Postman Plugin

Powering API engineering for agents

The Postman plugin brings filesystem-first API development and organization-wide API context to coding agents. It enables agents to design, mock, test, document, monitor, and ship APIs directly from Claude Code, Cursor, and Codex. Every operation produces inspectable files or CLI commands that fit naturally into Git and CI, while the Postman Context Graph helps agents understand dependencies, ownership, runtime behavior, and the likely impact of a change.

Install · Highlights

Install

Install Postman in every compatible coding agent detected on your machine:

npx @postman/postman-plugin

One command configures Claude Code, Codex, Cursor, Factory Droid, Kimi Code, OpenCode and Pi. Run it again to update, status to see what's installed, and remove to uninstall; --agent <id> limits any of them to one agent.

You can also use the following commands to install individually:

Claude Code

View Postman on Claude Plugins

claude plugin marketplace add anthropics/claude-plugins-official
claude plugin install postman@claude-plugins-official

The first command registers Anthropic's official marketplace, which a fresh Claude Code doesn't have until an interactive session gets past sign-in. It does nothing where the marketplace is already registered.

Codex

View Postman on ChatGPT Plugins

codex plugin marketplace add postmanlabs/postman-plugin
codex plugin add postman@postman

Cursor

View Postman on the Cursor Marketplace

/add-plugin postman

Factory Droid

droid plugin marketplace add https://github.com/postmanlabs/postman-plugin.git
droid plugin install postman@postman-plugin --scope user

droid plugin marketplace update postman-plugin, then droid plugin update postman@postman-plugin --scope user, updates it. Sign in to Postman's MCP server with /mcp inside a Droid session.

Kimi Code

Inside a Kimi Code session:

/plugins install https://github.com/postmanlabs/postman-plugin/tree/main

Then run /new to start a session with the plugin. Run the same command again, then /new, to update; /plugins remove postman removes it. Sign in to Postman's MCP server with /mcp-config login plugin-postman:postman.

OpenCode

opencode plugin add github:postmanlabs/postman-plugin

That is OpenCode 2.0.4 or later. On OpenCode 1.14.33 or later the command is opencode plugin --global github:postmanlabs/postman-plugin. opencode/README.md has how to update and remove it, and the older clone-and-loader install.

Pi

View Postman in Pi's package gallery

pi install npm:@postman/postman-plugin

pi update npm:@postman/postman-plugin updates it. Sign in to Postman's MCP server with /mcp login postman inside a Pi session. The shell's pi mcp login doesn't load extensions, so it reports no server named postman.

Highlights

Filesystem-first API development

All postman resources have a filesystem representation, so your agent can work with the API ecosystem through the interface it understands best: files. API specifications, collections, environments, examples, mocks, documentation, and Flows can live beside the application code.

The git-native v3 collection schema makes this especially agent-friendly. A collection is a directory tree under postman/collections/, where every request, folder definition, and saved example is its own YAML file. Environments use the same file-first model under postman/environments/. HTTP, GraphQL, gRPC, WebSocket, Socket.IO, MQTT, MCP, and LLM requests all have defined schemas the agent can follow.

That means the agent can:

• Read or change one request without rewriting a large collection export.
• Generate requests and examples directly from an API specification.
• Produce small, reviewable Git diffs and resolve changes with normal code review workflows.
• Lint and test the files locally before anything is shared with a Postman workspace.

Context Graph: know what breaks before you make a change

A repository can show what an endpoint calls, but rarely who calls it, whether those consumers are active in production, where they are deployed, or which team owns them. The Context Graph fills that gap with a private, authenticated, organization-wide map of your API ecosystem.

It reconciles signals from the systems where API knowledge already lives:

• Postman workspaces: specifications, collections, monitors, and mocks
• GitHub: repositories, API definitions, and source-level call sites
• New Relic: deployments, runtime traffic, latency, errors, and telemetry

The api-discovery skill lets the agent start with the thing you plan to change and ask one natural-language question:

postman context-graph ask "What could break if we change the billing API?" --wait

The graph discovers the surrounding scope—including repositories that are not checked out locally—before the agent starts editing code. It refreshes nightly as services, deployments, ownership, and runtime relationships change.

In Postman's controlled benchmark across 468 repositories, starting with this map used up to 74% fewer tokens, 52% fewer tool calls, and 72% lower cost. Accuracy also improved in 18 of 21 scored prompt-model pairs. Most graph queries completed in roughly 20–40 seconds. Read the methodology and results in Introducing the Context Graph API: One Map of Your API Ecosystem.

File-first API mocks

The api-mocking skill creates a working mock from an OpenAPI specification or collection and stores the implementation beside the API code. The agent can run it locally, add success and failure scenarios, and test consumers without waiting for the real service to be ready or available.

The mock stays local until you choose to push and deploy it. When teammates or external systems need access, the same mock can become a durable hosted URL without rebuilding it in another tool.

Develop against simulated dependencies

The api-simulation skill is the local loop for a service change: find every dependency the service calls, mock each one (reusing the owning team's mock when they publish one), serve them on one port from one .sim.yaml, run the real service against them, test, and push. It needs Postman CLI 1.70.0 or later:

postman simulation run postman/simulations/orders-dev.sim.yaml --port 4900

The service under test is never mocked. It runs for real, so a passing run shows the change works against what the mocks model; it doesn't replace a run against the real upstreams. The simulation can also run in CI, and any dependency can take injected latency, error, rate-limit, or chaos conditions to exercise failure paths.

How Postman builds context

Work done in a Postman folder produces artifacts: collection runs, lint results, request history, mock deployments. When that folder is connected to a Postman workspace after postman init, those artifacts are published to it as they are produced. The workspace persists that context for future work and enables teammates, reviewers, and other agents to share and build on what the agent did.

What each command contributes to the connected workspace:

Publishing happens by default. To change this workflow, you can set --report-events=false per invocation.

Anonymous usage counts

The CLI records command usage surface — a minimal, unauthenticated count with no workspace, user, or payload attached.

The MCP fallback

The plugin registers Postman's hosted MCP server as a fallback for when the CLI cannot run. MCP tool calls reach Postman by design and are not governed by the CLI flags above; skip installing the MCP server if you do not want that path.

License

Apache-2.0 — see LICENSE.