Control Concat from a script · Guides

Anything the window can do to a project, a program can do through the API. Here is where that starts.

Concat has a JSON-RPC, gRPC and MCP API, plus a CLI, so scripts and AI agents can cut video with it too. The developer docs are the reference. This page is the short version for people who have never opened them.

Three ways in

Transport	How you reach it
JSON-RPC 2.0 lines	`concat-cli api` on stdin, `concat-cli serve` on a TCP or Unix socket, or the window’s Settings › Remote page while the editor is open
gRPC over HTTP/2	`concat-cli serve --grpc`, in a build with the `grpc` feature
MCP	An MCP server exposing the API as tools. See MCP for what exists today

All three carry the same methods, payloads and errors.

Five things to know

Call version first. Its capabilities list says what this build serves.
Projects are folders. Every method names a project by its folder path, and the folder must be open first.
Edits are commands. edit.apply carries the window’s own edit vocabulary, unchanged.
Exports are jobs. export.run returns at once; progress comes as events; one export runs at a time.
Errors have codes. Branch on code; show message to a person.

Ready for more? Start with the quick start, then the API overview.