API Test Automation

API Test Automation

Overview

Use this skill to turn API or interface documentation into an executable automated test suite. Always carry the work through end-to-end: understand the API spec, generate complete test cases, wire pre-request and post-assertion logic, execute the suite in the requested environment, and emit a complete report.

Workflow

1. Identify the input artifacts.
2. Normalize the execution environment.
3. Generate the test workspace and test cases.
4. Add pre-request scripts and post-response assertion scripts.
5. Execute the suite in the requested environment.
6. Produce the report and call out gaps or assumptions.

Step 1: Identify the Input Artifacts

Accept any of these as the source of truth:

• OpenAPI or Swagger JSON or YAML
• Postman collection or environment exports
• Markdown, Word, PDF, spreadsheet, or plain-text API documentation
• Tables that describe endpoints, methods, headers, parameters, request bodies, and expected responses

Before generating tests, extract at least:

• base URL or environment-specific host mapping
• authentication mechanism
• endpoint path and HTTP method
• request parameters, headers, and body schema
• expected status codes and business assertions
• setup or dependency relationships between endpoints

If the documentation is partial, continue by making explicit assumptions and record them in the final report.

Step 2: Normalize the Execution Environment

Read environment-contract.md when the user provides runtime or environment details or asks to execute the generated suite.

Capture these items before execution:

• runner choice: postman, newman, pytest, or another user-mandated runner
• base URL and environment name
• auth secrets or auth injection method
• common headers and variables
• setup or teardown hooks
• report output path

Prefer these execution strategies:

• Use newman when the user environment already relies on Postman collections or JavaScript test scripts.
• Use pytest plus requests when the user wants Python-based suites or the environment clearly supports Python better.
• Follow the user-required runner if they specify one.

Step 3: Generate the Test Workspace and Cases

Run scripts/prepare_test_workspace.py to create a stable workspace skeleton before filling in test logic.

Example:

python scripts/prepare_test_workspace.py --output C:\work\api-test-output --runner postman --env-name sit

Then populate the generated workspace with:

• endpoint-by-endpoint happy-path cases
• validation and error cases for required fields, data types, bounds, and permissions
• dependency-chain cases for create, query, update, delete, or equivalent flows
• data-driven variants when the documentation exposes enumerations or boundary values

Always create or update case-manifest.json so the report stage can map results back to endpoints and coverage.

Step 4: Add Pre-request and Post-assertion Logic

Use templates from assets/templates/ when you need a quick starting point.

Pre-request logic should handle things like:

• auth token acquisition and refresh
• timestamp or signature generation
• shared headers or trace IDs
• setup requests and variable extraction

Post-response assertion logic should validate both transport and business semantics:

• HTTP status code
• response time or basic performance budget when required
• required fields and schema fragments
• business codes or messages
• cross-step state propagation

Keep environment-sensitive values in config or env files rather than hard-coding them into each case.

Step 5: Execute the Suite

If the user asks to run the suite, execute it in the provided environment after confirming the runner and prerequisites from the available local context.

Execution checklist:

• verify required CLI or runtime exists (newman, node, python, pytest, and so on)
• inject environment variables or environment files
• run the generated suite from the generated workspace
• capture raw stdout or stderr and machine-readable result artifacts when possible
• do not silently skip failed setup steps; report them

If the environment is missing a dependency, report the exact blocker and, when appropriate, suggest the minimal install command.

Step 6: Produce the Report

Run scripts/build_test_report.py after execution to generate a human-readable summary and machine-readable JSON report.

Example:

python scripts/build_test_report.py --manifest C:\work\api-test-output\case-manifest.json --results-dir C:\work\api-test-output\reports --output-md C:\work\api-test-output\reports\test-report.md --output-json C:\work\api-test-output\reports\test-report.json

The final report should include:

• environment summary
• source artifacts used
• generated suite summary
• total, passed, failed, and skipped counts
• per-case failure details
• endpoint coverage or uncovered items
• assumptions, blockers, and follow-up recommendations

Resources

scripts/prepare_test_workspace.py

Create a reusable output skeleton with config, report, and script directories plus a starter case-manifest.json.

scripts/build_test_report.py

Merge execution artifacts into a complete Markdown and JSON report.

references/environment-contract.md

Read when runtime or environment details are provided or when deciding how to execute the generated tests.

references/report-contract.md

Read when you need the expected report sections or result-file shape.

assets/templates/

Use starter templates for environment config, pre-request script, post-assertion script, and test-plan notes. Copy and adapt them instead of re-creating boilerplate.