/postman:mock -- Create Mock Servers

Create Postman mock servers from your collections or API specs. Get a working mock URL for frontend development, integration testing, or demos.

Prerequisites

Postman MCP Server must be configured. If MCP tools fail, tell the user to run /postman:setup.

Workflow

Step 1: Find the Source

Option A: From existing collection

1. Call getCollections to list available collections
2. Select the target collection
3. Call getCollection (full model) to check its contents

Option B: From local spec

1. Find OpenAPI spec in the project (**/openapi.{json,yaml,yml}, **/swagger.*)
2. Import it first:
   • Call createSpec with the spec content
   • Call generateCollection from the spec (async, poll getGeneratedCollectionSpecs for completion)

Step 2: Check for Response Examples

Mock servers serve example responses. Check if the collection has saved response examples.

Call getCollection and inspect requests for saved responses.

If examples are missing:

Your collection doesn't have response examples. Mock servers
need these to know what to return.

I'll generate realistic examples from your schemas and add them
to the collection.

For each request without examples:

1. Call getCollectionRequest to get the request definition and any schema info
2. Generate a realistic example response based on the schema, endpoint name, and HTTP method
3. Call createCollectionResponse to save the example with:
   • Appropriate status code (200 for GET, 201 for POST, 204 for DELETE)
   • Realistic response body with sample data
   • Correct Content-Type header

Step 3: Create Mock Server

Call createMock with:

• collectionId: The collection to mock
• name: <api-name> Mock
• environment: Environment ID if applicable
• isPublic: false by default (private mock requires Postman API key header)

Step 4: Present Mock URL

Mock server created: "Pet Store API Mock"
  URL: https://<mock-id>.mock.pstmn.io
  Status: Active
  Visibility: Private (requires x-api-key header)

  Try it:
    curl -H "x-api-key: $POSTMAN_API_KEY" https://<mock-id>.mock.pstmn.io/pets
    curl -H "x-api-key: $POSTMAN_API_KEY" https://<mock-id>.mock.pstmn.io/pets/1

  The mock serves the example responses from your collection.
  Update examples in Postman to change mock behavior.

Step 5: Integration Snippets

Provide code to integrate the mock into the user's project:

Quick integration:

  # Add to your .env file
  API_BASE_URL=https://<mock-id>.mock.pstmn.io
  POSTMAN_MOCK_API_KEY=<your-postman-api-key>

  # In your code
  const API_URL = process.env.API_BASE_URL || 'https://<mock-id>.mock.pstmn.io';

Step 6: Publish (optional)

If the user wants the mock publicly accessible (no API key required):

• Call publishMock to make it publicly available
• Useful for demos, hackathons, or public documentation

To revert to private:

• Call unpublishMock

Error Handling

Error	Response
Collection not found	"I didn't find that collection. Run /postman:search to see available collections."
No examples to mock	"This collection has no response examples and no schemas to generate from. Add example responses in Postman first."
Mock creation failed	"Mock server creation failed. Make sure the collection has at least one request with a saved response example."
Auth failure	"Postman returned 401. Your API key may be expired. Run /postman:setup to reconfigure."