An experimental MCP server Rest Client intended to be a replacement of tools postman & insomnia
An experimental MCP server Rest Client intended to be a replacement of tools postman & insomnia. That is what the postmancer mcp server brings to an AI assistant: the same capability, reachable through the Model Context Protocol rather than a separate app or dashboard.
A standalone MCP server for API testing and management, allowing AI assistants to interact with RESTful APIs through natural language.
Postmancer is an MCP (Model Context Protocol) server that enables AI assistants like Claude to make HTTP requests, manage collections of API endpoints, and test API responses. It provides similar functionality to tools like Postman or Insomnia but designed specifically for AI assistants.
Installation goes through your MCP client rather than a global install: point it at npx on npm and it is fetched when the client starts. The copy-paste blocks for Claude Desktop, Claude Code and Cursor are further down this page.
The server publishes 1 tool. What each one is for:
Installation — The Installation tool exposed by this serverConfiguration is passed through the environment: LOG_LEVEL, COLLECTIONS_PATH, POSTMANCER_ENCRYPTION_KEY, ENCRYPTION_KEY. Treat anything key-shaped as a real credential — scope it to the minimum the server needs, and rotate it if it ever lands in a shared config.
Plenty of developer tooling servers cover similar ground. The differences that matter in practice are scope of access and how much setup stands between you and a working tool call. Postmancer's toolset — Installation — is a fair guide to whether it matches your workflow. It is maintained by hijaz; worth a glance at recent repository activity before you build anything load-bearing on it.
SyncDev reviews every entry in this directory against the project's own documentation before publishing, and revisits them as servers change.
| Tool | What it does |
|---|---|
| Installation | The Installation tool exposed by this server. |
{
"mcpServers": {
"postmancer": {
"command": "npx",
"args": ["-y", "npx"],
"env": {
"LOG_LEVEL": "your-value",
"COLLECTIONS_PATH": "your-value",
"POSTMANCER_ENCRYPTION_KEY": "your-value",
"ENCRYPTION_KEY": "your-value"
}
}
}
}Add to claude_desktop_config.json, then restart Claude Desktop.
| Variable | Description | Required |
|---|---|---|
| LOG_LEVEL | Configuration value read at startup. | Optional |
| COLLECTIONS_PATH | Filesystem location the server is allowed to use. | Optional |
| POSTMANCER_ENCRYPTION_KEY | Credential the server authenticates with. | Yes |
| ENCRYPTION_KEY | Credential the server authenticates with. | Yes |
Kill hallucinated APIs — version-accurate, up-to-date library documentation injected straight into context.
Microsoft's official browser automation server — drive a real browser through the accessibility tree, no screenshots needed.
GitHub's official server — repos, issues, pull requests, Actions and code security, straight from your assistant.
Issue tracking at the speed of conversation — Linear's official hosted server with OAuth and zero install.
Local repository surgery — status, diffs, commits, branches and history for any repo on disk.
Timezone sanity for AI — current time anywhere and correct conversions, without the model doing date math.