# Bastion

> Agentic code review built as single-concern reviewers: declarative, human-authored fitness functions over every changeset that aggregate into one merge gate that fails closed.

Bastion is a Rust CLI and GitHub CI adapter. You declare reviewers in `.bastion.yaml`; matched reviewers run over a changeset and return structured verdicts that Bastion aggregates into a single merge decision. Humans govern the reviewer policy rather than reviewing every diff.

## User guide

- [Bastion user guide](https://bastion.jessica.black/guide/index.md): Agentic code review for a world where agents write all of the code.
- [Introduction](https://bastion.jessica.black/guide/introduction.md): Why Bastion exists, and the one idea you need to hold in your head.
- [Getting started](https://bastion.jessica.black/guide/getting-started.md): Install Bastion, write one reviewer, and run your first review.
- [Concepts](https://bastion.jessica.black/guide/concepts.md): The vocabulary Bastion runs on: reviewers, triggers, modes, verdicts, and the merge gate.
- [Authoring reviewers](https://bastion.jessica.black/guide/authoring-reviewers.md): The registry schema in full, and how to write a reviewer that stays sharp.
- [The local workflow](https://bastion.jessica.black/guide/local-workflow.md): Running bastion review for real: the loop, the two output formats, exit codes, and inspecting what was saved.
- [Continuous integration](https://bastion.jessica.black/guide/continuous-integration.md): Promoting your reviewers into GitHub Actions: one required check and per-author billing.
- [Governance](https://bastion.jessica.black/guide/governance.md): Keeping humans at the policy layer: protecting the registry, the escape-to-improvement loop, and what Bastion deliberately does not guarantee.

## Optional

- [Full guide as one file](https://bastion.jessica.black/llms-full.txt): every chapter concatenated for a single fetch.
- [Source repository](https://github.com/jssblck/bastion): the developer guide, reviewer registry, and code.