OnFire MCP Server

The OnFire MCP Server is a bridge between your AI agents and OnFire’s prospecting and contact-enrichment data. It exposes a small set of tools over the Model Context Protocol, so any MCP-compatible client — Claude Desktop, Cursor, ChatGPT, Claude Code, Claude Web — can query and act on OnFire data directly from inside a conversation.

Ready to get started? Jump to the client setup or read on for an overview.

How it works

The OnFire MCP Server is hosted by OnFire. You don’t install or run it yourself — you paste one URL into your MCP client and it takes care of the rest:

• A browser tab opens for you to sign in with your OnFire account.
• Your client remembers the connection.
• The tools become available inside that client’s tool / MCP menu.

Once connected, the agent can run AI prospecting over your CRM data, read prospecting metadata via SQL, and enrich contacts with email and phone data — all scoped to your OnFire tenant.

Ready to get started

The canonical production URL is:

https://mcp.onfire.ai/v1/mcp

Paste it into your MCP client. No headers, no JSON config, no API keys — discovery handles the rest.

Claude Desktop

1. Open Settings → Connectors.

2. Click Add custom connector.

3. Paste https://mcp.onfire.ai/v1/mcp into the URL field and give it a name (e.g. “OnFire”).

4. Click Connect. A browser window opens for you to sign in with your OnFire account.

5. Once signed in, the OnFire tools appear in the connectors panel. You’re done.

Cursor

1. Open Cursor Settings → MCP → Add new MCP server (or edit ~/.cursor/mcp.json).

2. Add an entry of type HTTP with URL https://mcp.onfire.ai/v1/mcp.

3. Save. Cursor reloads the MCP panel, a browser window opens, and you sign in with your OnFire account.

4. The OnFire tools appear in Cursor’s tool list.

Claude Code

Add the remote MCP server from the command line:

claude mcp add --transport http onfire https://mcp.onfire.ai/v1/mcp

The first time you invoke an OnFire tool, a browser window will open for you to sign in with your OnFire account.

ChatGPT

1. Open ChatGPT → Settings → Connectors → Custom connectors.

2. Click New custom connector.

3. Paste https://mcp.onfire.ai/v1/mcp into the URL field.

4. Save. ChatGPT will prompt you to sign in with OnFire the next time you invoke an OnFire tool inside a chat.

Other / custom agent

Any client that implements the MCP spec’s remote-HTTP transport and OAuth 2.1 Dynamic Client Registration can connect. Point the client at:

https://mcp.onfire.ai/v1/mcp

The server publishes standard discovery metadata at /.well-known/oauth-protected-resource and /.well-known/oauth-authorization-server, and a JWKS at /.well-known/jwks.json. A well-behaved MCP client should complete the OAuth handshake automatically on the first request.

Authentication

The OnFire MCP Server uses OAuth 2.1 — exactly the same login flow you already use for every other OnFire product.

When you connect a new client:

1. Your client fetches discovery metadata from the MCP server.
2. It opens a browser window.
3. You sign in with your OnFire account (SSO or password, whichever your organisation uses).
4. Your client stores a short-lived access token plus a refresh token, and transparently refreshes them in the background.

Things to know:

• Your tenant is derived from your email. There’s no tenant picker. Whichever OnFire tenant your email is associated with, that’s the tenant the agent sees.
• No API keys to manage. Access is tied to your OnFire identity. When you leave an organisation, your MCP access is revoked with it.
• Each client is its own registration. Claude Desktop and Cursor each register separately the first time they connect, so revoking access in one does not affect the others.

Fair-use rate limits

The MCP server comes with fair-use limits intended to keep shared downstreams healthy. Current defaults:

• Burst: TBD requests per 10 seconds per user.
• Daily: TBD tool calls per user per day.
• Monthly: TBD tool calls per user per month.

These limits are subject to change. If your use case legitimately requires more, contact support@onfire.ai.

Available tools

The OnFire MCP server exposes a tenant-scoped tool surface — see Tools for the full per-tool reference. The main entry points:

• ai_prospecting — rank likely buyers at a target company, or score one named person.
• manage_ai_prospecting — edit your prospecting schema via the shadow lifecycle.
• match_company and match_person — resolve any starting signal to a verified LinkedIn identity.
• contact_data_enrichment — append verified emails and phones (paid, two-phase consent above 10 contacts).
• search_people and search_companies — composite-filter discovery over the people / company graph.
• bdr_account_research — the canonical BDR brief envelope in one call.
• Datasets — list, describe, query, and download the short-lived CSV datasets that large results land in.

Every tool is tenant-scoped: you only see data belonging to your own tenant. Super-tenant administrators can cross-query other tenants via target_tenant_id, handled transparently by the server.

Context efficiency

Every tool is designed to keep responses small so your agent’s context window doesn’t fill up:

• SQL responses are capped at 1,000 rows, with truncated: true and a total_count when the cap is hit.
• query_datasets is capped at 500 rows inline; persist larger results as a new dataset.
• Large results from search / prospecting / signals / footprint / filings land in a short-lived MCP dataset (CSV in S3, 7-day TTL) — the response carries only a handle plus preview_rows and facets.
• Enrichment is capped at 20 contacts per call; larger jobs are chunked automatically after the consent step.

Monitoring

Every tool call is logged with:

• Your authenticated email (user_email) and tenant (tenant_id).
• The client that made the call — client_id identifies the specific Claude Desktop / Cursor / ChatGPT install that connected.
• Tool name, timestamp, and duration.

OnFire uses these logs to investigate support tickets, detect abuse, and build usage dashboards. Data is subject to the standard OnFire privacy policy.

Troubleshooting

I pasted the URL but nothing happened

The first connection opens a browser window for OAuth login. Some clients pop it behind your IDE or terminal window. Check your browser’s open tabs.

The login loop keeps re-opening

Usually this means your OnFire tenant hasn’t been enabled for MCP access yet. Contact support@onfire.ai with the email address you’re trying to use.

I get “tool not allowed for this tenant”

Your OnFire administrator has scoped the tool surface for your tenant. Two possibilities:

• The tool is intentionally disabled for your tenant. Contact your admin.
• A rollout hasn’t completed yet. Contact support@onfire.ai.

I get a “temporarily unavailable” error

A downstream service the tool depends on is degraded. The server uses circuit breakers so you get a fast, informative error instead of a long timeout. Retry in a minute; if it persists, contact support.

The enrichment call says “confirmation token expired”

The token is only valid for about 5 minutes. Re-run the consent step to get a fresh one, then resume batching.

Feedback & support

The OnFire MCP server is actively developed. If you hit something missing, broken, or confusing, email support@onfire.ai. Include:

• The email you’re authenticated as.
• The MCP client you’re using (Claude Desktop, Cursor, …).
• A minimal reproduction — the prompt you gave, the tool call it triggered, the response you got.
• The timestamp (UTC) when the call was made.