The Anthropic SDK for Go is the official open-source client library for Anthropic’s Claude language models, maintained by Anthropic on GitHub. It gives Go developers typed, idiomatic access to the Claude API, including messages, streaming responses and tool use. The repository has gathered around 1,200 stars and is updated very actively, with the latest changes landing in October 2026.
Rather than hand-crafting HTTP requests to the Claude API, Go teams can use this SDK to build chat applications, agents and automation backed by Claude models. The library mirrors the structure of the REST API while adding Go-native ergonomics: strongly typed request and response structs, context support, configurable retries and timeouts, and helpers for server-sent event streaming. It covers the core Messages API as well as newer capabilities such as tool calling, extended thinking and batch processing as they are released. Because it is the vendor-maintained SDK, new model releases and API features typically arrive here first, and the generated code is paired with hand-written convenience layers for common patterns.
The repository follows Anthropic’s standard SDK layout shared across languages, with examples in the repo showing common patterns such as multi-turn conversations, streaming chat and tool-calling loops, which lowers the learning curve for teams already using the Anthropic SDKs in Python or TypeScript.
The SDK itself is free and open source under the MIT license. You only pay Anthropic for API usage itself, billed per token under your own Anthropic account; the library adds no extra cost.
Go developers and backend teams who want a supported, type-safe way to integrate Claude into services, command-line tools, agents and internal platforms without maintaining their own API client.