Apollo.io: MCP server, CLI and agent surfaces
Sign-in required, tools not seen, not counted. The MCP endpoint listed for Apollo.io at mcp.apollo.io answered 401 with OAuth metadata on 4 November 2026. Its tools can be listed only after a person authorizes a client, and this directory never signs in.
Fact sheet
| Company | Apollo.io |
|---|---|
| Domain | apollo.io |
| Category | CRM (Ora leaderboard category) |
| MCP server | Sign-in required (OAuth with client registration) |
| Tranco rank | 7,431 on the list of 4 November 2026 |
| Ora score | 76, grade B; Ora scanned the domain on 3 November 2026 and the cached score was read on 5 November 2026 from its score API (Ora's score page for apollo.io, a vendor-published score) |
| Company found through | the GitHub MCP Registry; Ora's public leaderboard |
| Last verified | 4 November 2026 |
MCP server
| Endpoint | https://mcp.apollo.io/mcp |
|---|---|
| How it was found | listed in the GitHub MCP Registry; Ora's public leaderboard |
| Transport | streamable-http |
| HTTP status | 401 |
| Connected | 4 November 2026, 20:01 UTC |
| Handshake time | 1,091 ms over 1 attempt |
The endpoint answered the handshake with a sign-in challenge, so the tool list is not visible to this directory. It is not counted as an MCP server: a sign-in challenge is its own state, and the connector listed no tools.
Connector log
2 connections on 4 November 2026, read-only methods only
- 19:56:12Z https://mcp.apollo.io/mcp sent initialize result auth-required (HTTP 401) 717 ms
- 20:01:51Z https://mcp.apollo.io/mcp sent initialize result auth-required (HTTP 401) 1091 ms
Authentication
| Auth type | OAuth with client registration |
|---|---|
| What the challenge said | Bearer realm="Apollo.io", resource_metadata="https://mcp.apollo.io/.well-known/oauth-protected-resource", scope="read_user_profile app_scopes people_bulk_match organizations_bulk_enrich organizations_enrich people_match webhook_result_read mixed_people_api_search organizations_job_posting mixed_companies_search organizations_search contact_write contact_update contacts_search contact_read contacts_deduplicate account_write account_update context_center_read context_center_write emailer_campaigns_search emailer_campaigns_create emailer_campaigns_update emailer_campaigns_approve emailer_campaigns_add_contact_ids emailer_campaigns_remove_or_stop_contact_ids emailer_schedules_list emailer_messages_search emailer_messages_create emailer_messages_send_now emailer_messages_email_send_status emailer_messages_get_content emailer_campaigns_activity_feed report_sync agent_task email_accounts_list |
| Protected resource metadata | mcp.apollo.io |
| Authorization server metadata | mcp.apollo.io |
| Registration endpoint | https://mcp.apollo.io/api/v1/oauth/applications/register_oauth_client |
| Client ID metadata documents | supported |
The sign-in route, step by step
- Request
https://mcp.apollo.io/mcpwithout a token. It answers 401 and aWWW-Authenticateheader. - Read the protected resource metadata at
https://mcp.apollo.io/.well-known/oauth-protected-resourceto find the authorization server. - Register a client at the registration endpoint
https://mcp.apollo.io/api/v1/oauth/applications/register_oauth_client(dynamic client registration), so no human has to create an app first. - Send a person through the authorization page, then retry the endpoint with the bearer token. The connector stops after step 2 and never authorizes.
See OAuth for MCP: client ID metadata documents and dynamic registration for how each route works.
CLI
No CLI is on record for Apollo.io. The directory checks a package only where a source names one, so this is a floor: a company can ship a command line that no source read for this edition mentions. See shipping a CLI agents can use.
Other agent surfaces
| Surface | Result |
|---|---|
| OpenAPI file | Not read: the site's robots.txt disallows the path for this crawler. |
| WebMCP in the initial HTML | Not detected on the home page by the shared crawl. |
| MCP discovery file | Not found (the crawl got a non-200 answer). |
| A2A agent card | Not found (the crawl got a non-200 answer). |
| A2A agent card (older path) | Not found (the crawl got a non-200 answer). |
| agents.json | Not found (the crawl got a non-200 answer). |
| OAuth authorization server metadata | Not found (the crawl got a non-200 answer). |
| NLWeb endpoint | Not checked in this edition. |
Registry listings
| Registry | Listed |
|---|---|
| Official MCP Registry | No |
| GitHub MCP Registry | Yes |
| awesome-remote-mcp-servers | No |
| Smithery | Not checked: Smithery's listing pages and search API were unavailable on 4 November 2026. |
| Glama | Not checked: Glama's API needs a key and attribution terms. |