History

Michael Bolin 153338c20f docs: add barebones README for codex-app-server crate (#4671 )		2025-10-03 09:26:44 -07:00
..
src	feat: add file name to fuzzy search response (#4619 )	2025-10-02 18:19:13 -07:00
tests	chore: sandbox refactor 2 (#4653 )	2025-10-03 11:17:39 +01:00
Cargo.toml	fix: remove mcp-types from app server protocol (#4537 )	2025-10-01 02:16:26 +00:00
README.md	docs: add barebones README for codex-app-server crate (#4671 )	2025-10-03 09:26:44 -07:00

README.md

codex-app-server

codex app-server is the harness Codex uses to power rich interfaces such as the Codex VS Code extension. The message schema is currently unstable, but those who wish to build experimental UIs on top of Codex may find it valuable.

Protocol

Similar to MCP, codex app-server supports bidirectional communication, streaming JSONL over stdio. The protocol is JSON-RPC 2.0, though the "jsonrpc":"2.0" header is omitted.

Message Schema

Currently, you can dump a TypeScript version of the schema using codex generate-ts. It is specific to the version of Codex you used to run generate-ts, so the two are guaranteed to be compatible.

codex generate-ts --out DIR