How to update outdated Samples

Error Message:

Cannot sample for transaction "GET /api/v1/launches -> 200",
because it based on version "abc123" but the loaded samples
are based on version "def456".

Why This Happens

Samples become outdated when you modify your OpenAPI specification:

Adding or removing endpoints
Changing request/response schemas
Modifying path parameters or query parameters
Updating response status codes

The sampler tracks the specification version and detects mismatches to ensure test reliability.

Solution: Regenerate Samples

Step 1: Review Your Changes

Before regenerating, understand what changed in your API.Review endpoints, schemas, and contracts that were modified.

Step 2: Regenerate Samples

Run the init command with the --overwrite flag:

thymian sampler init --overwrite

This will:

Generate new sample data based on the updated specification
Overwrite request.json files with new sample values
Update the version hash in meta.json
Regenerate TypeScript types in types.d.ts
Leaves hook files untouched

Step 3: Review Generated Samples

Check the regenerated samples to ensure they match your expectations and inspect critical request.json files to verify the generated data is appropriate.

Step 4: Customize Samples (If Needed)

If the auto-generated samples don’t fit your needs, customize them manually:

{
  "body": {
    "missionName": "Apollo 11",
    "launchDate": "2026-07-20T20:17:00Z",
    "rocketType": "Saturn V"
  }
}

See How to Customize Request Data for details.

Step 5: Update Hooks (If Necessary)

If your API changes affect authentication or data dependencies, update your hooks. Verify that hooks still work with the new API structure.

Step 6: Run Tests

Verify everything works:

thymian sampler check

Understanding the Version Hash

The version hash is calculated from:

All endpoint definitions (paths, methods, status codes)
Request and response schemas
Security requirements
Server URLs