Runner MCP README
The full upstream README, mirrored here for reference. Install config, tool schemas, adoption signals, and an original overview live on the Runner MCP listing page.
Runner MCP
Let an AI run tests and controlled staging operations on your own server without giving it a general-purpose remote shell.
Runner MCP is a security-first, self-hosted Model Context Protocol service. You configure the projects and operations that exist; the AI selects from those bounded capabilities instead of supplying arbitrary shell commands, executables, filesystem paths or service names.
An AIfordable project — secure software. Built with AI. Fairly priced.
Runner MCP is currently alpha. The canonical public distribution is available on PyPI, the official MCP Registry and GitHub Releases. The first fully aligned cross-registry release is v0.1.2.
Start here: 5-minute demo · Quickstart · Security model · Threat model
The difference in one table
| Approach | AI can inspect/run configured work | Arbitrary shell is the normal interface | Explicit audit/safety boundary |
|---|---|---|---|
| SSH / broad remote-control tool | Yes | Yes | Depends on the surrounding setup |
| Runner MCP | Yes | No | Yes — allow-lists, bounded output, emergency stop and approval gates |
Runner MCP is intentionally not a sandbox for untrusted code and does not claim to replace every operator maintenance tool. Its goal is narrower: routine AI-assisted development and staging operations should not require handing the AI an unrestricted shell.
Why Runner MCP exists
AI-assisted development becomes much more useful when the assistant can verify changes against real projects. But routine tasks such as reading a safe file, running a known test suite or checking a staging service do not require the authority of a general-purpose remote shell.
Runner MCP turns those routine operations into explicit capabilities. The operator configures projects and named actions locally; the AI client selects from those capabilities instead of supplying arbitrary commands, executable paths or private infrastructure values.
The original motivation was practical: reduce the day-to-day dependency on broad remote-control tooling while keeping useful development and staging automation.
How it works
Runner MCP is the local safety boundary. GitHub can be used for source collaboration and, optionally, as a bounded mailbox transport; it is not turned into a mechanism for sending arbitrary shell commands.
The normal authority model is deliberately asymmetric: read-only inspection is easier, mutating staging actions are narrower, higher-risk actions require short-lived local approval, and production mutations remain disabled.
Optional Runner Fabric work-unit bridge
Runner Fabric remains a separate product and orchestration/control-plane owner. When both products run on the same host, Runner MCP can optionally expose a loopback-only transport bridge with three coarse tools — run, inspect and cancel a bounded Fabric work-unit. This lets an AI hand off a whole repository-change workflow without receiving generic GitHub/Git/shell primitives.
The bridge is disabled by default and does not change Runner MCP's authority model. See Optional Runner Fabric bridge.
I just want to use it
You do not need to understand the Python source code for the basic workflow.
Starting with v0.1.1, the shortest persistent install is:
uvx aifordable-runner-mcp ... is also suitable for package discovery and short-lived evaluation, but a persistent tool install is the clearer choice for a self-hosted service with private configuration and autostart.
To install directly from source instead:
Start with QUICKSTART.md for the guided installation.
Connectivity remains loopback-first. runner-mcp setup in public mode records an external HTTPS resource/auth identity only; it does not expose a bind address, install TLS, edit DNS/firewalls, configure a reverse proxy or create a tunnel. runner-mcp guide reports only a generic connectivity category without printing the configured hostname or private URL. For supported OpenAI products, private access can use Secure MCP Tunnel; an external HTTPS reverse proxy remains an operator-managed alternative.
If Runner MCP runs under a dedicated service account while you log in with a separate operator account, install a local operator wrapper. Skip this step when Runner MCP runs under the same account you use interactively:
The wrapper keeps the private configuration with the service account and delegates through sudo; it does not copy credentials into the operator account.
For a user-to-developer path, see docs/USING_AND_EXTENDING.md. Contributors can start with CONTRIBUTING.md.
For the zero-additional-service-cost GitHub mailbox pattern, see docs/GITHUB_MAILBOX_BRIDGE.md. The public package now includes both a transport-neutral processor and a fixed-host GitHub transport; completion feedback and watcher resilience are documented in docs/COMPLETION_FEEDBACK.md and docs/WATCHER_RESILIENCE.md. Bounded multi-project scheduling and capacity controls are documented in docs/CONCURRENCY.md.
Dependency/build/interpreter contract changes are deliberately refused by self-update and require a local bootstrap/manual upgrade; see self-update compatibility.
Runner MCP is developed as an AIfordable project. Public launch readiness is tracked in docs/LAUNCH_READINESS.md. See also the changelog, release checklist and prepared launch copy.
Useful commands:
The emergency stop is intentionally easy to activate and harder to clear.
What works today
Current implemented foundations include:
- authenticated MCP over Streamable HTTP;
- project allow-listing;
- safe project file listing, metadata and paged reads;
- path traversal, symlink and secret-file protection;
- request IDs, rate limiting and audit logging;
- DNS-rebinding protection;
- external operator emergency stop;
- rollback-retention policy using both minimum count and minimum age;
- local read-only retention preview with strict release/backup validation and no deletion authority;
- explicit separation between code rollback and database restore;
- controlled asynchronous test jobs;
- commit-pinned self-update for the canonical Runner MCP project, gated by an unchanged Python/build/dependency compatibility contract, fixed lint/unit validation and internal self-reexec;
- bounded fair multi-project test scheduling with per-project opt-in parallelism;
- safe queue, worker and job observability without infrastructure disclosure;
- allow-listed systemd-user staging service status/start/stop/restart;
- optional private service health checks;
- private PostgreSQL backups with safe metadata listing;
- local read-only PostgreSQL restore preflight without database mutation;
- controlled migration status/apply with mandatory pre-migration backup;
- staging-only release planning and asynchronous deployment jobs;
- clean-Git release archives, atomic activation and health-gated rollback;
- safe release history plus one-step asynchronous staging rollback;
- built-in allow-listed project adapters with safe capability inspection;
- strict MCP tool arguments: unknown fields are rejected rather than ignored;
- short-lived human approval gates for migration, deploy and rollback;
- staging-only mutation policy; production remains read-only;
- private ChatGPT connectivity can use OpenAI Secure MCP Tunnel without an inbound public port;
- predefined test profiles only;
- test timeout, cancellation and process-group cleanup;
- scrubbed, bounded test logs;
- recovery of interrupted test-job metadata after restart;
- interactive setup, status and doctor commands;
- CLI project management without manual YAML editing;
- CLI test-profile management with pytest, Ruff and custom presets;
- non-root local installer and guided Quickstart.
What Runner MCP deliberately does not do
Runner MCP is not intended to provide:
- a general remote shell;
- arbitrary commands supplied by an AI client;
- automatic production database restore;
- database restore execution in the current implementation;
- automatic multi-release rollback cascades;
- unrestricted service control;
- untrusted public-fork execution on a privileged persistent runner.
Production actions remain out of scope until stronger approval and isolation controls are implemented.
Safety model
Runner MCP is built around:
- deny by default;
- explicit project, service and test-profile allow-lists;
- no arbitrary shell as a normal interface;
- no secrets in MCP tool output;
- strict path validation;
- auditable actions;
- least-privilege runtime permissions;
- explicit risk classes for operational tools;
- external operator emergency stop;
- retention confirmation before operator actions;
- one code rollback step per approved action;
- database restore always requiring explicit human approval;
- DNS-rebinding protection tied to the configured MCP resource URL.
See:
- security/SECURITY_BASELINE.md
- security/THREAT_MODEL.md
- security/OPERATOR_SAFETY.md
- security/TEST_EXECUTION.md
Public repository rule
This repository must never contain real infrastructure details.
Do not commit:
- real IP addresses or hostnames;
- internal domains;
- private service endpoints or ports;
- usernames;
- absolute deployment paths from a real installation;
- database endpoints;
- credentials or tokens;
- private keys;
- database dumps or backups.
Public examples use placeholders only. Real values belong in private local configuration or an appropriate secret store.
Controlled test execution
An MCP client may choose only a configured project and named test profile.
A test profile defines the exact executable, exact argument array, project-relative working directory, timeout, log limit and explicitly allowed environment variables.
Commands are launched with shell=False.
Running a test still executes project code. Until stronger sandboxing exists, only trusted repository revisions should be tested.
Rollback philosophy
Code rollback and database recovery are separate operations.
Code releases are retained using both:
- a minimum number of releases;
- a minimum age.
A release is eligible for cleanup only when both conditions permit it.
A single approved rollback action may move back exactly one code release. Runner MCP must stop, health-check and reassess before another rollback.
Database restore is never an automatic side effect of code rollback and always requires explicit human approval.
Development
Target runtime: Python 3.12+.
Core technologies:
- official MCP Python SDK;
- Pydantic;
- PyYAML;
- Starlette;
- Uvicorn;
- pytest;
- Ruff.
The implementation uses Streamable HTTP for MCP.
Do not connect a privileged persistent self-hosted runner to untrusted public pull-request code.
Project status
The current implementation state is tracked in:
Runner MCP v0.1.0 is the first public alpha release. The project remains under active development. The public GitHub mailbox stack now includes protocol-v1 validation, replay lifecycle, fixed-host transport, an incremental restart-safe watcher, a loopback-only MCP executor, bounded concurrent request handling, fail-closed missing-result recovery and a private-config runtime/CLI. Shared-watcher migration, exactly-once completion feedback, clean-Linux demo validation, non-root autostart packaging and privacy-safe connectivity guidance are complete. Ongoing alpha hardening and post-release work are tracked in the roadmap and release checklist.