postman2pytest 1.1.0

Convert Postman Collection v2.1 JSON files into executable pytest test suites

postman2pytest

Convert a Postman Collection v2.1 JSON file into a ready-to-run pytest test suite. One command.

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postman2pytest --collection my_api.json --out tests/test_api.py
BASE_URL=https://api.example.com pytest tests/test_api.py -v

Why

Postman collections document your API. postman2pytest turns that documentation into executable regression tests that run in CI. No manual rewriting, no drift.

Install

pip install postman2pytest

Or from source:

git clone https://github.com/golikovichev/postman2pytest
cd postman2pytest
pip install -e .

Usage

postman2pytest \
  --collection data/my_api.postman_collection.json \
  --out generated_tests/test_api.py

Then run the generated tests:

BASE_URL=https://staging.example.com pytest generated_tests/test_api.py -v

Options

Flag	Required	Description
--collection	✅	Path to Postman Collection v2.1 JSON
--out	✅	Output path for generated pytest file
--base-url	❌	Tip printed after generation (does not override env var)
--filter-folder	❌	Generate tests only for the named Postman folder

To regenerate tests for one folder, pass its Postman folder name:

postman2pytest \
  --collection data/my_api.postman_collection.json \
  --out generated_tests/test_users.py \
  --filter-folder Users

Examples

Generate tests for a single folder

The bundled data/sample_collection.json file includes a Users folder and one top-level Health check request. Generating from the whole collection creates three tests:

postman2pytest \
  --collection data/sample_collection.json \
  --out /tmp/test_all.py

Generated 3 test(s) -> /tmp/test_all.py

The generated file contains tests with folder-prefixed names:

def test_users_get_get_all_users():
def test_users_post_create_user():
def test_get_health_check():

To generate only the requests from the Users folder, pass --filter-folder. Folder matching is case-insensitive, so Users, users, and USERS all match the same folder:

postman2pytest \
  --collection data/sample_collection.json \
  --out /tmp/test_users.py \
  --filter-folder Users

Generated 2 test(s) -> /tmp/test_users.py

The filtered output contains only the tests from that folder:

def test_users_get_get_all_users():
def test_users_post_create_user():

How It Works

1. Parse: reads the Postman Collection JSON, flattens nested folders into a flat request list
2. Extract: captures method, URL, headers, body, and expected status from pm.response.to.have.status() test scripts
3. Generate: renders a Jinja2 template into a .py file with one def test_*() per request

Variable substitution

Postman variables {{base_url}} become ENV_base_url in the URL, resolved at runtime via the BASE_URL environment variable.

Generated output example

Given a Postman request GET {{base_url}}/api/v1/users with a test asserting status 200, the output is:

def test_get_users():
    """GET ENV_base_url/api/v1/users"""
    url = f"{BASE_URL}/api/v1/users"
    headers = {}
    response = requests.get(url, headers=headers)
    assert response.status_code == 200, (
        f"Expected 200, got {response.status_code}: {response.text[:200]}"
    )

Supported features

• ✅ Postman Collection v2.1 (v2.0 accepted with a warning)
• ✅ Nested folders → flattened with folder prefix in test name
• ✅ GET, POST, PUT, DELETE, PATCH, HEAD, OPTIONS
• ✅ Request headers (disabled headers excluded)
• ✅ Raw JSON body
• ✅ Expected status from pm.response.to.have.status(N) test scripts
• ✅ Falls back to 200 when no status assertion found
• ✅ Malformed items skipped with a warning. Rest of collection still generated

Limitations

Honest scope so you know what to expect before pointing the tool at a real collection.

• ❌ Postman environments are not read. {{baseUrl}} and friends are passed through verbatim into the generated url strings. Set the BASE_URL env var at test time, or post-process the file to swap in the values you care about.
• ❌ Pre-request scripts are skipped. Auth that depends on pm.sendRequest to grab a token before each call (e.g. OAuth client-credentials flows refreshing per request) needs manual translation into a pytest fixture.
• ❌ Test scripts beyond a status assertion are dropped. Only pm.response.to.have.status(N) is extracted; chai-style body shape checks, custom JS, and pm.variables.set(...) calls do not survive the conversion.
• ❌ Form-data and urlencoded bodies are not generated yet. Only raw JSON bodies are written into the test file. Multipart uploads, file attachments, and form fields are recognised by the parser but left out of the rendered request call. Tracked in issue #1.
• ❌ Cookies, certificates, and per-request proxy settings are ignored.
• ⚠ Variable substitution is shallow. Path variables (/users/:id) become {id} placeholders; collection-level variables are not resolved.
• ⚠ Generated BASE_URL defaults to an empty string. Tests that hit a full URL in the Postman item still resolve, but bare path items will fail until the env var is set.

If a missing feature is blocking you, please open an issue with a redacted slice of the collection that demonstrates it.

Roadmap

Short list of what is next, roughly in priority order. Tracked in detail on the issues board.

• Form-data and urlencoded body support: currently parsed but not rendered. Blocking most file-upload and OAuth-token-endpoint test cases. (#1)
• Pre-request script translation, scoped scope: surface the script, even as a pytest.fixture stub, so the operator does not lose the auth context silently.
• --ai-edges mode: opt-in pass that asks an LLM to fill in edge cases (boundary numbers, missing required fields, type-confusion payloads) on top of the deterministic happy-path tests. (#2)
• Environment file ingestion: accept Postman environment JSON exports and write a matching conftest.py so {{baseUrl}} and similar resolve through pytest variables.
• Allure step annotations toggle: --allure flag that wraps each generated test in allure.step(...) blocks so the report shows the Postman folder structure.

Contributions to any of the above are welcome. See CONTRIBUTING.md for the workflow.

Running tests

pip install pytest
pytest tests/ -v

Related projects and patterns

Once postman2pytest has generated your suite, the next questions are usually «how do I structure fixtures across all these requests» and «how do I run them under async with shared auth state». The tessl-labs/pytest-api-testing skill on the Tessl Registry collects the conventions that worked for that follow-on layer: httpx AsyncClient setup, conftest.py fixture shape, database isolation, parametrize patterns for edge cases, and auth-flow handling. Useful reference if your generated tests grow beyond the request-by-request shape this tool emits.

Sister projects in the same workspace:

• secure-log2test: same idea but the input is Kibana / Elasticsearch JSON logs instead of Postman collections.
• pytest-conversational: pytest plugin for multi-turn dialogue testing.

Contributing

See CONTRIBUTING.md.

Changelog

See CHANGELOG.md for release notes.

License

MIT. See LICENSE.