Max Owners + CODEOWNERS Collector

✓ Guardrail ↓ Collector Stable Repository And Ownership

Enforce Max Owners using data collected by CODEOWNERS Collector. Automatically check repository and ownership standards on every PR.

Guardrail: Flags CODEOWNERS rules with too many owners. Excessive owners often means diffused responsibility where nobody truly owns the code. Configurable via the max_owners_per_rule input.

Data Source: Parse CODEOWNERS files to collect structured ownership data including rules, owner types, and catch-all coverage. Enables enforcement of code ownership standards across your organization.

Get Started View on GitHub

How CODEOWNERS Collector Powers This Guardrail

The CODEOWNERS Collector gathers metadata from your vcs systems. This data flows into Lunar's Component JSON, where the Max Owners guardrail evaluates it against your standards.

When enabled, this check runs automatically on every PR and in AI coding workflows, providing real-time enforcement with actionable feedback.

↓ CODEOWNERS Collector Gathers Data Collector

Extracts metadata from code, configs, and tool outputs

{ } Component JSON

Data centralized in structured format for evaluation

✓ Max Owners Checks Guardrail

Pass/fail result with actionable feedback in PRs

Quick Start Configuration

Add both the collector and policy to your lunar-config.yml to enable this guardrail.

📄 lunar-config.yml

# Step 1: Enable the CODEOWNERS Collector
collectors:
  - uses: github://earthly/lunar-lib/collectors/codeowners@v1.0.0
    # with: ...

# Step 2: Enable the CODEOWNERS Guardrails
policies:
  - uses: github://earthly/lunar-lib/policies/codeowners@v1.0.0
    include: [max-owners]
    # with: ...

What CODEOWNERS Collector Collects

This collector gathers the following data that the Max Owners guardrail evaluates.

Collector code

`codeowners`

Scans the repository for a CODEOWNERS file in standard locations (CODEOWNERS, .github/CODEOWNERS, docs/CODEOWNERS) and parses its contents. Extracts ownership rules, validates syntax, classifies owners as teams vs individuals, and detects catch-all rules. Writes structured data to .ownership.codeowners.

Example Data Flow

Here's an example of the data that CODEOWNERS Collector writes to the Component JSON, which Max Owners then evaluates.

{ } component.json From CODEOWNERS Collector

{
  "ownership": {
    "codeowners": {
      "exists": true,
      "valid": true,
      "path": ".github/CODEOWNERS",
      "errors": [],
      "owners": ["@acme/backend-team", "@acme/platform-team", "@jdoe"],
      "team_owners": ["@acme/backend-team", "@acme/platform-team"],
      "individual_owners": ["@jdoe"],
      "rules": [
        {
          "pattern": "*",
          "owners": ["@acme/platform-team"],
          "owner_count": 1,
          "line": 3
        },
        {
          "pattern": "/src/backend/",
          "owners": ["@acme/backend-team", "@jdoe"],
          "owner_count": 2,
          "line": 6
        }
      ]
    }
  }
}

Configuration Options

CODEOWNERS Collector Inputs

Input	Required	Default	Description
`paths`	Optional	`CODEOWNERS,.github/CODEOWNERS,docs/CODEOWNERS`	Comma-separated list of CODEOWNERS file paths to check (first match wins)

CODEOWNERS Guardrails Inputs

Input	Required	Default	Description
`min_owners_per_rule`	Optional	`2`	Minimum number of owners required per CODEOWNERS rule (for min-owners check)
`max_owners_per_rule`	Optional	`10`	Maximum number of owners allowed per CODEOWNERS rule (for max-owners check)

Learn More

Guardrail · CODEOWNERS Guardrails Max Owners View all compatible integrations

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Collector CODEOWNERS Collector View full documentation

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