The Agentic Coding Protocol (ACP) is a protocol that standardizes communication between code editors (interactive programs for viewing and editing source code) and coding agents (programs that use generative AI to autonomously modify code).
The protocol is still under heavy development, and we aim to standardize it as we get confidence in the design by implementing it in various settings.
The protocol is newline-delimited JSON sent over stdin/stdout. When a code editor wants to start a session with an agent, it boots it as a sub-process (inheriting any environment variables) and sends an initialize request to get the state of the world.
If authentication is required, it can send authenticate to allow the agent to perform any authentication actions (like an Oauth flow).
Once the agent is ready, the client can send sendUserMessage requests with content from the user. The agent sends streamAssistantMessageChunk and related tool call messages to update the UI while handling the user's message, and finally responds when there will be no more output.
The schema is defined in schema.rs, and a type-script definition is generated to schema.ts.
This repo also contains interoperable implementations of the protocol for both Typescript and Rust.
