Postman Cheatsheet - API Debugging Tool Reference

A single curl proves nothing about auth edge cases or response shapes across environments. Postman turns requests into an environment-aware, scriptable workflow. This reference covers building requests, environment and global variables, test assertions with pm.test, pre-request scripts and dynamic data, plus running whole collections and spinning up Mock servers. Use it when you need repeatable tests for many endpoints, not one-off probes. After reading you automate assertions and re-run suites across dev/staging/prod.

Dev Tools·35 commands·Last updated 2026-07-21

Request Building 7

GET {{base_url}}/api/users

GET request

POST {{base_url}}/api/users

POST request

PUT {{base_url}}/api/users/1

PUT request

DELETE {{base_url}}/api/users/1

DELETE request

Headers: Content-Type: application/json

Set a request header

Body → raw → JSON

JSON request body

Authorization: Bearer {{token}}

Bearer Token auth

Environment Variables 6

{{base_url}}

Reference an environment variable

pm.environment.set("token", "xxx")

Set an environment variable

pm.environment.get("token")

Get an environment variable

pm.environment.unset("token")

Unset an environment variable

pm.globals.set("key", "value")

Set a global variable

pm.variables.get("key")

Get a variable (env/global)

Test Scripts 6

pm.test("Status is 200", () => { pm.response.to.have.status(200) })

Status code test

pm.expect(pm.response.json().name).to.eql("Alice")

JSON field test

pm.response.to.be.json

Response is JSON

pm.response.to.have.header("Content-Type")

Response header test

pm.expect(pm.response.responseTime).to.be.below(500)

Response time test

const json = pm.response.json()

Parse response JSON

Pre-request Scripts 4

pm.request.headers.add({key: "X-Token", value: "xxx"})

Dynamically add a request header

pm.request.body.update("new body")

Modify the request body

const timestamp = Date.now(); pm.environment.set("ts", timestamp)

Generate a timestamp

pm.request.url.addQueryParams({page: 1})

Add a query parameter

Collections & Runner 7

Collection Runner

Run a collection in batch

New Runner

New runner

Set Data File (CSV/JSON)

Data-driven testing

Delay: 1000ms

Request interval

Iterations: 10

Iteration count

Export Collection

Export collection

Import from cURL / OpenAPI

Import from cURL / OpenAPI

Mock & Docs 5

Mock Server

Create a Mock server

Example Responses

Save example responses

Documentation

Generate API docs

Publish Documentation

Publish docs

Monitor

Monitor

Tips

Variables come in Environment (current) and Global; put secrets in Environment.
Collection Runner plus a CSV data file enables data-driven testing.
Mock Server suits parallel frontend dev when the backend isn't ready yet.

Official References

Each command links to its official documentation below, so you can verify the latest usage and read deeper.

Postman Docs

Maintained by LaoHand

Publicly updated on Jul 21, 2026, continuously proofread against official docs.

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