See Delimit in Action

Install, detect breaking changes, enforce policies — in 60 seconds.

Try the Diff Engine

One of 106 tools — edit the specs below and see breaking changes detected live.

For the full experience, install Delimit into your AI coding assistant:

npx delimit-cli setup

Paste two OpenAPI specs below and see breaking changes detected instantly. The sample specs include 3 breaking changes for you to explore.

Base Spec (before)OpenAPI 3.x YAML

openapi: "3.0.3"
info:
  title: Pet Store API
  version: "1.4.0"
paths:
  /pets:
    get:
      summary: List all pets
      operationId: listPets
      parameters:
        - name: limit
          in: query
          required: false
          schema:
            type: integer
      responses:
        "200":
          description: A list of pets
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: "#/components/schemas/Pet"
    post:
      summary: Create a pet
      operationId: createPet
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: "#/components/schemas/NewPet"
      responses:
        "201":
          description: Pet created
  /pets/{petId}:
    get:
      summary: Get a pet by ID
      operationId: getPet
      parameters:
        - name: petId
          in: path
          required: true
          schema:
            type: string
      responses:
        "200":
          description: A single pet
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Pet"
    delete:
      summary: Delete a pet
      operationId: deletePet
      parameters:
        - name: petId
          in: path
          required: true
          schema:
            type: string
      responses:
        "204":
          description: Pet deleted
components:
  schemas:
    Pet:
      type: object
      required:
        - id
        - name
        - status
      properties:
        id:
          type: string
          description: Unique identifier
        name:
          type: string
        status:
          type: string
          enum:
            - available
            - pending
            - adopted
    NewPet:
      type: object
      required:
        - name
      properties:
        name:
          type: string
        tag:
          type: string

Changed Spec (after)OpenAPI 3.x YAML

openapi: "3.0.3"
info:
  title: Pet Store API
  version: "1.5.0"
paths:
  /pets:
    get:
      summary: List all pets
      operationId: listPets
      parameters:
        - name: limit
          in: query
          required: false
          schema:
            type: integer
      responses:
        "200":
          description: A list of pets
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: "#/components/schemas/Pet"
    post:
      summary: Create a pet
      operationId: createPet
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: "#/components/schemas/NewPet"
      responses:
        "201":
          description: Pet created
  /pets/{petId}:
    get:
      summary: Get a pet by ID
      operationId: getPet
      parameters:
        - name: petId
          in: path
          required: true
          schema:
            type: string
      responses:
        "200":
          description: A single pet
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/Pet"
components:
  schemas:
    Pet:
      type: object
      required:
        - id
        - name
        - status
      properties:
        id:
          type: integer
          description: Unique identifier
        name:
          type: string
        status:
          type: string
          enum:
            - available
            - adopted
    NewPet:
      type: object
      required:
        - name
      properties:
        name:
          type: string
        tag:
          type: string