@stratta/mcp

MCP server exposing Swiss engineering norms (SIA / Eurocodes) to Claude clients via Stratta TreeRAG.

Requires a free Stratta account. Sign up at https://stratta.ch and generate an API key at https://stratta.ch/api-keys.

[!IMPORTANT] Your STRATTA_API_KEY is a secret — it grants read/write access to your Stratta workspace. Never commit it to a repository, paste it into a shared/ project-scoped MCP config, or share it in logs. Prefer a user-scoped config or a shell environment variable. If a key leaks, revoke it immediately at https://stratta.ch/api-keys.

Install

Claude Code (recommended)

Add the server — no key needed up front:

claude mcp add stratta -- npx -y @stratta/mcp

On the first call, Claude Code prompts you to paste your Stratta API key. It's validated and saved to ~/.stratta/config.json (owner-only, 0600), so you only do this once.

Prefer to set it up ahead of time? Log in via the CLI:

npx -y @stratta/mcp login

…or pass the key explicitly as an environment variable (it then takes precedence over the saved key):

claude mcp add stratta --scope user --env STRATTA_API_KEY=sk_strt_xxx -- npx -y @stratta/mcp

Claude Desktop

Save your key once via the CLI:

npx -y @stratta/mcp login

Then add the server to claude_desktop_config.json (Settings → Developer → Edit Config) — no key needed in the file:

{
  "mcpServers": {
    "stratta": {
      "command": "npx",
      "args": ["-y", "@stratta/mcp"]
    }
  }
}

Restart Claude Desktop. The Stratta tools should appear in the MCP indicator.

Prefer to keep the key in the config instead of ~/.stratta/config.json? Add an "env": { "STRATTA_API_KEY": "sk_strt_xxx" } block to the server entry — but that file then stores the key in plaintext, so keep it private and unsynced.

Global install (optional)

npm install -g @stratta/mcp

Then use "command": "stratta-mcp" instead of npx.

Configuration

The API key is resolved in this order: the STRATTA_API_KEY env var, then ~/.stratta/config.json (written by login or the first-run prompt). Other settings come from environment variables — see .env.example.

| Variable | Required | Default | Purpose | |---|---|---|---| | STRATTA_API_KEY | no¹ | – | API key from https://stratta.ch. ¹If unset, the server falls back to ~/.stratta/config.json, or prompts you on first use (clients that support elicitation). | | STRATTA_CONVEX_URL | no | Stratta prod backend | Override only if you self-host. |

Tools exposed

| Tool | Purpose | |---|---| | list_norms | List all available norms (code, year, title, language). | | get_toc | Get the hierarchical table of contents for a norm. | | get_section | Fetch the full enriched content of a section (with formulas, tables, cross-refs). | | search_in_norm | Search sections within a norm by keyword. | | get_figure | Retrieve a figure (image) inline (base64) to reason about diagrams. | | get_cross_refs | List outgoing cross-references from a section to other norms. |

How agents should use it

1. Call list_norms to see what's available.
2. Call get_toc(norm) to navigate the structure.
3. Call get_section(norm, path) to read specific content.
4. Use search_in_norm when the section path is unknown.
5. Follow crossRefs for compound questions (e.g. SIA 261 → SIA 263 → EC).
6. Call get_figure when the section references a figure relevant to the answer.

Troubleshooting

Authentication failed / Invalid API key

• Verify the key starts with sk_strt_ and is not revoked at https://stratta.ch/api-keys.
• Check the env var is reaching the process: echo $STRATTA_API_KEY (or $env:STRATTA_API_KEY on Windows PowerShell).
• If you copied from the UI, make sure no leading/trailing whitespace was added.

ECONNREFUSED / network errors

• Confirm outbound HTTPS to *.convex.cloud is allowed by your firewall/VPN.
• Try curl -I https://stratta.ch to verify general internet reachability.

Tools don't appear in Claude

• Restart your Claude client after editing the config.
• Check the MCP server logs (Claude Code: claude mcp logs stratta; Claude Desktop: ~/Library/Logs/Claude/mcp-server-stratta.log on macOS).
• Make sure your Node.js version is >=20 (node --version).

Rate-limited

• Each user can create up to 50 active keys and 20 new keys per 24h. Revoke unused keys in the dashboard.

License

Proprietary — © SmartFlow (Hugo Gebel). All rights reserved. This package is the official Stratta MCP client; redistribution, modification, or reuse of the source is not permitted without prior written consent.