Anthropic SDK for Go

What it does

• Idiomatic Go with net/http-style streaming — zero-allocation event parsing
• Context-aware cancellation through context.Context — natural fit for Go servers
• Full Messages, Batch, Files, Token Counting, Vision coverage
• Tool use with strict schema validation via jsonschema tags
• Used by Cloudflare Workers, Anthropic's own internal services, and many Go-first agent stacks

When to use it

Best for high-throughput Go backends (Cloudflare Workers, k8s controllers), CLI tools written in Go, and any production agent where net/http streaming + context cancellation are first-class requirements. Pairs well with cobra for CLIs and chi/gin for HTTP frontends.

Getting started

go get github.com/anthropics/anthropic-sdk-go

Set ANTHROPIC_API_KEY (and ANTHROPIC_BASE_URL for Bedrock/Vertex) via os.Setenv or a config loader.

Things to know

The Go SDK tracks the Python SDK closely — most features ship within weeks of parity. Pin major versions; the streaming API surface has stabilised since v1.0 but earlier 0.x versions had breaking changes.