Open source background agents

Run engineering agents that work across repositories, review pull requests, investigate bugs, and prepare code changes for human review.

View GitHub

Mistle session workspace showing an agent plan, pull request summary, and code diff

Run locally

Install Mistle with Docker

The GitHub README ships a local Docker Compose installer. It creates the local config under ~/.mistle/local, preserves an existing env file, and starts the local stack.

Quick start

1. Install and start Mistle

curl -fsSL https://raw.githubusercontent.com/mistlehq/mistle/main/deploy/compose/local/install.sh | sh

2. Open the dashboard at localhost:3000 .

3. For email OTP auth, retrieve the OTP from Mailpit at localhost:8025 .

Stop the local stack

~/.mistle/local/down.sh

Read the GitHub install notes

Features

Everything engineering agents need

Connect the tools your team already uses

Start with GitHub, Slack, OpenAI, and a growing set of integrations.

Configure agent sandboxes

Choose the agent harness, repositories and tools each session starts with. Configure the setup script that is used to create and refresh snapshots.

Integration

Resources & tools

OpenAI Codex

GitHub 2 repos, github-cli

Linear linear-mcp

Attribute agent work to the right person

Link GitHub and Slack accounts so work maps back to the human who started it.

Linked accounts

GitHub jlowhy

Slack jonathan

Scheduled snapshots

Start sessions quickly from snapshots, with scheduled refreshes to keep tools and dependencies up to date.

Automatic refresh

Cron expression

0 9 * * 1

Jump into any agent session

Open a linked session to inspect, steer, or review agent work.

Mistlebot says

I'll audit the Dependabot PRs and run the relevant checks. (View session)

Trigger work from events or schedules

Respond to webhooks, app mentions, or cron schedules to automate engineering workflows.

Events

github.pull_request.opened

slack.app_mention

Schedules

0 9 * * 1-5

daily at 9:00

Use cases

Automate workflows from the tools you use

Turn issues into verified PRs

@mistle build the invite flow from this ticket

GitHub

Linear

OpenAI

Investigate production bugs

@mistle investigate checkout timeout

Slack

SigNoz

AWS

Review PRs automatically

@mistle review diff, run tests, and harden coverage

GitHub

Run scheduled maintenance

@mistle review and merge dependabot PRs

GitHub

More workflows

Build agents beyond engineering

Maya 9:08 AM

@Mistle-Eng please investigate DSN-7wnj3. Tensorlake cannot start the designer session.

Mistle-Eng APP 9:09 AM

I'm checking the session record, provider logs, and sandbox build evidence. I'll avoid changing runtime state while diagnosing.

Mistle-Eng APP 9:12 AM

Confirmed the configured designer image was not publicly pullable. I opened PR #3206 to publish the sandbox-designer-base image.

Nadia 9:12 AM

@Mistle-Product why did Acme trial activation drop in the workspace setup funnel?

Mistle-Product APP 9:13 AM

PostHog shows the drop starts after invite import. I opened a Linear issue with the Acme segment and linked the latest feedback.

Leah 9:16 AM

@Mistle-Marketing which Q3 launch campaigns need attention before the weekly review?

Mistle-Marketing APP 9:17 AM

Google Ads spend is up for the Agent Builder campaign while trial starts are flat. I drafted notes and flagged two ad groups for review.

Ryan 9:20 AM

@Mistle-Sales can you prep the account brief for today's Acme call?

Mistle-Sales APP 9:21 AM

I pulled HubSpot activity, demo notes, and recent emails. The brief is ready with open objections and suggested follow-up questions.

Avery 9:24 AM

@Mistle-Admin what follow-ups are still open from last week's RevOps and product reviews?

Mistle-Admin APP 9:25 AM

I reviewed Calendar, Gmail, and Docs. There are five open follow-ups, and I prepared the action list by owner.

Iris 9:28 AM

@Mistle-HR where should I route the final feedback for Jordan Lee's staff engineer loop?

Mistle-HR APP 9:29 AM

I matched the notes to the staff engineer rubric and hiring process. I assigned debrief follow-ups to the loop owners.

Alex 9:32 AM

@Mistle-Finance why did Northstar Health's May invoice total change?

Mistle-Finance APP 9:33 AM

Stripe shows a seat-count increase and prorated credit. I reconciled it against the Northstar account and marked it for review.

Sam 9:36 AM

@Mistle-Legal does the CloudAtlas data processing addendum need legal review?

Mistle-Legal APP 9:37 AM

I compared it against the vendor playbook and prior MSAs. The indemnity language is nonstandard, so I assigned legal review.

Priya 9:40 AM

@Mistle-Support can you draft a reply for Thread #842 from Rook Labs?

Mistle-Support APP 9:41 AM

I checked the Gmail thread, help docs, and past tickets. I drafted the reply and noted when to escalate if Rook reports a bug.