OpenPost
Provides interoperability with Postman Collection v2.1.0, including import/export, legacy Postman scratch-pad schema inspection, and reversible hosts-file blocking to keep legacy Postman offline.
Click on "Deploy Server".
Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state.
In the chat, type
@followed by the MCP server name and your instructions, e.g., "@OpenPostimport my Postman collection from ~/Downloads/API.postman_collection.json"
That's it! The server will respond to your query, and you can continue using it as needed.
Here is a step-by-step guide with screenshots.
OpenPost
๐ Why OpenPost?
In late 2023, Postman deprecated and removed the beloved offline Scratch Pad, mandating cloud-synced accounts and forcing all API test traffic, collections, and sensitive credentials through external cloud servers.
OpenPost is a clean-room, open-source replacement designed from the ground up to restore the speed, privacy, and simplicity of local API testing:
Zero Cloud Mandate: Stored 100% locally on your machine in human-readable flat JSON files and SQLite.
100% Postman Collection v2.1.0 Interoperability: Flawless import and round-trip export compatible with Postman schemas.
Agent-Operable via MCP: Exposes 23 structured Model Context Protocol (MCP) tools so AI agents (Antigravity, Claude, Cursor, Codex) can browse, author, execute, and verify APIs autonomously.
JavaScript Script Engine (
pm.*): Full pre-request and test script execution sandbox with Chai-compatiblepm.test()andpm.expect()assertions.Dual Desktop Options: Ships with both a zero-wait native browser-app desktop launcher and a compiled Tauri v2 standalone application with Windows MSI and NSIS installers.
Related MCP server: Postman MCP Server
๐ฌ Clean-Room Reverse-Engineering (REA Package)
OpenPost was built through clean-room schema mapping and protocol analysis of Postman's legacy and modern formats using our built-in rea (Reverse Engineer Anything) package:
โโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโ
โ REA REVERSE-ENGINEERING PHASES โ
โโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโค
โ Phase 1: Legacy "Scratch Pad" Autopsy (Postman v9.x / v10.14) โ
โ โข Extracted app.asar (313MB) to map offline architecture without root. โ
โ โข Discovered the 10 core IndexedDB stores (collections, requests, โ
โ environments, globals, history, scratchpad, workspaces, etc.). โ
โ โข Decoded Electron IPC event bus (PM_EB_INT_BROADCAST_MAIN / REND). โ
โ โข Implemented the 7 legacy schema migration rules (dataMode: "raw", โ
โ rawModeData, headerData, compound UID decomposition, etc.). โ
โโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโค
โ Phase 2: Cloud Sync & Export Mechanics โ
โ โข Analyzed HAR network waterfall captures for Ctrl+S save requests. โ
โ โข Deconstructed runtime variable interpolation & URL path variables. โ
โ โข Built bidirectional adapter: UI/IPC state <-> Collection v2.1.0. โ
โโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโโ๐ Architecture
flowchart TB
subgraph Clients["Clients and Autonomous Agents"]
Agent["AI Agents<br/>(Antigravity / Claude / Cursor)"]
UI["Dark-Mode WebUI<br/>(Linear / Postman Style)"]
Desktop["Desktop Application<br/>(Tauri v2 / WebView2)"]
end
subgraph OpenPost["OpenPost Core Engine"]
MCP["Model Context Protocol Server<br/>(backend/mcp_server.py - 23 Tools)"]
API["FastAPI REST Server<br/>(backend/main.py)"]
Parser["Postman v2.1.0 Parser and Exporter<br/>(backend/collection_parser.py)"]
Engine["HTTP Dispatcher and Var Engine<br/>(backend/request_engine.py)"]
Sandbox["Node.js pm.* Script Sandbox<br/>(backend/script_sandbox.js)"]
Store["Local Persistence Layer<br/>(backend/local_db.py)"]
end
subgraph Storage["Zero-Cloud Local Storage"]
JSONFiles["Flat JSON Collections<br/>(data/collections/*.json)"]
SQLiteDB["SQLite Database<br/>(data/openpost.db)"]
end
Agent <-->|"MCP Protocol (stdio/HTTP)"| MCP
UI <-->|"REST API"| API
Desktop <-->|"Localhost / IPC"| API
MCP --> Parser
MCP --> Engine
MCP --> Store
MCP --> Sandbox
API --> Parser
API --> Engine
API --> Store
API --> Sandbox
Parser <--> JSONFiles
Store <--> SQLiteDB
Engine --> Sandbox๐ค Model Context Protocol (MCP) Integration
OpenPost transforms API testing into an entirely agent-operable workflow. Every UI capability is accessible as a structured tool:
Complete MCP Tool Matrix (23 Tools)
Domain | Available MCP Tools |
Collections |
|
Request Authoring |
|
Execution & Runner |
|
Scripting & Sandbox |
|
Environments |
|
History & Audit |
|
REA Autopsy & Sandbox |
|
Connecting to Your AI Client
Add OpenPost to your mcp_config.json (Antigravity, Claude Desktop, Cursor, or Cline):
{
"mcpServers": {
"openpost": {
"command": "python",
"args": ["-m", "backend.mcp_server"],
"cwd": "/path/to/openpost",
"env": {
"PYTHONPATH": "/path/to/openpost;/path/to/openpost/rea_pkg"
}
}
}
}๐งช Pre-Request & Test Scripts (pm.* Sandbox)
OpenPost includes a Node.js-powered execution sandbox supporting authentic Postman scripts:
// Pre-request Script:
pm.environment.set("request_id", "req_" + Date.now());
// Test Script (Chai-Compatible Assertions):
pm.test("Status code is 200", function () {
pm.response.to.have.status(200);
});
pm.test("Response body matches schema", function () {
var json = pm.response.json();
pm.expect(json.status).to.equal("success");
pm.expect(json.data.user.email).to.include("@example.com");
});
// Chaining Tokens into Environment for Downstream Requests:
pm.environment.set("auth_token", pm.response.json().token);When running a collection, environment variables updated by pm.environment.set() automatically persist and chain into all subsequent requests in the run.
๐ฆ Getting Started
1. Installation
Clone the repository and set up the Python environment:
git clone https://github.com/zshortbusz/openpost.git
cd openpost
python -m venv .venv
.\.venv\Scripts\activate
pip install -r requirements.txt2. Launch Options
Option A: WebUI (Browser Mode)
uvicorn backend.main:app --port 8000 --reloadOpen http://127.0.0.1:8000 to access the dark-mode Scratch Pad interface.
Option B: Instant Desktop Launcher
python desktop/run_desktop.py
# Or: npm run desktop:launchSpawns the backend and opens a clean, standalone desktop window in native app mode.
Option C: Tauri Standalone Desktop Build
# Development:
npm run desktop:dev
# Build Windows MSI and EXE Installers:
npm run desktop:buildCompiled installers are output to src-tauri/target/release/bundle/msi/ and nsis/.
๐ก Windows Hosts Sandbox Blocker
To run legacy Postman v9.x or v10.14 without risk of forced auto-updating or cloud sync mandates, use our reversible sandbox blocker:
# In an Administrator PowerShell terminal:
python scripts/block_postman_hosts.py --enable
# Undo / restore hosts file at any time:
python scripts/block_postman_hosts.py --restore
# Check current block status:
python scripts/block_postman_hosts.py --status๐งช Running Automated Tests
OpenPost maintains a strict 100% test-passing invariant across schema ingest, interpolation, MCP tools, and desktop integration:
pytest -v๐ License
OpenPost is released under the MIT License. Postman is a registered trademark of Postman, Inc. OpenPost is an independent clean-room open-source project and is not affiliated with, endorsed by, or associated with Postman, Inc.
This server cannot be deployed
Maintenance
Related MCP Connectors
Give your AI agents trusted access to the full Postman platform.
AI-callable tools for API mocking, testing, monitoring, security, and automation.
- mcp-serverOAuthcom.make
Give your AI agents the tools to build, manage, and run automation workflows.
Discover, inspect and run 63,000+ agent tools from one balance. Pay per call, no subscriptions.
Related MCP Servers
- AlicenseNot gradedqualityDmaintenanceAutomatically converts Postman API collections into MCP-compatible tools for AI assistants. Enables users to interact with any API through natural language by generating JavaScript tools from Postman requests.MIT
- AlicenseNot gradedqualityDmaintenanceEnables interaction with Postman workspaces, collections, requests, responses, and monitors through the Postman API. Allows users to manage API collections, create and update requests/responses, and execute monitors directly from chat.7 npmMIT
- FlicenseNot gradedqualityNot gradedmaintenanceEnables AI agents to dynamically discover and interact with APIs through Swagger/OpenAPI specifications and Postman collections using a strategic four-tool approach. It streamlines API integration by providing universal tools for endpoint discovery, detailed request information, and authenticated execution.1-
- AlicenseCqualityAmaintenanceEnables AI agents to create, manage, and execute API collections, requests, and environments in Insomnia-compatible formats. It supports direct synchronization with the local Insomnia app database and importing from OpenAPI, Postman, and cURL.30682 npm26MIT