GitHub - zendev-sh/goai: Go AI SDK, the Go way. One unified API across 21+ providers. Streaming, structured output, MCP support, stdlib only. Go AI SDK for AI applications inspired by Vercel AI SDK.

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GoAI

AI SDK, the Go way.

Go SDK for building AI applications. One SDK, 22+ providers, MCP support.

Streaming Cold Start Memory

1.1x faster streaming, 24x faster cold start, 3.1x less memory vs Vercel AI SDK (benchmarks)

Website · Docs · Architecture · Providers · Examples


Inspired by the Vercel AI SDK. The same clean abstractions, idiomatically adapted for Go with generics, interfaces, and functional options.

What's New

v0.6.0 - OpenTelemetry tracing + metrics, context propagation via RequestInfo.Ctx, Langfuse data race fix. Changelog →

v0.5.8 - RunPod provider, Bedrock embeddings, and docs accuracy improvements. Changelog →

v0.5.1 - MCP (Model Context Protocol) client plus MiniMax provider support. Docs →

Features

  • 7 core functions: GenerateText, StreamText, GenerateObject[T], StreamObject[T], Embed, EmbedMany, GenerateImage
  • 22+ providers: OpenAI, Anthropic, Google, Bedrock, Azure, Vertex, Mistral, xAI, Groq, Cohere, DeepSeek, MiniMax, Fireworks, Together, DeepInfra, OpenRouter, Perplexity, Cerebras, Ollama, vLLM, RunPod, + generic OpenAI-compatible
  • Auto tool loop: Define tools with Execute handlers, set MaxSteps for GenerateText and StreamText
  • Structured output: GenerateObject[T] auto-generates JSON Schema from Go types via reflection
  • Streaming: Real-time text and partial object streaming via channels
  • Dynamic auth: TokenSource interface for OAuth, rotating keys, cloud IAM, with CachedTokenSource for TTL-based caching
  • Prompt caching: Automatic cache control for supported providers (Anthropic, Bedrock, MiniMax)
  • Citations/sources: Grounding and inline citations from xAI, Perplexity, Google, OpenAI
  • Web search: Built-in web search tools for OpenAI, Anthropic, Google, Groq. Model decides when to search
  • Code execution: Server-side Python sandboxes via OpenAI, Anthropic, Google. No local setup
  • Computer use: Anthropic computer, bash, text editor tools for autonomous desktop interaction
  • 20 provider-defined tools: Web fetch, file search, image generation, X search, and more - full list
  • MCP client: Connect to any MCP server (stdio, HTTP, SSE), auto-convert tools for use with GoAI
  • Observability: Built-in Langfuse and OpenTelemetry (OTel) integrations for tracing generations, tools, and multi-step loops
  • 9 lifecycle hooks: Observability (OnRequest, OnResponse, OnToolCallStart, OnToolCall, OnStepFinish, OnFinish) and interceptor (OnBeforeToolExecute, OnAfterToolExecute, OnBeforeStep) hooks for permission gates, secret scanning, output transformation, and loop control
  • Retry/backoff: Automatic retry with exponential backoff on retryable HTTP errors (429/5xx)
  • Minimal dependencies: Core depends on golang.org/x/oauth2 + one indirect (cloud.google.com/go/compute/metadata). Optional observability/otel submodule uses separate go.mod with OTel SDK.

Performance vs Vercel AI SDK

Metric GoAI Vercel AI SDK Improvement
Streaming throughput 1.46ms 1.62ms 1.1x faster
Cold start 569us 13.9ms 24x faster
Memory (1 stream) 220KB 676KB 3.1x less
GenerateText 56us 79us 1.4x faster

Mock HTTP server, identical SSE fixtures, Apple M2. Full report

Install

go get github.com/zendev-sh/goai@latest

Requires Go 1.25+.

Quick Start

Most hosted providers auto-resolve API keys from environment variables. Local/custom providers may require explicit options:

package main

import (
	"context"
	"fmt"
	"log"

	"github.com/zendev-sh/goai"
	"github.com/zendev-sh/goai/provider/openai"
)

func main() {
	// Reads OPENAI_API_KEY from environment automatically.
	model := openai.Chat("gpt-4o")

	result, err := goai.GenerateText(context.Background(), model,
		goai.WithPrompt("What is the capital of France?"),
	)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(result.Text)
}

Streaming

ctx := context.Background()

stream, err := goai.StreamText(ctx, model,
	goai.WithSystem("You are a helpful assistant."),
	goai.WithPrompt("Write a haiku about Go."),
)
if err != nil {
	log.Fatal(err)
}

for text := range stream.TextStream() {
	fmt.Print(text)
}

result := stream.Result()
if err := stream.Err(); err != nil {
	log.Fatal(err)
}
fmt.Printf("\nTokens: %d in, %d out\n",
	result.TotalUsage.InputTokens, result.TotalUsage.OutputTokens)

Streaming with tools:

import "github.com/zendev-sh/goai/provider"

stream, err := goai.StreamText(ctx, model,
	goai.WithPrompt("What's the weather in Tokyo?"),
	goai.WithTools(weatherTool),
	goai.WithMaxSteps(5),
)
for chunk := range stream.Stream() {
	switch chunk.Type {
	case provider.ChunkText:
		fmt.Print(chunk.Text)
	case provider.ChunkStepFinish:
		fmt.Println("\n[step complete]")
	}
}

Structured Output

Auto-generates JSON Schema from Go types. Works with OpenAI, Anthropic, and Google.

type Recipe struct {
	Name        string   `json:"name" jsonschema:"description=Recipe name"`
	Ingredients []string `json:"ingredients"`
	Steps       []string `json:"steps"`
	Difficulty  string   `json:"difficulty" jsonschema:"enum=easy|medium|hard"`
}

result, err := goai.GenerateObject[Recipe](ctx, model,
	goai.WithPrompt("Give me a recipe for chocolate chip cookies"),
)
if err != nil {
	log.Fatal(err)
}
fmt.Printf("Recipe: %s (%s)\n", result.Object.Name, result.Object.Difficulty)

Streaming partial objects:

stream, err := goai.StreamObject[Recipe](ctx, model,
	goai.WithPrompt("Give me a recipe for pancakes"),
)
if err != nil {
	log.Fatal(err)
}
for partial := range stream.PartialObjectStream() {
	fmt.Printf("\r%s (%d ingredients so far)", partial.Name, len(partial.Ingredients))
}
final, err := stream.Result()

Tools

Define tools with JSON Schema and an Execute handler. Set MaxSteps to enable the auto tool loop.

import "encoding/json"

weatherTool := goai.Tool{
	Name:        "get_weather",
	Description: "Get the current weather for a city.",
	InputSchema: json.RawMessage(`{
		"type": "object",
		"properties": {"city": {"type": "string", "description": "City name"}},
		"required": ["city"]
	}`),
	Execute: func(ctx context.Context, input json.RawMessage) (string, error) {
		var args struct{ City string `json:"city"` }
		if err := json.Unmarshal(input, &args); err != nil {
			return "", err
		}
		return fmt.Sprintf("22°C and sunny in %s", args.City), nil
	},
}

result, err := goai.GenerateText(ctx, model,
	goai.WithPrompt("What's the weather in Tokyo?"),
	goai.WithTools(weatherTool),
	goai.WithMaxSteps(3),
)
if err != nil {
	log.Fatal(err)
}
fmt.Println(result.Text) // "It's 22°C and sunny in Tokyo."

MCP (Model Context Protocol)

Connect to any MCP server and use its tools with GoAI. Supports stdio, Streamable HTTP, and legacy SSE transports.

import "github.com/zendev-sh/goai/mcp"

// Connect to any MCP server
transport := mcp.NewStdioTransport("npx", []string{"-y", "@modelcontextprotocol/server-filesystem", "."})
client := mcp.NewClient("my-app", "1.0", mcp.WithTransport(transport))
_ = client.Connect(ctx)
defer client.Close()

// Use MCP tools with GoAI
tools, _ := client.ListTools(ctx, nil)
goaiTools := mcp.ConvertTools(client, tools.Tools)

result, _ := goai.GenerateText(ctx, model,
    goai.WithTools(goaiTools...),
    goai.WithPrompt("List files in the current directory"),
    goai.WithMaxSteps(5),
)

See examples/mcp-tools and the MCP documentation for more.

Citations / Sources

Providers that support grounding (Google, xAI, Perplexity) or inline citations (OpenAI) return sources:

result, err := goai.GenerateText(ctx, model,
	goai.WithPrompt("What were the major news events today?"),
)
if err != nil {
	log.Fatal(err)
}

if len(result.Sources) > 0 {
	for _, s := range result.Sources {
		fmt.Printf("[%s] %s - %s\n", s.Type, s.Title, s.URL)
	}
}

// Sources are also available per-step in multi-step tool loops.
for _, step := range result.Steps {
	for _, s := range step.Sources {
		fmt.Printf("  Step source: %s\n", s.URL)
	}
}

Computer Use

See Provider-Defined Tools > Computer Use and examples/computer-use for Anthropic computer, bash, and text editor tools. Works with both Anthropic direct API and Bedrock.

Embeddings

ctx := context.Background()
model := openai.Embedding("text-embedding-3-small")

// Single
result, err := goai.Embed(ctx, model, "Hello world")
if err != nil {
	log.Fatal(err)
}
fmt.Printf("Dimensions: %d\n", len(result.Embedding))

// Batch (auto-chunked, parallel)
many, err := goai.EmbedMany(ctx, model, []string{"foo", "bar", "baz"},
	goai.WithMaxParallelCalls(4),
)
if err != nil {
	log.Fatal(err)
}

Image Generation

ctx := context.Background()
model := openai.Image("gpt-image-1")

result, err := goai.GenerateImage(ctx, model,
	goai.WithImagePrompt("A sunset over mountains, oil painting style"),
	goai.WithImageSize("1024x1024"),
)
if err != nil {
	log.Fatal(err)
}
os.WriteFile("sunset.png", result.Images[0].Data, 0644)

Also supported: Google Imagen (google.Image("imagen-4.0-generate-001")) and Vertex AI (vertex.Image(...)).

Observability

Built-in Langfuse and OpenTelemetry integrations. Nine lifecycle hooks cover the full generation pipeline -- observability providers use them to trace LLM calls, tool executions, and multi-step agent loops:

import "github.com/zendev-sh/goai/observability/langfuse"

// Credentials from env: LANGFUSE_PUBLIC_KEY, LANGFUSE_SECRET_KEY, LANGFUSE_HOST
result, err := goai.GenerateText(ctx, model,
    goai.WithPrompt("Hello"),
    goai.WithTools(weatherTool),
    goai.WithMaxSteps(5),
    langfuse.WithTracing(langfuse.TraceName("my-agent")),
)

Interceptor hooks let you control tool execution without modifying core code:

// Permission gate: block dangerous tools
goai.WithOnBeforeToolExecute(func(info goai.BeforeToolExecuteInfo) goai.BeforeToolExecuteResult {
    if info.ToolName == "delete_file" {
        return goai.BeforeToolExecuteResult{Skip: true, Result: "Permission denied."}
    }
    return goai.BeforeToolExecuteResult{}
}),

// Detect max-steps exhaustion
goai.WithOnFinish(func(info goai.FinishInfo) {
    if info.StepsExhausted {
        log.Printf("Loop exhausted after %d steps", info.TotalSteps)
    }
}),

See examples/hooks, examples/langfuse, examples/otel, and the observability docs for details.

Providers

Many providers auto-resolve credentials from environment variables. Others (for example ollama, vllm, compat) use explicit options:

// Auto-resolved: reads OPENAI_API_KEY from env
model := openai.Chat("gpt-4o")

// Explicit key (overrides env)
model := openai.Chat("gpt-4o", openai.WithAPIKey("sk-..."))

// Cloud IAM auth (Vertex, Bedrock)
model := vertex.Chat("gemini-2.5-pro",
	vertex.WithProject("my-project"),
	vertex.WithLocation("us-central1"),
)

// AWS Bedrock (reads AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_REGION from env)
model := bedrock.Chat("anthropic.claude-sonnet-4-6-v1:0")

// Local (Ollama, vLLM)
model := ollama.Chat("llama3", ollama.WithBaseURL("http://localhost:11434/v1"))

result, err := goai.GenerateText(ctx, model, goai.WithPrompt("Hello"))

Provider Table

Provider Chat Embed Image Auth E2E Import
OpenAI gpt-4o, o3, codex-* text-embedding-3-* gpt-image-1 OPENAI_API_KEY, OPENAI_BASE_URL, TokenSource Full provider/openai
Anthropic claude-* - - ANTHROPIC_API_KEY, ANTHROPIC_BASE_URL, TokenSource Full provider/anthropic
Google gemini-* text-embedding-004 imagen-* GOOGLE_GENERATIVE_AI_API_KEY / GEMINI_API_KEY, TokenSource Full provider/google
Bedrock anthropic.*, meta.* titan-embed-*, cohere.embed-*, nova-2-*, marengo-* - AWS keys, AWS_BEARER_TOKEN_BEDROCK, AWS_BEDROCK_BASE_URL Full provider/bedrock
Vertex gemini-* text-embedding-004 imagen-* TokenSource, ADC, or GOOGLE_API_KEY / GEMINI_API_KEY / GOOGLE_GENERATIVE_AI_API_KEY fallback Unit provider/vertex
Azure gpt-4o, claude-* - via Azure AZURE_OPENAI_API_KEY, TokenSource Full provider/azure
OpenRouter various - - OPENROUTER_API_KEY, TokenSource Unit provider/openrouter
Mistral mistral-large, magistral-* - - MISTRAL_API_KEY, TokenSource Full provider/mistral
Groq mixtral-*, llama-* - - GROQ_API_KEY, TokenSource Full provider/groq
xAI grok-* - - XAI_API_KEY, TokenSource Unit provider/xai
Cohere command-r-* embed-* - COHERE_API_KEY, TokenSource Unit provider/cohere
DeepSeek deepseek-* - - DEEPSEEK_API_KEY, TokenSource Unit provider/deepseek
MiniMax MiniMax-M2.7, MiniMax-M2.5, MiniMax-M2.1, MiniMax-M2 - - MINIMAX_API_KEY, MINIMAX_BASE_URL, TokenSource Full provider/minimax
Fireworks various - - FIREWORKS_API_KEY, TokenSource Unit provider/fireworks
Together various - - TOGETHER_AI_API_KEY (or TOGETHER_API_KEY), TokenSource Unit provider/together
DeepInfra various - - DEEPINFRA_API_KEY, TokenSource Unit provider/deepinfra
Perplexity sonar-* - - PERPLEXITY_API_KEY, TokenSource Unit provider/perplexity
Cerebras llama-* - - CEREBRAS_API_KEY, TokenSource Unit provider/cerebras
Ollama local models local models - none Unit provider/ollama
vLLM local models local models - Optional auth via WithAPIKey / WithTokenSource Unit provider/vllm
RunPod any vLLM model - - RUNPOD_API_KEY, TokenSource Unit provider/runpod
Compat any OpenAI-compatible any - configurable Unit provider/compat

E2E column: "Full" = tested with real API calls. "Unit" = tested with mock HTTP servers (100% coverage).

Tested Models

E2E tested - 103 models across 7 providers (real API calls, click to expand)

Last run: 2026-03-27. 103 models tested (generate + stream).

Provider Models E2E tested (generate + stream)
Google (9) gemini-2.5-flash, gemini-2.5-flash-lite, gemini-2.5-pro (stream), gemini-3-flash-preview, gemini-3-pro-preview, gemini-3.1-pro-preview, gemini-2.0-flash, gemini-flash-latest, gemini-flash-lite-latest
Azure (21) claude-opus-4-6, claude-sonnet-4-6, DeepSeek-V3.2, gpt-4.1, gpt-4.1-mini, gpt-5, gpt-5-codex, gpt-5-mini, gpt-5-pro, gpt-5.1, gpt-5.1-codex, gpt-5.1-codex-max, gpt-5.1-codex-mini, gpt-5.2, gpt-5.2-codex, gpt-5.3-codex, gpt-5.4, gpt-5.4-pro, Kimi-K2.5, model-router, o3
Bedrock (61) Anthropic: claude-sonnet-4-6, claude-sonnet-4-5, claude-sonnet-4, claude-opus-4-6-v1, claude-opus-4-5, claude-opus-4-1, claude-haiku-4-5, claude-3-5-sonnet, claude-3-5-haiku, claude-3-haiku · Amazon: nova-micro, nova-lite, nova-pro, nova-premier, nova-2-lite · Meta: llama4-scout, llama4-maverick, llama3-3-70b, llama3-2-{90,11,3,1}b, llama3-1-{70,8}b, llama3-{70,8}b · Mistral: mistral-large, mixtral-8x7b, mistral-7b, ministral-3-{14,8}b, voxtral-{mini,small} · Others: deepseek.v3, deepseek.r1, ai21.jamba-1-5-{mini,large}, cohere.command-r{-plus,}, google.gemma-3-{4,12,27}b, minimax.{m2,m2.1}, moonshotai.kimi-k2{-thinking,.5}, nvidia.nemotron-nano-{12,9}b, openai.gpt-oss-{120,20}b{,-safeguard}, qwen.qwen3-{32,235,coder-30,coder-480}b, qwen.qwen3-next-80b, writer.palmyra-{x4,x5}, zai.glm-4.7{,-flash}
Groq (2) llama-3.1-8b-instant, llama-3.3-70b-versatile
Mistral (5) mistral-small-latest, mistral-large-latest, devstral-small-2507, codestral-latest, magistral-medium-latest
Cerebras (1) llama3.1-8b
MiniMax (4) MiniMax-M2.7, MiniMax-M2.5, MiniMax-M2.1, MiniMax-M2 (generate + stream + tools + thinking)
Unit tested (mock HTTP server, 100% coverage, click to expand)
Provider Models in unit tests
OpenAI gpt-4o, o3, text-embedding-3-small, dall-e-3, gpt-image-1
Anthropic claude-sonnet-4-20250514, claude-sonnet-4-5-20241022, claude-sonnet-4-6-20260310
Google gemini-2.5-flash, gemini-2.5-flash-image, imagen-4.0-fast-generate-001, text-embedding-004
Bedrock us.anthropic.claude-sonnet-4-6, anthropic.claude-sonnet-4-20250514-v1:0, meta.llama3-70b
Azure gpt-4o, gpt-5.2-chat, dall-e-3, claude-sonnet-4-6
Vertex gemini-2.5-pro, imagen-3.0-generate-002, text-embedding-004
Cohere command-r-plus, command-a-reasoning, embed-v4.0
Mistral mistral-large-latest
Groq llama-3.3-70b-versatile
xAI grok-3
DeepSeek deepseek-chat
DeepInfra meta-llama/Llama-3.3-70B-Instruct
Fireworks accounts/fireworks/models/llama-v3p3-70b-instruct
OpenRouter anthropic/claude-sonnet-4
Perplexity sonar-pro
Together meta-llama/Llama-3.3-70B-Instruct-Turbo
Cerebras llama-3.3-70b
Ollama llama3, llama3.2:1b, nomic-embed-text
vLLM meta-llama/Llama-3-8b
RunPod meta-llama/Llama-3.3-70B-Instruct

Custom / Self-Hosted

Use the compat provider for any OpenAI-compatible endpoint:

model := compat.Chat("my-model",
	compat.WithBaseURL("https://my-api.example.com/v1"),
	compat.WithAPIKey("..."),
)

Dynamic Auth with TokenSource

For OAuth, rotating keys, or cloud IAM:

ts := provider.CachedTokenSource(func(ctx context.Context) (*provider.Token, error) {
	tok, err := fetchOAuthToken(ctx)
	return &provider.Token{
		Value:     tok.AccessToken,
		ExpiresAt: tok.Expiry,
	}, err
})

model := openai.Chat("gpt-4o", openai.WithTokenSource(ts))

CachedTokenSource handles TTL-based caching (zero ExpiresAt = cache forever), thread-safe refresh without holding locks during network calls, and manual token invalidation via the InvalidatingTokenSource interface.

AWS Bedrock

Native Converse API with SigV4 signing (no AWS SDK dependency). Supports cross-region inference fallback, extended thinking, and image/document input:

model := bedrock.Chat("anthropic.claude-sonnet-4-6-v1:0",
	bedrock.WithRegion("us-west-2"),
	bedrock.WithReasoningConfig(bedrock.ReasoningConfig{
		Type:         bedrock.ReasoningEnabled,
		BudgetTokens: 4096,
	}),
)

Auto-resolves AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_REGION from environment. Cross-region fallback retries with us. prefix on model ID mismatch errors.

Azure OpenAI

Supports both OpenAI models (GPT, o-series) and Claude models (routed to Azure Anthropic endpoint automatically):

// OpenAI models
model := azure.Chat("gpt-4o",
	azure.WithEndpoint("https://my-resource.openai.azure.com"),
)

// Claude models (auto-routed to Anthropic endpoint)
model := azure.Chat("claude-sonnet-4-6",
	azure.WithEndpoint("https://my-resource.openai.azure.com"),
)

Auto-resolves AZURE_OPENAI_API_KEY, AZURE_OPENAI_ENDPOINT (or AZURE_RESOURCE_NAME) from environment.

Response Metadata

Every result includes provider response metadata:

result, _ := goai.GenerateText(ctx, model, goai.WithPrompt("Hello"))
fmt.Printf("Request ID: %s\n", result.Response.ID)
fmt.Printf("Model used: %s\n", result.Response.Model)

Options Reference

Generation Options

Option Description Default
WithSystem(s) System prompt -
WithPrompt(s) Single user message -
WithMessages(...) Conversation history -
WithTools(...) Available tools -
WithMaxOutputTokens(n) Response length limit provider default
WithTemperature(t) Randomness (0.0-2.0) provider default
WithTopP(p) Nucleus sampling provider default
WithTopK(k) Top-K sampling provider default
WithFrequencyPenalty(p) Frequency penalty provider default
WithPresencePenalty(p) Presence penalty provider default
WithSeed(s) Deterministic generation -
WithStopSequences(...) Stop triggers -
WithMaxSteps(n) Tool loop iterations 1 (no loop)
WithMaxRetries(n) Retries on 429/5xx 2
WithTimeout(d) Overall timeout none
WithHeaders(h) Per-request HTTP headers -
WithProviderOptions(m) Provider-specific params -
WithPromptCaching(b) Enable prompt caching false
WithToolChoice(tc) "auto", "none", "required", or tool name -

Lifecycle Hooks

Option Description
WithOnRequest(fn) Called before each API call
WithOnResponse(fn) Called after each API call
WithOnToolCallStart(fn) Called before each tool execution begins
WithOnToolCall(fn) Called after each tool execution
WithOnStepFinish(fn) Called after each tool loop step
WithOnFinish(fn) Called once after all steps complete (carries StepsExhausted)
WithOnBeforeToolExecute(fn) Intercept before tool Execute -- can skip, override ctx/input
WithOnAfterToolExecute(fn) Intercept after tool Execute -- can modify output/error
WithOnBeforeStep(fn) Intercept before step 2+ -- can inject messages or stop loop

Structured Output Options

Option Description
WithExplicitSchema(s) Override auto-generated JSON Schema
WithSchemaName(n) Schema name for provider (default "response")

Embedding Options

Option Description Default
WithMaxParallelCalls(n) Batch parallelism 4
WithEmbeddingProviderOptions(m) Embedding provider params -

Image Options

Option Description
WithImagePrompt(s) Text description
WithImageCount(n) Number of images
WithImageSize(s) Dimensions (e.g., "1024x1024")
WithAspectRatio(s) Aspect ratio (e.g., "16:9")
WithImageMaxRetries(n) Retries on 429/5xx
WithImageTimeout(d) Overall timeout
WithImageProviderOptions(m) Image provider params

Error Handling

GoAI generation and image APIs return typed errors for actionable failure modes (MCP client APIs return *mcp.MCPError):

result, err := goai.GenerateText(ctx, model, goai.WithPrompt("..."))
if err != nil {
	var overflow *goai.ContextOverflowError
	var apiErr *goai.APIError
	switch {
	case errors.As(err, &overflow):
		// Prompt too long - truncate and retry
	case errors.As(err, &apiErr):
		if apiErr.IsRetryable {
			// 429 rate limit, 503 - already retried MaxRetries times
		}
		fmt.Printf("API error %d: %s\n", apiErr.StatusCode, apiErr.Message)
		// HTTP API errors include ResponseBody and ResponseHeaders for debugging
	default:
		// Network error, context cancelled, etc.
	}
}

Error types:

Type Fields When
APIError StatusCode, Message, IsRetryable, ResponseBody, ResponseHeaders Non-2xx API responses
ContextOverflowError Message, ResponseBody Prompt exceeds model context window

Retry behavior: automatic exponential backoff on retryable HTTP errors (429/5xx, plus OpenAI 404 propagation). retry-after-ms and numeric Retry-After (seconds) are respected. Retries apply to request-level failures (including initial stream connection), not mid-stream error events.

Provider-Defined Tools

Providers expose built-in tools that the model can invoke server-side. GoAI supports 20 provider-defined tools across 5 providers:

Provider Tools Import
Anthropic Computer, Computer_20251124, Bash, TextEditor, TextEditor_20250728, WebSearch, WebSearch_20260209, WebFetch, CodeExecution, CodeExecution_20250825 provider/anthropic
OpenAI WebSearch, CodeInterpreter, FileSearch, ImageGeneration provider/openai
Google GoogleSearch, URLContext, CodeExecution provider/google
xAI WebSearch, XSearch provider/xai
Groq BrowserSearch provider/groq

All tools follow the same pattern: create a definition with <provider>.Tools.ToolName() (e.g., openai.Tools, anthropic.Tools), then pass it as a goai.Tool:

// Example: def := openai.Tools.WebSearch(openai.WithSearchContextSize("medium"))
def := <provider>.Tools.ToolName(options...)
result, _ := goai.GenerateText(ctx, model,
    goai.WithTools(goai.Tool{
        Name:                   def.Name,
        ProviderDefinedType:    def.ProviderDefinedType,
        ProviderDefinedOptions: def.ProviderDefinedOptions,
    }),
)

Web Search

The model searches the web and returns grounded responses. Available from OpenAI, Anthropic, Google, and Groq.

// OpenAI (via Responses API) - also works via Azure
def := openai.Tools.WebSearch(openai.WithSearchContextSize("medium"))

// Anthropic (via Messages API) - also works via Bedrock
def := anthropic.Tools.WebSearch(anthropic.WithMaxUses(5))

// Google (grounding with Google Search) - returns Sources
def := google.Tools.GoogleSearch()
// result.Sources contains grounding URLs from Google Search

// Groq (interactive browser search)
def := groq.Tools.BrowserSearch()

Code Execution

The model writes and runs code in a sandboxed environment. Server-side, no local setup needed.

// OpenAI Code Interpreter - Python sandbox via Responses API
def := openai.Tools.CodeInterpreter()

// Anthropic Code Execution - Python sandbox via Messages API
def := anthropic.Tools.CodeExecution() // v20260120, GA, no beta needed

// Google Code Execution - Python sandbox via Gemini API
def := google.Tools.CodeExecution()

Web Fetch

Claude fetches and processes content from specific URLs directly.

def := anthropic.Tools.WebFetch(
    anthropic.WithWebFetchMaxUses(3),
    anthropic.WithCitations(true),
)

File Search

Semantic search over uploaded files in vector stores (OpenAI Responses API).

def := openai.Tools.FileSearch(
    openai.WithVectorStoreIDs("vs_abc123"),
    openai.WithMaxNumResults(5),
)

Image Generation

LLM generates images inline during conversation (different from goai.GenerateImage() which calls the Images API directly).

def := openai.Tools.ImageGeneration(
    openai.WithImageQuality("low"),
    openai.WithImageSize("1024x1024"),
)
// On Azure, also set: azure.WithHeaders(map[string]string{
//     "x-ms-oai-image-generation-deployment": "gpt-image-1.5",
// })

Computer Use

Anthropic computer, bash, and text editor tools for autonomous desktop interaction. Client-side execution required.

computerDef := anthropic.Tools.Computer(anthropic.ComputerToolOptions{
    DisplayWidthPx: 1920, DisplayHeightPx: 1080,
})
bashDef := anthropic.Tools.Bash()
textEditorDef := anthropic.Tools.TextEditor()
// Wrap each with an Execute handler for client-side execution

URL Context

Gemini fetches and processes web content from URLs in the prompt.

def := google.Tools.URLContext()

See examples/ for complete runnable examples of each tool.

Examples

See the examples/ directory:

Project Structure

goai/                       # Core SDK
├── provider/               # Provider interface + shared types
│   ├── provider.go         # LanguageModel, EmbeddingModel, ImageModel interfaces
│   ├── types.go            # Message, Part, Usage, StreamChunk, etc.
│   ├── token.go            # TokenSource, CachedTokenSource
│   ├── openai/             # OpenAI (Chat Completions + Responses API)
│   ├── anthropic/          # Anthropic (Messages API)
│   ├── google/             # Google Gemini (REST API)
│   ├── bedrock/            # AWS Bedrock (Converse API + SigV4 + EventStream)
│   ├── vertex/             # Google Vertex AI (OpenAI-compat)
│   ├── azure/              # Azure OpenAI
│   ├── cohere/             # Cohere (Chat v2 + Embed)
│   ├── minimax/            # MiniMax (Anthropic-compatible API)
│   ├── compat/             # Generic OpenAI-compatible
│   	└── ...                 # 13 more OpenAI-compatible providers
├── internal/
│   ├── openaicompat/       # Shared codec for 13 OpenAI-compat providers
│   ├── gemini/             # Schema sanitization (Vertex, Google)
│   ├── sse/                # SSE line parser
│   └── httpc/              # HTTP utilities
├── examples/               # Usage examples
└── bench/                  # Performance benchmarks (GoAI vs Vercel AI SDK)
    ├── fixtures/           # Shared SSE test fixtures
    ├── go/                 # Go benchmarks (go test -bench)
    ├── ts/                 # TypeScript benchmarks (Bun + Tinybench)
    ├── collect.sh          # Result aggregation → report
    └── Makefile            # make bench-all

Contributing

See CONTRIBUTING.md.

License

MIT