techwriter-mcp

Write repository documents from verified codebase facts. Your coding agent investigates the repository, this server sends those facts to a separate model that writes the document, and the agent fact-checks the result before sending corrections back.

Install with Claude Code

/plugin marketplace add paraspace-dev/techwriter-mcp
/plugin install techwriter-mcp@techwriter-mcp

Claude Code prompts once for an OpenAI API key and stores it in the OS keychain. The plugin registers the techwriter MCP server, a skill that keeps the agent in the facts-in role, and a command to set up project writing configuration:

/techwriter-mcp:techwriter-init

How it works

The agent calls create for a new document, then checks the result against the repository. If it finds an error, it calls edit with the corrected facts rather than rewriting the prose itself.

Use review when you want editorial findings instead of a rewrite. It returns findings with locations, or reports that the document has no significant editorial problems.

The fact-check matters. Wrong facts produce a well-written wrong document.

techwriter-mcp writes plans, RFCs, design and architecture docs, READMEs, guides, explanations, ADRs, pull request descriptions, and issues. For PRs and issues, the first line of the document is the title as a # heading; the agent strips it and passes it to gh separately.

Other MCP hosts

The server is the npm package techwriter-mcp. Run it as npx -y techwriter-mcp@latest with OPENAI_API_KEY in its environment.

Claude Code project configuration

For Claude Code without the plugin, add the server to .mcp.json:

{
  "mcpServers": {
    "techwriter": {
      "command": "npx",
      "args": ["-y", "techwriter-mcp@latest"]
    }
  }
}

Codex

For Codex, add the server to ~/.codex/config.toml:

[mcp_servers.techwriter]
command = "npx"
args = ["-y", "techwriter-mcp@latest"]

Give it your project's voice

Configuration is optional. Without .techwriter-mcp/, the server uses its editorial brief and a default model.

Add examples and writing rules when you want the document to sound like your project:

.techwriter-mcp/
  config.toml       model choice, voice corpus globs
  instructions.md   your house style, in your words
  voice/
    examples/       documents that sound the way you want
    avoid/          counterexamples of the style you keep deleting

[model]
model = "gpt-5.6-terra"

[voice]
include = ["docs/**/*.md", "README.md"]
exclude = ["docs/generated/**"]

Files in voice/ and files matched by include become the voice corpus. A few strong examples usually teach the model more than a long instructions file.

If your existing documentation is AI-written, adding it to include teaches the model that same voice. Pre-AI READMEs and posts make better examples. AI originals recovered from git history can go in voice/avoid/.

The corpus is capped at max_kb, which defaults to 256 KB. The server reports files it drops for the budget. The corpus is sent with every request and uses the provider's prompt cache, so it is nearly free after the first call of a session. Set TECHWRITER_MCP_DEBUG=1 to print input, cached, and output token counts to stderr.