Configuration

Prelint works without any configuration. Install the GitHub App, and every PR gets reviewed. Add a prelint.json to your repository root when you want to exclude files, add custom rules, or control what context the review engine sees.

Quick start

Create a prelint.json file in your repository root:

prelint.json

{
  "version": 1,
  "exclude_authors": ["dependabot[bot]", "renovate[bot]"]
}

That's it. Prelint indexes markdown files in your repo automatically and reviews every PR.

Configuration priority

Settings are merged from multiple sources. Higher-priority sources override lower ones:

Built-in defaults: sensible starting configuration.
Organization settings: set in the Prelint dashboard for all repos.
Project settings: scoped to a project in the dashboard.
Repository settings: set in the dashboard for a specific repo.
prelint.json: highest priority. Lives in the repo, versioned with your code.

Version your config

Using prelint.json means your configuration is reviewed in PRs alongside your code. Teams can discuss and approve config changes like any other code change.

Full schema reference

Property	Type	Default	Description
version	number	1	Schema version. Always set to 1.
exclude_authors	string[]	["dependabot[bot]", "renovate[bot]", "github-actions[bot]", "snyk-bot"]	PR authors to skip. Supports GitHub bot format.
ignore_patterns	string[]	[]	Glob patterns for files to ignore in reviews.
rules	Rule[]	[]	Custom review rules. See Rules section below.
context_files	string[]	[]	Additional files to include as review context.
output.comments	boolean	true	Post inline comments on the PR diff.
output.check_run	boolean	true	Create a GitHub check run with review summary.

Ignore patterns

Use glob syntax to exclude files from reviews. Patterns are matched against the file path relative to the repository root.

prelint.json

{
  "ignore_patterns": [
    "docs/**",
    "**/*.test.ts",
    "migrations/**",
    "*.generated.ts",
    "!docs/api/**"
  ]
}

Built-in exclusions (always ignored):

*.lock, *-lock.*: lock files
vendor/**, node_modules/**: vendored dependencies
*.min.js, *.min.css: minified assets
*.png, *.jpg, *.gif, *.svg, *.ico: images
*.woff, *.woff2, *.ttf, *.eot: fonts

Prefix a pattern with ! to negate it (force-include a file that would otherwise be ignored).

Rules

Custom rules let you enforce project-specific requirements beyond what specs cover. Each rule has a name and a description that the review engine uses.

prelint.json

{
  "rules": [
    {
      "name": "No direct database queries in handlers",
      "description": "All database access must go through the repository layer. Handler functions should not import or use database clients directly."
    },
    {
      "name": "Feature flags for new endpoints",
      "description": "New API endpoints must be wrapped in a feature flag. Use the featureFlags.isEnabled() check before executing endpoint logic."
    }
  ]
}

Rules are included in the review context alongside specs. The review engine evaluates every diff change against all active rules.

Context files

Context files provide additional information to the review engine without being formal specs. Use them for:

API documentation that the code should match
Database schemas that inform business logic
Design system guidelines for frontend code
Third-party integration docs that constrain implementation

prelint.json

{
  "context_files": [
    "docs/api-reference.md",
    "docs/database-schema.md",
    "ARCHITECTURE.md"
  ]
}

Context files differ from specs: specs define what should be built, context files provide background information that helps the review engine understand your codebase.

Complete example

prelint.json

{
  "version": 1,
  "exclude_authors": [
    "dependabot[bot]",
    "renovate[bot]"
  ],
  "ignore_patterns": [
    "docs/**",
    "**/*.test.ts",
    "**/*.spec.ts",
    "migrations/**"
  ],
  "rules": [
    {
      "name": "Repository pattern",
      "description": "All database access must use the repository pattern. No direct ORM calls in service or handler files."
    }
  ],
  "context_files": [
    "ARCHITECTURE.md",
    "docs/api-reference.md"
  ],
  "output": {
    "comments": true,
    "check_run": true
  }
}