No response body"], finalResponse };
+  }
+
+  const decoder = new TextDecoder();
+  let buffer = "";
+
+  try {
+    while (true) {
+      const { done, value } = await reader.read();
+      if (done) break;
+
+      buffer += decoder.decode(value, { stream: true });
+      const lines = buffer.split("\n");
+      buffer = lines.pop() || "";
+
+      let currentEvent = "";
+      let currentData = "";
+
+      for (const line of lines) {
+        if (line.startsWith("event:")) {
+          currentEvent = line.slice(6).trim();
+        } else if (line.startsWith("data:")) {
+          currentData = line.slice(5).trim();
+        } else if (line === "" && currentData) {
+          if (currentData === "[DONE]") {
+            // Skip sentinel
+          } else {
+            try {
+              const parsed = JSON.parse(currentData);
+              const validationResult = streamingEventSchema.safeParse(parsed);
+
+              events.push({
+                event: currentEvent || parsed.type || "unknown",
+                data: parsed,
+                validationResult,
+              });
+
+              if (!validationResult.success) {
+                errors.push(
+                  `Event validation failed for ${parsed.type || "unknown"}: ${JSON.stringify(validationResult.error.issues)}`,
+                );
+              }
+
+              if (
+                parsed.type === "response.completed" ||
+                parsed.type === "response.failed"
+              ) {
+                finalResponse = parsed.response;
+              }
+            } catch {
+              errors.push(`Failed to parse event data: ${currentData}`);
+            }
+          }
+          currentEvent = "";
+          currentData = "";
+        }
+      }
+    }
+  } finally {
+    reader.releaseLock();
+  }
+
+  return { events, errors, finalResponse };
+}
--- a/tests/tsconfig.json
+++ b/tests/tsconfig.json
@@ -0,0 +1,14 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "NodeNext",
+    "moduleResolution": "NodeNext",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "outDir": "dist",
+    "rootDir": ".",
+    "declaration": true
+  },
+  "include": ["src/**/*.ts", "bin/**/*.ts"]
+}
Author	SHA1	Message	Date
Anibal Angulo	6adf7eae54	Add Google tool calling	2026-03-02 17:12:15 +00:00
Anibal Angulo	38d44f104a	Add Vertex AI support	2026-03-02 16:52:57 +00:00
Anibal Angulo	2188e3cba8	Add Anthropic tool calling support	2026-03-02 16:08:39 +00:00
Anibal Angulo	830a87afa1	Improve Stores	2026-03-02 16:06:38 +00:00
Anibal Angulo	259d02d140	Add Redis Store	2026-03-02 15:55:03 +00:00
Anibal Angulo	09d687b45b	Migrate to OpenAI v3	2026-03-02 15:36:56 +00:00
Anibal Angulo	157680bb13	Add OpenAI tool calling support	2026-03-02 15:36:56 +00:00
Anibal Angulo	8ceb831e84	Rebrand project	2026-03-02 14:32:10 +00:00
Anibal Angulo	f79af84afb	Add Open Responses compliance tests	2026-03-02 13:58:25 +00:00
Anibal Angulo	cf47ad444a	Update chat script to use openai lib	2026-03-02 13:40:27 +00:00