Freeze Your V1 API With One YAML File

Your V1 API has 200 consumers. Your V2 is in active development. You need different rules for each. Delimit's custom policies let you define exactly what's allowed where.

One YAML file

Create .delimit/policies.yml in your repo:

rules:
  - id: freeze_v1
    name: Freeze V1 API
    change_types:
      - endpoint_removed
      - method_removed
      - field_removed
      - type_changed
    severity: error
    action: forbid
    conditions:
      path_pattern: "^/v1/.*"
    message: "V1 API is frozen. Make changes in V2."

  - id: warn_v2_type_changes
    name: Warn V2 Type Changes
    change_types:
      - type_changed
    severity: warning
    action: warn
    conditions:
      path_pattern: "^/v2/.*"
    message: "Type changed at {path} -- verify client compat."

What you can control

• Path patterns -- apply rules to specific API versions or service paths
• Change types -- target specific breaking change categories (10 available)
• Severity -- error (blocks in enforce mode) or warning (logged only)
• Messages -- custom error messages with path interpolation

Policies are checked in git alongside your spec. They're versioned, reviewable, and auditable — the same workflow as code.

Built-in presets

Don't want to write YAML? Use a preset:

npx delimit-cli init --preset strict   # all violations are errors
npx delimit-cli init --preset default  # balanced
npx delimit-cli init --preset relaxed  # all violations are warnings