The server authenticates with a key or token the operator generates and pastes in. Simple to wire, and the key is as powerful as whatever the vendor scoped it to. The bucket is a keyword match over the mcp_auth field, run at build time, and the verbatim field ships in the row beside it so you can check the parse yourself. Where the two disagree, the verbatim field is the fact and the bucket is the convenience.
| Tool | MCP status | Server URL | mcp_auth, verbatim | Gate |
|---|---|---|---|---|
| Autobound autobound.ai | Official MCP | https://www.autobound.ai/integrations/mcp +1 more | api key via an AUTOBOUND_API_KEY environment variable in the MCP client config. | Free to start |
| Browserbase browserbase.com | Official MCP | https://mcp.browserbase.com/mcp +1 more | api key passed as a browserbaseApiKey query parameter on the endpoint URL; the docs list it as "Required for tool calls". Six tools: navigate, act,... | Free to start |
| Buffer buffer.com | Official MCP | https://mcp.buffer.com/mcp +1 more | api key. The vendor's guide instructs the user to generate an API key from the developer site and send it as "Authorization: Bearer YOUR_API_KEY"... | Free to start |
| Census (now operates as "Fivetran Activations") getcensus.com | Official MCP | https://github.com/fivetran/fivetran-mcp | API key + secret via env vars (FIVETRAN_API_KEY, FIVETRAN_API_SECRET). | Free to start |
| Crustdata crustdata.com | Official MCP | https://install.crustdata.com/mcp +2 more | api key (free sandbox key available) | Free to start |
| Diffbot diffbot.com | Official MCP | https://github.com/diffbot/diffbot-mcp | api key (free Diffbot token required to use the MCP tools) | Free to start |
| Enrow enrow.io | Official MCP | https://github.com/EnrowAPI/enrow-mcp +1 more | api key. ENROW_API_KEY env var for stdio, or an Authorization Bearer / x-enrow-api-key header for remote HTTP. | Free to start |
| Exa exa.ai | Official MCP | https://github.com/exa-labs/exa-mcp-server +1 more | api key (issued via dashboard.exa.ai) for the self-hosted server and for quota. CORRECTED 2026-09-03 by bench test: the hosted endpoint... | Free to start |
| Fivetran fivetran.com | Official MCP | https://github.com/fivetran/fivetran-mcp | API key + API secret via env vars, generated from the Fivetran dashboard. Scoped permission tiers (read / read-write / read-write-delete) with a... | Free to start |
| Hunter.io hunter.io | Official MCP | https://hunter.io/api-documentation#mcp | api key (HUNTER_API_KEY) | Free to start |
| Lusha lusha.com | Official MCP | https://github.com/lusha-oss/lusha-public-api-mcp +2 more | api key (LUSHA_API_KEY) | Free to start |
| Model Context Protocol - official servers repo github.com | Official MCP | https://github.com/modelcontextprotocol/servers | Per-server - individual servers take credentials (e.g. API tokens) via environment variables or CLI args where needed; the repo itself has no central... | Free to start |
| n8n n8n.io | Official MCP | https://github.com/n8n-io/n8n +2 more | MCP Server Trigger supports Bearer or Header auth to secure the exposed endpoint; supports SSE and streamable-HTTP transport with separate... | Free to start |
| PredictLeads predictleads.com | Official MCP | https://mcp.predictleads.com/ | api key (same API key/token used for REST API calls, per vendor blog) | Free to start |
| TheirStack theirstack.com | Official MCP | https://api.theirstack.com/mcp/ +3 more | api key (same credentials as the REST API) | Free to start |
| Airspeed (formerly Glyphic) goairspeed.com | Official MCP | https://api.glyphic.ai/mcp +1 more | Airspeed API key passed as an X-API-Key header. | Paid, self-serve |
| Avoma avoma.com | Official MCP | https://mcp.avoma.com/mcp +1 more | API key pair (CLIENT_KEY:CLIENT_SECRET) generated at Settings → Organization → Developer. | Paid, self-serve |
| Bright Data brightdata.com | Official MCP | https://github.com/brightdata/brightdata-mcp | api key (Bright Data API token) | Paid, self-serve |
| Clay clay.com | Official MCP | https://www.clay.com/mcp +1 more | Session cookie - the same token used to log into app.clay.com in-browser, which grants full account access (tables, records, enrichments, CRM... | Paid, self-serve |
| CUFinder cufinder.io | Official MCP | https://mcp.cufinder.io/mcp +1 more | api key from the CUFinder dashboard under Account Settings then API Dashboard. Streamable HTTP transport, explicitly stated by the vendor. | Paid, self-serve |
| Derrick derrick-app.com | Official MCP | https://app1.derrick-app.com/mcp +2 more | api key. The vendor's page states the MCP installs without credentials but every tool call needs a Derrick API key, passed as an Authorization Bearer... | Paid, self-serve |
| Explorium explorium.ai | Official MCP | https://mcp-github-registry.explorium.ai/mcp +3 more | api key | Paid, self-serve |
| Factors.ai factors.ai | Official MCP | https://mcp.factors.ai/mcp +1 more | Personal access token (generated in Settings > AI Features), used via Claude custom connector or a local Python 3.11+ package. | Paid, self-serve |
| HighLevel (GoHighLevel) gohighlevel.com | Official MCP | https://services.leadconnectorhq.com/mcp/ +1 more | A Private Integration Token passed as a bearer token, plus a locationId header. Tool availability follows the scopes granted to the token. | Paid, self-serve |
| Infraforge infraforge.ai | Official MCP | https://mcp.salesforge.ai/mcp | API key, generated from the Infraforge/Salesforge dashboard. | Paid, self-serve |
| Instantly instantly.ai | Official MCP | https://mcp.instantly.ai/mcp +1 more | api key (generated in Instantly Settings > Integrations > API Keys) | Paid, self-serve |
| JustCall justcall.io | Official MCP | https://mcp.justcall.host/mcp +2 more | api key. The vendor's docs show an Authorization header of the form "Bearer <JUSTCALL_API_KEY>:<JUSTCALL_API_SECRET>", a key and secret pair joined... | Paid, self-serve |
| Lead411 lead411.com | Official MCP | https://mcp.lead411.com/mcp +3 more | api key via X-API-KEY header. TRANSPORT IS DISPUTED: the official registry record says SSE, PulseMCP says Streamable HTTP. Verify at connect time. | Paid, self-serve |
| Mailforge mailforge.ai | Official MCP | https://mcp.salesforge.ai/mcp | API key, generated from the Mailforge dashboard. | Paid, self-serve |
| Ocean.io ocean.io | Official MCP | https://app.ocean.io/docs/getting-started/mcp +1 more | api key (api-token passed as a URL parameter to the hosted MCP endpoint) | Paid, self-serve |
| Offorte offorte.com | Official MCP | https://github.com/offorte/offorte-mcp-server +2 more | api key. The repo README lists an "Offorte API Key (see Authentication Section of the Offorte API Docs)"; the server runs locally with npx -y... | Paid, self-serve |
| RB2B rb2b.com | Official MCP | https://registry.npmjs.org/@rb2b/rb2b-apis-mcp | api key | Paid, self-serve |
| Reply.io reply.io | Official MCP | https://reply.io/mcp/ +1 more | api key (personal API key over HTTPS, included in free trial) | Paid, self-serve |
| Salesforge salesforge.ai | Official MCP | https://github.com/SalesforgeAI/forge-mcp | api key via HTTP header (X-Salesforge-Key) | Paid, self-serve |
| Smartlead smartlead.ai | Official MCP | https://helpcenter.smartlead.ai/en/articles/300-smar... +3 more | api key, passed as the user_api_key query parameter on the SSE endpoint URL; SSE transport only (the help article says streamable HTTP is not... | Paid, self-serve |
| Super Send supersend.io | Official MCP | https://mcp.supersend.io/mcp +1 more | api key, Streamable HTTP transport | Paid, self-serve |
| tl;dv tldv.io | Official MCP | https://github.com/tldv-public/tldv-mcp-server +1 more | API key generated at Settings → Personal Settings → API keys. | Paid, self-serve |
| Trainual trainual.com | Official MCP | https://help.trainual.com/en/the-trainual-mcp-server +1 more | Bearer MCP token in the Authorization header; the help article states "Only those with an Admin+ permission level can create MCP tokens" and "The... | Paid, self-serve |
| SigParser sigparser.com | Official MCP | https://ipaas.sigparser.com/api/mcp | unknown. The endpoint answers HTTP 401 to an unauthenticated MCP initialize but no first-party page documents the scheme; SigParser's REST API,... | Enterprise leaning |
| HG Insights (Phoenix platform) hginsights.com | Official MCP | https://learn.microsoft.com/en-us/connectors/hginsig... | api key (`x-api-key` header; throttled to 100 calls/60 seconds per connection) | Enterprise only |
| MadKudu madkudu.com | Official MCP | https://developers.madkudu.com/madkudu-mcp/install-i... +2 more | MadKudu API key embedded in the endpoint path; the portal states "Please contact HG Insights or your account manager if you're interested in the... | Enterprise only |
| Surfe surfe.com | Official MCP | https://mcp.eu.surfe.com/mcp +1 more | Surfe API key, with a browser sign-in flow that exchanges the key for a managed token so it is entered once, or the key passed directly per call.... | Enterprise only |
| GTM Signals andrewcmcguire.com | Official MCP | https://mcp.gtmsignals.co/mcp | api key, sent as `Authorization: Bearer gtms_...`. Streamable HTTP, stateless, protocol version 2025-06-18. The descriptor at... | Gate unknown |
| RevenueHero revenuehero.io | Official MCP | https://www.revenuehero.io/resources/tales-of-ops | Per-customer router token over an SSE endpoint, manually provisioned by RevenueHero - not a self-serve API-key flow. | Gate unknown |
| Loom loom.com | Community MCP | https://github.com/karbassi/mcp-loom +2 more | karbassi/mcp-loom uses Loom's undocumented internal GraphQL API via a browser session cookie (connect.sid) manually extracted from a logged-in... | Free to start |
| People Data Labs peopledatalabs.com | Community MCP | https://github.com/phxdev1/peopledatalabs-mcp | api key (PDL_API_KEY environment variable) | Free to start |
| Mention mention.com | Community MCP | https://github.com/MaelitoP/mention-mcp-server | Mention API key via the MCP_MENTION_API_KEY environment variable | Paid, self-serve |
| Motion usemotion.com | Community MCP | https://github.com/RF-D/motion-mcp | API key (MOTION_API_KEY from Motion Settings -> API), per community repos. Rate limits reported at 12 req/min for individual accounts, 120 req/min... | Paid, self-serve |
| Overloop overloop.com | Community MCP | https://github.com/sortlist/overloop-mcp | api key via OVERLOOP_API_KEY environment variable | Paid, self-serve |
| SavvyCal savvycal.com | Community MCP | https://github.com/arturkoter/savvycal-mcp-server | API key (SAVVYCAL_API_KEY env var, a personal access token from SavvyCal's Developer Settings). MIT-licensed repo, not explicitly disclaiming... | Paid, self-serve |
| Syften syften.com | Community MCP | https://github.com/syntax-syndicate/social-listening | Community server presumably authenticates with a Syften API key (matching Syften's own API auth model); not independently confirmed for this specific... | Paid, self-serve |
| Trigify (Trigify.io) trigify.io | Community MCP | https://github.com/bcharleson/trigify-cli | api key (from app.trigify.io/settings; via `trigify login --api-key`, env var TRIGIFY_API_KEY, or a per-command flag) | Paid, self-serve |
| Chorus zoominfo.com | Community MCP | https://github.com/opensourceops/chorus-mcp-server | Community server: Chorus API key in the CHORUS_API_KEY environment variable (stdio via npx @opensourceops/chorus-mcp), with CHORUS_TOOL_MODE... | Enterprise only |
| Copy.ai (GTM AI Platform) copy.ai | Community MCP | https://github.com/anhuaxiang/copy-ai-mcp | API key via COPY_AI_API_KEY environment variable | Enterprise only |
Counted 2026-09-27 from directory.json and reconciled against tools_recount.py. Nothing on this page is hand maintained: it is a filter over the same 1,252 entries the rest of the site is built from. Ordered by the published rule: official MCP first, then community, then unknown, then n/a, then none-found; within each band gate order is free, paid, enterprise-leaning, enterprise-only, unknown; then alphabetical by name. Computed, never curated, never purchasable.