Developers & AI

API and MCP access

Everything the filing wizard does is available programmatically: look up a company, check it fits, compute the tax position live, save draft filings and generate the document pack. An AI assistant can prepare a return for you to review; only a human director reviews and submits it in the web product, at file.axel.trade.

Connect your AI (free)

No account or key needed to start. The MCP server lives at one URL:

https://portal.axel.trade/api/mcp

Point any MCP-aware assistant at it and sign in when prompted; the authorization happens in your browser, no key to copy or paste.

claude.ai

Settings → Connectors → Add custom connector → paste the URL above. Claude will open a sign-in tab, you approve access, and the assistant is connected.

ChatGPT

Enable developer mode connectors, then add a connector with the same URL. Approve the sign-in prompt the same way.

Claude Code

One command; OAuth runs automatically in the browser the first time a tool is used.

claude mcp add axel-filing https://portal.axel.trade/api/mcp

Claude Desktop

Claude Desktop speaks stdio, not HTTP, so bridge with mcp-remote. No key in the config: the first tool call opens a browser tab for sign-in and consent.

{
  "mcpServers": {
    "axel-filing": {
      "command": "npx",
      "args": ["mcp-remote", "https://portal.axel.trade/api/mcp"]
    }
  }
}

Developer API (£49 per month)

For your own code, or an AI client that needs a long-lived key instead of an interactive OAuth login. Create keys under My account → API access and send them as a bearer token. Keys unlock both the REST API and the MCP server, plus a discounted filing rate while the plan is active. Note the OAuth connect flow above stays free but does not carry the discounted rate; that applies only to filings prepared via an API key.

Authorization: Bearer axk_...

Launching shortly. Keys and the developer rate switch on the moment the plan is live. The OAuth connect flow above is available now and stays free.

Pricing while subscribed

£49 per month, cancel any time from the account page.

Full API reference

The endpoint reference, request and response shapes, the MCP tool list and worked curl examples live inside your account, at file.axel.trade/api-docs. Signing up is free and takes a moment; you do not need a Developer plan to read it.

The machine-readable description stays open, so an assistant can discover the API without an account:

https://portal.axel.trade/api/v1/ct600/openapi.json

Submission

Transmission to HMRC is not exposed over the API yet; we are completing HMRC's recognition testing. Drafts created here appear in your account at file.axel.trade and are submitted from there once filing opens. Rate limits are generous for real use; be reasonable.

Figures submitted through the API remain the account holder's responsibility.