Using POP from an AI assistant with no install (remote MCP)

Integrationsmcp-ai2026-07-24

Goal

Connect an AI assistant (Claude, or any MCP-speaking client) to POP’s official remote MCP server (https://mcp.popapi.io/mcp), without installing Node.js or configuring anything locally — unlike the local version, all you need here is a URL.

Prerequisites

A valid POP license_key (see get-your-license-key) — or, if you don’t have an account yet, you can create one by talking to the assistant itself: see onboard-via-ai-assistant.
A client that supports MCP over HTTP: Claude (remote connector), OpenAI Responses API, n8n, MCP Inspector, or a custom integration.

How it works

Endpoint: https://mcp.popapi.io/mcp — Streamable HTTP transport.
The server is stateless and multi-tenant: there’s no license_key configured server-side like in the local version. Every single request must carry your key as a header:
```
Authorization: Bearer your_license_key
```
If the header is missing or malformed, the request fails with 401 (unauthorized_user) before calling the POP API. If the key is present but invalid, the request reaches POP and returns whatever error POP itself generates (e.g. unauthorized_user, insufficient_level).

Connecting Claude

Add a new remote connector pointed at https://mcp.popapi.io/mcp, with header Authorization: Bearer your_license_key — the exact steps depend on which version of Claude you’re using (desktop or web): look for “connector” or “remote MCP” in settings.

Trying it with MCP Inspector

npx @modelcontextprotocol/inspector

Point it at https://mcp.popapi.io/mcp, with the same Authorization: Bearer header.

Trying it with curl

curl -X POST https://mcp.popapi.io/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -H "Authorization: Bearer your_license_key" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'

Available tools (16)

The same 11 tools from the local version (SdI/PEPPOL/KSeF/ZUGFeRD/PDF creation, Zoho sync, status, verification, preservation), plus 5 onboarding tools (pop_onboarding_request_otp, pop_onboarding_verify_otp, pop_onboarding_get_status, pop_onboarding_get_account_setup, pop_onboarding_save_account_setup) that don’t require the Bearer header: they use their own temporary onboarding_token, designed specifically for creating a brand-new account. See onboard-via-ai-assistant for the full flow.

Good to know

The server runs as a serverless function: it’s stateless, every request is independent — don’t expect it to remember earlier conversations beyond whatever the MCP client itself manages.
https://mcp.popapi.io/health is a status endpoint meant for monitoring, not for conversational use.

Common errors

Immediate 401 unauthorized_user — the Authorization header is missing or not in the Bearer <key> format: the server rejects it before even contacting POP.
Key present but request rejected by POP — the key is formally valid but POP rejects it (insufficient plan, integration not active): the returned error is POP’s, not the MCP server’s.
Client can’t find the right tool — check that you connected the client to the /mcp URL (not the https://mcp.popapi.io/ home page, which is just the informational landing page).

For the local install (stdio, via npm) see mcp. For the full invoice data contract, see api/overview, api/sdi, api/peppol, api/ksef, api/zugferd, api/pdf, and api/zoho.