Agent Host Protocol

A synchronized, multi-client state protocol for AI agent sessions.

Read the documentation →

The Agent Host Protocol (AHP) defines how a portable, standalone sessions server communicates with its clients. Multiple clients can connect to the server and see a synchronized view of AI agent sessions through immutable state, pure reducers, and write-ahead reconciliation.

Language	Package	Version	Source
Rust	ahp · ahp-types · ahp-ws		clients/rust/ · CHANGELOG
TypeScript	@microsoft/agent-host-protocol		clients/typescript/ · CHANGELOG
Kotlin	com.microsoft.agenthostprotocol:agent-host-protocol		clients/kotlin/ · CHANGELOG
Go	github.com/microsoft/agent-host-protocol/clients/go		clients/go/ · CHANGELOG
Swift	SwiftPM: microsoft/agent-host-protocol		package README · CHANGELOG
.NET	Microsoft.VisualStudioCode.AgentHostProtocol · Microsoft.VisualStudioCode.AgentHostProtocol.Abstractions		clients/dotnet/ · CHANGELOG

Other clients: AHPX (CLI + Node.js client) and VS Code (built-in Agent Sessions client).

The Rust, Swift, Go, and .NET SDKs ship a MultiHostClient for talking to two or more hosts at once (single-host consumers use the same API via MultiHostClient::single / .single(...) / hosts.Single(...) / MultiHostClient.SingleAsync(...)). See Connecting to Multiple Hosts.

• VS Code agent host — The reference AHP server implementation (src/vs/platform/agentHost/node/).
• pi-ahp — An open-source AHP host for the pi coding agent, exposing pi sessions to AHP clients over WebSocket.

Each language client and the spec itself release independently on their own SemVer tracks. See docs/specification/versioning.md for the protocol-level rules and RELEASING.md for the release mechanics (tag conventions, CHANGELOG / metadata enforcement, required CI environments).

# Install dependencies
npm install

# Start local dev server
npm run docs:dev

# Build for production
npm run docs:build

# Preview production build
npm run docs:preview

MIT