Magellan Data MCP

Corporate ownership intelligence for AI agents. Connect Claude, Cursor, or any MCP-compatible client to Magellan Data's Spotlight platform and ask who owns whom — parent companies, PE backing, corporate families, and portfolio siblings — over lists of thousands of companies at a time.

Hosted server. No install. Bring your own API key.

https://spotlight-mcp.magellandata.io/mcp

That's an MCP endpoint, not a web page — paste it into your client's config, not your browser. Opening it directly returns an error, which is the correct behaviour for every hosted MCP server.

Try asking

Once connected, these all work in plain language:

"Read accounts.xlsx and tell me which of these companies are PE-backed, and by whom."

"We just closed Moosend. Find every other company owned by the same PE firm — those are our warm expansion targets."

"Which of my 200 accounts are subsidiaries of a larger parent? Append the parent company to the spreadsheet and save it."

"Map the full corporate family under Constant Contact's parent so I can see the sister companies I'm not covering."

The agent handles the whole pipeline — submitting the batch, polling until the runs finish, checking the price, and joining results back to your original file by input_url.

Related MCP server: companylens-mcp

Quick start

1. Get an API key. Sign up at magellandata.io and generate a key from the Spotlight dashboard. Keys look like mgln_sk_live_…. Every key carries its own credit balance, and usage is billed to the key that made the call.

2. Connect your client.

claude mcp add --transport http magellan-data https://spotlight-mcp.magellandata.io/mcp \
  --header "Authorization: Bearer mgln_sk_live_YOUR_KEY"

claude mcp list   # expect: magellan-data ... ✓ Connected

Add to ~/.cursor/mcp.json (or .cursor/mcp.json in a project):

{
  "mcpServers": {
    "magellan-data": {
      "url": "https://spotlight-mcp.magellandata.io/mcp",
      "headers": {
        "Authorization": "Bearer mgln_sk_live_YOUR_KEY"
      }
    }
  }
}

Add to .vscode/mcp.json — this prompts for the key rather than storing it in the file:

{
  "inputs": [
    {
      "type": "promptString",
      "id": "magellanKey",
      "description": "Magellan Data API key (mgln_sk_live_...)",
      "password": true
    }
  ],
  "servers": {
    "magellan-data": {
      "type": "http",
      "url": "https://spotlight-mcp.magellandata.io/mcp",
      "headers": { "Authorization": "Bearer ${input:magellanKey}" }
    }
  }
}

The server speaks Streamable HTTP and is stateless. Point any compliant client at https://spotlight-mcp.magellandata.io/mcp with an Authorization: Bearer <key> header.

3. Verify. Ask your agent: "Check my Magellan Data credit balance." If it comes back with a number, you're connected. That call is free.

What you can look up

parent_companies and pe_ownership are flat-rate, so the agent can quote you an exact cost before spending anything. The other two are priced per output record — the price isn't known until the run completes, so the agent reads it off the run and tells you before downloading.

How credits work

This is the part worth understanding, because it's what keeps an autonomous agent from quietly burning your balance:

• Submitting a batch is free. So is starting the processing runs, polling their status, and checking your balance.

• Credits are charged at exactly one point: download_run. Nothing before it costs anything.

• The agent surfaces the price first. Every run carries a price field, and the server instructs connected clients to state that number and wait for you before downloading.

• Re-downloads are free, forever. Once a run is purchased it stays purchased. If a download link expires, just ask again — no second charge.

If you'd rather not think about it: everything up to and including "how much will this cost" is free, and the agent will ask.

Tools

The flow is always submit → process → poll → download. Results come back as a presigned S3 link (1-hour TTL) rather than inline, so a 2-million-row result set never touches your agent's context window. The link needs no auth header — hand it straight to curl, pandas.read_csv, or a browser.

There's also a magellan_playbook prompt — a GTM strategy guide covering expansion- target ranking, deal_type interpretation, and MSA-timing triggers. In Claude Code it shows up as a slash command under the magellan-data server.

Working example

examples/quickstart.py runs the full pipeline against the REST API directly — useful for understanding what the agent is doing under the hood, or for wiring Magellan Data into a non-agentic pipeline.

export MAGELLAN_API_KEY=mgln_sk_live_YOUR_KEY
python examples/quickstart.py --urls moosend.com constantcontact.com --type pe_ownership

examples/accounts.csv and accounts.xlsx are a 12-row fixture you can point an agent at without supplying your own data. The companies span independents, acquired subsidiaries, and PE-backed businesses, so each output type returns something. Enriching all twelve costs 840 credits per flat-rate output type — cheap enough to validate the pipeline for real.

It stops and asks before the download step, so you can run it end to end without spending credits until you mean to.

examples/PROMPTS.md has a walkthrough of agent prompts in increasing order of ambition, with the expected cost of each noted up front.

Skills

The skills/ directory holds task-focused playbooks that turn raw tool output into a finished deliverable — a ranked target list, a coverage map, an enriched spreadsheet — instead of JSON. Clients that support skills can load them from this repo; clients that don't can still be pointed at the markdown directly.

Repository contents

.mcp.json                     MCP registration (Claude Code, Codex)
mcp.json                      MCP registration (Cursor)
.vscode/mcp.json              MCP registration (VS Code, prompts for key)
.claude-plugin/
  plugin.json                 Claude plugin metadata
  marketplace.json            Claude marketplace metadata
server.json                   Official MCP Registry metadata
skills/*/SKILL.md             Task playbooks
examples/
  quickstart.py               Full pipeline against the REST API
  PROMPTS.md                  Agent prompt walkthrough
  accounts.csv         12-row test fixture
  accounts.xlsx        Same fixture, spreadsheet form
assets/
  logo.png                    Wordmark, navy (for light backgrounds)
  logo-light.png              Wordmark, white (for dark backgrounds)
  social-preview.png          1280x640 social card — upload under
                              Settings > Social preview
  social-preview-light.png    Light-background alternate

To use the manifests locally:

git clone https://github.com/sorrek/mcp.git

Then point your client at the repo root or the specific manifest path.

Troubleshooting

The endpoint URL shows an error in my browser. Expected. /mcp speaks JSON-RPC over POST; the transport spec reserves GET on that path for opening an event stream, so a server like this one that doesn't offer streams answers with 405. There's nothing to see there. To check the server is actually up, ask your agent to call check_credits — that's free and exercises the whole auth path.

My client connects but lists no tools. Almost always an auth problem rather than a transport one. Confirm the header is Authorization: Bearer mgln_sk_live_... with the Bearer prefix, and that the key is active in the Spotlight dashboard.

A download link returns 403 with Request has expired. Presigned URLs last an hour. Call download_run again for a fresh one — re-downloads are free.

A run has been processing for a long time. Large batches take minutes, not seconds. Poll every 10–30 seconds rather than in a tight loop. If a run sits past 20 minutes, open an issue with the run_id.

Notes and limits

• Batch size: up to 5,000 URLs per batch. Larger lists should be chunked; the agent will do this if you ask.

• Timing: large runs take minutes, not seconds. Polling every 10–30 seconds is the right cadence and the server instructions say so.

• Overlapping inputs: if two input companies share a parent or a PE firm, you're charged for both inputs. Every output row carries input_url, so deduplicating client-side is trivial.

• Auth: API key per request, passed through to the Spotlight API so usage is attributed to the right user. OAuth is planned; see below.

Roadmap

• OAuth 2.1 for one-click connection from claude.ai and ChatGPT, without hand-pasting keys

• Listing in the official MCP Registry and downstream directories

• last_verified timestamps on ownership records

Issues and feature requests are welcome — open one on this repo.

Support

• API documentation: docs.magellandata.io

• Bugs and requests: open an issue

• Data quality problems: support@magellandata.io

• Commercial questions: magellandata.io

License

MIT — this repository. The Spotlight API itself is a commercial service governed by the Magellan Data terms of service.