Concat is pitched as a free CapCut replacement, and its listed features include auto-captions, text-to-speech, background removal, keyframes, multi-track cutting, 4K export. For developers, the more important line is further down. Concat ships an MCP server built in, so an AI agent can edit video with it, plus a JSON-RPC API for scripts. A video editor that an agent can drive, running entirely on your own disk, is a different tool from a consumer app with an AI button.

The README describes Concat as an open-source editor for macOS, Windows, Linux and Android, with iPhone and iPad builds that are sideloaded. Everything runs on a native Rust engine with a GPU compositor. It is licensed AGPL-3.0 and, in its own words, in beta: it works, and it still has edges.

Local by design

The README's "none of the catches" list is short: no watermark, no account, no subscription, no upload. The AI pieces follow the same rule. Captions use local Whisper, where you pick a model size and get styled captions on the timeline.…