MCP authentication: API keys and OAuth

Choose the connection you need

Public discovery at https://toolcargo.com/mcp searches server listings and returns setup details without authentication. It does not execute the servers you find. To use a ToolCargo hosted connector, copy its own server URL and connect with a scoped ToolCargo API key or OAuth. A provider connection, such as Google authorization for Search Console, is a separate requirement listed on that connector's page.

Follow client setup and tested support status for the method your client offers. For 401, 403 or missing tools, use the connection troubleshooting guide.

API keys

• Created in the dashboard; shown once. We store only a SHA-256 hash, so a lost key cannot be recovered — revoke it and create another.
• Format: tp_live_ followed by 43 random characters. Send as Authorization: Bearer …. Keys in URLs or query strings are not accepted.
• Each key carries scopes, one per connector (for example connector:site-audit). A key without a connector's scope gets HTTP 403 on that connector.
• Up to 10 active keys per account. Keys do not expire; revocation takes effect on the next request.

OAuth

Use the client's OAuth connection flow when available. Client features and plan requirements differ; check the setup guide above. ToolCargo runs an OAuth 2.1 authorization server:

• Authentication discovery: hosted connector endpoints answer unauthenticated requests with HTTP 401 and a WWW-Authenticate header pointing to their Protected Resource Metadata (RFC 9728), e.g. https://toolcargo.com/.well-known/oauth-protected-resource/mcp/site-audit. Server metadata is at https://toolcargo.com/.well-known/oauth-authorization-server. The public directory endpoint has no authentication requirement.
• Clients identify with a Client ID Metadata Document (an https URL) or register dynamically (RFC 7591). Public clients only.
• Authorization code flow with PKCE (S256 required). The resource parameter binds tokens to one connector, e.g. https://toolcargo.com/mcp/site-audit; a token for one connector is rejected by another.
• Access tokens last one hour. Refresh tokens last 30 days and rotate on every use; reusing an old refresh token or authorization code revokes the whole grant.
• Every approval appears under “Connected apps” in your dashboard, where you can revoke it.

Rate limits and quotas

• Per credential: calls per minute depend on the plan (see pricing).
• Included hosted connectors share the Site Audit plan's monthly allowance; separate connector scopes do not create separate allowances. Calls are reserved atomically and refunded for invalid input, unreachable targets or failures on our side.
• Successful metered tool results include the current monthly usage. A returned Site Audit report for a blocked or error page still counts; a failed fetch does not. See the usage policy for multi-page calls and other details.

Account isolation

Every credential resolves to exactly one account. Tools run with that account's entitlement and record usage against it; dashboard actions (revoking keys, cancelling, deleting) only affect rows owned by the signed-in account. When audit history is enabled, Site Audit saves reports to that account's history, including URLs, findings and short page evidence. You can switch history off or delete saved reports; retention is 180 days. Fetched page HTML is not stored. See the privacy policy for storage and retention details.

Keep ToolCargo keys out of repository commits, URLs and support messages. If a key is exposed, revoke it in the dashboard and create a replacement with only the connector scopes you need.