Matrix / Prospecting & Lead Data / Seamless.AI

Seamless.AI MCP server

Prospecting & Lead Data · remote · Up · auth · Docs + endpoint checked 2026-10-16

Seamless.AI has an official hosted MCP server at https://mcp.seamless.ai/mcp. It uses OAuth 2.1 with PKCE (S256), DCR/CIMD; API key in Token header as fallback over Streamable HTTP (stateless JSON-RPC endpoint). Agents can use: Search (contacts, companies, locations), Research/enrich contacts and companies, User (credits, saved contacts/companies). Last checked 2026-10-16 10:06 PT: Up · auth.

Works in: ClaudeChatGPTClaude CodeCursor
Sources: Claude · ChatGPT · Claude Code · Cursor, checked 2026-10-16
Access: Read + write
Credits: Some tools use credits
Plan: Included in existing Seamless plans (MCP access must be enabled on the account; Connect needed for engagement tools)
Setup: Needs admin or IT
An admin or IT has to act first, for example by approving or enabling the integration. Don't plan on connecting it alone. Source: docs.seamless.ai, checked 2026-10-16
Useful for: SDRs, AEs, RevOps, Sales leaders

Seamless.AI MCP endpoint and transport

https://mcp.seamless.ai/mcp

Transport: Streamable HTTP (stateless JSON-RPC endpoint)
Docs: Official Seamless.AI MCP docs

Connect Seamless.AI without code

Seamless.AI's docs confirm it works in Claude and ChatGPT. You don't need a terminal or a config file. Check Seamless.AI's docs first: some vendors give you a personal URL or an API key to use in place of the plain endpoint.

Claude (web and desktop app)

If Seamless.AI shows up when you browse connectors in Claude, connect it from there instead. That skips steps 2 to 4.

In Claude, open Customize → Connectors.
Click + Add, then Add custom connector.
Name it “Seamless.AI”, paste the server URL https://mcp.seamless.ai/mcp, and click Continue.
Review the sign-in settings Claude detected and click Add.
Click Connect and sign in to Seamless.AI. Then ask Claude something like “What can the Seamless.AI connector do?”

On Team and Enterprise plans, an Owner adds the connector first under Organization settings → Connectors → Add → Custom → Web. Each person then connects it from Customize → Connectors. Free plans can add one custom connector.

Steps from the Claude Help Center: support.claude.com, checked 2026-10-16

ChatGPT

If Seamless.AI has its own plugin in ChatGPT's directory, install that instead.

Go to chatgpt.com/plugins.
Select +, then Add custom MCP server. If you don't see it, your plan or workspace settings may not allow custom servers, so ask your workspace admin.
Enter a name and description. Under Connection, paste the server URL https://mcp.seamless.ai/mcp.
Set up sign-in, read the warning, and select I understand and want to continue.
Select Create as a plugin. In a new chat, type @ and pick Seamless.AI.

Steps from the OpenAI developer docs: developers.openai.com, checked 2026-10-16

From Seamless.AI's docs: Listed in the Claude connector directory and ChatGPT plugin directory. ChatGPT custom MCP supported on Pro, Plus, Business, Enterprise or Education accounts. MCP access must be enabled on the Seamless account; campaign, email, call, task and activity tools require Connect access.Source: docs.seamless.ai, checked 2026-10-16

Developer setup (Claude Code, Cursor)

Add this to .mcp.json (Claude Code, project root) or ~/.cursor/mcp.json (Cursor). Remove the // comment line if your client requires strict JSON.

{
  "mcpServers": {
    "seamless.ai": {
      "url": "https://mcp.seamless.ai/mcp"
    }
  }
}

Add the endpoint to your client config (above), or as a custom connector in Claude.
Complete the OAuth sign-in. In Claude Code, run /mcp and pick the server.
Test it with a prompt like: “List the tools the Seamless.AI MCP server exposes.”

Seamless.AI MCP authentication

OAuth 2.1 with PKCE (S256), DCR/CIMD; API key in Token header as fallback

Sign in with OAuth in your client (run /mcp in Claude Code). Do it once interactively, and the client stores and refreshes the token.

What it can change

Read + write Some Seamless.AI MCP tools change data, not just read it.

Things it can do in your Seamless.AI account:

enriches (researches) contacts and companies
sends email and bulk email
creates and edits email drafts and templates
creates, updates, launches and deletes campaigns and adds contacts to them
logs calls
creates, updates and deletes tasks
creates, updates and deletes lists and saved searches

Source: docs.seamless.ai, checked 2026-10-16

Review each change before you approve it, especially anything that sends messages or edits records other people rely on.

Cost and credits

Some tools use credits

Search is free; research/enrich tools (research_contacts, research_companies) consume credits, and re-enriching with skipDeduplicationCheck consumes credits again. send_bulk_email does not consume credits.

Source: docs.seamless.ai, checked 2026-10-16

Plan required

Included in existing Seamless plans (MCP access must be enabled on the account; Connect needed for engagement tools)

Source: seamless.ai, checked 2026-10-16

Admin and governance

Controls Seamless.AI itself provides. Settings inside Claude or ChatGPT aren't counted here.

An admin must approve or enable the connectionYesSource: docs.seamless.ai, checked 2026-10-16
Scopes or permissions can limit what it reachesNot confirmed
Individual tools can be turned offNot confirmed
MCP activity shows in an audit logNot confirmed

What the Seamless.AI MCP server can do

Search (contacts, companies, locations)
Research/enrich contacts and companies
User (credits, saved contacts/companies)
Lists
Saved searches
Campaigns (Connect)
Templates (Connect)
Email drafts, send, bulk send (Connect)
Calls (Connect)
Tasks (Connect)
Activity feed (Connect)

Seamless.AI MCP status

Up · auth HTTP 401 · 363 ms · checked 2026-10-16 10:06 PT. Full status and history.

Seamless.AI MCP FAQ

What is the Seamless.AI MCP server URL?

https://mcp.seamless.ai/mcp

How does Seamless.AI MCP authenticate?

OAuth 2.1 with PKCE (S256), DCR/CIMD; API key in Token header as fallback.

Which apps does Seamless.AI MCP work with?

Seamless.AI's docs confirm it works in Claude, ChatGPT, Claude Code and Cursor. Other apps aren't confirmed in the docs yet.

Can I connect Seamless.AI MCP on my own?

Not always. The vendor's setup notes say an admin or IT has to act first, for example by approving or enabling the integration. See the setup notes on this page.

Can I use Seamless.AI in Claude or ChatGPT without code?

Yes. Seamless.AI's docs confirm it works in Claude and ChatGPT. Add it as a connector in the app settings and sign in. No terminal or config file needed.

Can the Seamless.AI MCP server change my data?

Yes. Some tools change data, for example: enriches (researches) contacts and companies, sends email and bulk email, creates and edits email drafts and templates. Review each change before you approve it.

Does Seamless.AI MCP use credits?

Some tools use credits. Search is free; research/enrich tools (research_contacts, research_companies) consume credits, and re-enriching with skipDeduplicationCheck consumes credits again. send_bulk_email does not consume credits.

What Seamless.AI plan do I need for MCP?

Included in existing Seamless plans (MCP access must be enabled on the account; Connect needed for engagement tools).

Is the Seamless.AI MCP server official?

Yes. It's documented on docs.seamless.ai, last checked 2026-10-16.

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