Mistle

Mistle is an open source platform for running background engineering agents that work across repositories, review pull requests, investigate bugs and prepare code changes, then hand the results back for human review. It is aimed at engineering teams that want agent work to run alongside their existing tools rather than in a single editor session. Users configure agent sandboxes by choosing the agent harness, the repositories and the tools each session starts with, and a setup script builds snapshots that can be refreshed on a cron schedule so sessions start quickly. Agents can be triggered by events such as GitHub pull requests being opened, Slack app mentions, webhooks or scheduled jobs. GitHub and Slack accounts can be linked so that agent work is attributed to the person who started it, and any agent session can be opened to inspect, steer or review what the agent did. Listed integrations include GitHub, Slack, Linear and OpenAI Codex, with more described as growing. Example workflows include turning issues into pull requests, investigating production bugs, reviewing pull requests and running scheduled maintenance such as handling dependency update pull requests. Mistle can be run locally with a Docker Compose installer published in its GitHub repository, which starts a local dashboard. The site publishes no pricing, and the software is described as open source.