thinwrap/llm (Go)

Unified, SDK-free, zero-dependency Go wrapper for chat completions (with streaming) and embeddings across 18 LLM providers. Switch vendor by changing the provider id + model; the input and output shapes stay identical. Stateless — bring your own *http.Client, no vendor SDKs.

import "github.com/thinwrap/llm-go"

Requires Go ≥ 1.18. No third-party dependencies — Bedrock's SigV4 is hand-rolled on crypto/*, SSE streaming on bufio.

Two-minute chat

chat, err := llm.NewChat(llm.OpenAI, llm.OpenAICompatConfig{APIKey: os.Getenv("OPENAI_API_KEY")})
if err != nil { log.Fatal(err) }

res, err := chat.Complete(ctx, llm.ChatInput{
    Model:    "gpt-4o-mini",
    Messages: []llm.ChatMessage{{Role: "user", Content: "Say hi in one word."}},
})
if err != nil {
    var ce *llm.ConnectorError
    if errors.As(err, &ce) { log.Printf("%s: %s", ce.ProviderCode, ce.ProviderMessage) }
    return
}
fmt.Println(res.Message.Content, res.Usage.TotalTokens)

Streaming

stream, err := chat.Stream(ctx, in)
if err != nil { return }
defer stream.Close()
for {
    delta, err := stream.Recv()
    if err == io.EOF { break }
    if err != nil { return }
    fmt.Print(delta.ContentDelta)
}

Providers

The provider id selects the connector; ChatInput / ChatResult are identical across all of them.

Chat (18): the 15 first-class OpenAI-compatible providers — OpenAI, AzureOpenAI, OpenRouter, Groq, Together, Fireworks, DeepSeek, XAI, Mistral, Perplexity, DeepInfra, Cloudflare, VLLM, Ollama, LMStudio — all take OpenAICompatConfig; plus 3 natives: Anthropic (AnthropicConfig), Bedrock (BedrockConfig), Gemini (GeminiConfig).

Embeddings (11): OpenAI, AzureOpenAI, OpenRouter, Together, Fireworks, Mistral, DeepInfra, Cloudflare, VLLM, Ollama, LMStudio (the OpenAI-float subset).

emb, _ := llm.NewEmbeddings(llm.OpenAI, llm.OpenAICompatConfig{APIKey: key})
out, _ := emb.Create(ctx, llm.EmbeddingsInput{Model: "text-embedding-3-small", Input: []string{"hello", "world"}})
// out.Embeddings is [][]float64 in input order

Per-provider details (endpoint, auth, quirks, passthrough keys) live in docs/providers/ — one page per provider.

Switching providers

// Same Complete(ctx, in) call, same ChatResult — id + model change only.
chat, _ := llm.NewChat(llm.Anthropic, llm.AnthropicConfig{APIKey: key})
// then in.Model = "claude-sonnet-4-5", etc.

OpenAICompatConfig covers all 15 first-class providers (APIKey, BaseURL, Headers); BaseURL is required for AzureOpenAI / Cloudflare and any self-host provider on a non-default host.

The ≥90% baseline & passthrough

Only fields ≥90% of providers support normalizably are first-class on ChatInput / ChatResult. Everything else rides through Passthrough (request) / Raw (response) and is never emulated:

res, _ := chat.Complete(ctx, llm.ChatInput{
    Model:    "...",
    Messages: msgs,
    Passthrough: &llm.Passthrough{Body: map[string]any{"logprobs": true}},
})
_ = res.Raw // verbatim vendor body — reasoning CoT, cached-token counts, cost, ...

Errors

Every failure is a *ConnectorError (errors.As): ProviderCode is one of rate_limited, auth_failed, provider_unavailable, invalid_request, context_length_exceeded, content_filtered, unknown. The raw Retry-After rides in Cause["retryAfter"] (+ parsed Cause["retryAfterSeconds"]) — there is no top-level retry field.

Relationship to the siblings

One of four thinwrap llm libraries sharing a normalized surface and byte-identical provider ids / error codes: TypeScript (@thinwrap/llm), PHP (thinwrap/llm), Go (this package), Python (thinwrap-llm).

Security

Report vulnerabilities privately — please do not open a public issue. Preferred: a private security advisory on this repository. Alternatively, email security@thinwrap.dev. Include the affected versions and a minimal reproduction if you have one.

A vulnerability in a provider's own API or service belongs to that vendor rather than to this wrapper — please report those upstream.

License

MIT © Dmitry Polyanovsky & contributors