Create Tunnel Certificate

POST /v1/tunnels/\{tunnel_id\}/certificates

The Tunnels API is in research preview. It requires the anthropic-beta: mcp-tunnels-2026-06-22 header and may change without a deprecation period. It supersedes the Admin API endpoints at /v1/organizations/tunnels, which remain available during a migration window.

Registers a public CA certificate on a tunnel. Anthropic verifies the gateway's server certificate against this CA when it terminates the inner TLS session. A tunnel holds at most two non-archived certificates.

Path parameters

• tunnel_id: string

Headers

• "anthropic-beta": optional array of AnthropicBeta

  Optional header to specify the beta version(s) you want to use.

  • string

  • "message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 42 more

    • "message-batches-2024-09-24"

    • "prompt-caching-2024-07-31"

    • "computer-use-2024-10-22"

    • "computer-use-2025-01-24"

    • "pdfs-2024-09-25"

    • "token-counting-2024-11-01"

    • "token-efficient-tools-2025-02-19"

    • "output-128k-2025-02-19"

    • "files-api-2025-04-14"

    • "mcp-client-2025-04-04"

    • "mcp-client-2025-11-20"

    • "dev-full-thinking-2025-05-14"

    • "interleaved-thinking-2025-05-14"

    • "code-execution-2025-05-22"

    • "extended-cache-ttl-2025-04-11"

    • "context-1m-2025-08-07"

    • "context-management-2025-06-27"

    • "model-context-window-exceeded-2025-08-26"

    • "skills-2025-10-02"

    • "fast-mode-2026-02-01"

    • "output-300k-2026-03-24"

    • "user-profiles-2026-03-24"

    • "user-profiles-2026-08-18"

    • "user-profiles-2026-09-04"

    • "advisor-tool-2026-03-01"

    • "managed-agents-2026-04-01"

    • "cache-diagnosis-2026-04-07"

    • "dreaming-2026-04-21"

    • "thinking-token-count-2026-05-13"

    • "server-side-fallback-2026-06-01"

    • "server-side-fallback-2026-07-01"

    • "fallback-credit-2026-06-01"

    • "fallback-credit-2026-07-01"

    • "agent-memory-2026-07-22"

    • "mid-conversation-tool-changes-2026-07-01"

    • "compact-2026-01-12"

    • "computer-use-2025-11-24"

    • "mcp-tunnels-2026-06-22"

    • "structured-outputs-2025-11-13"

    • "task-budgets-2026-03-13"

    • "thinking-display-updates-2026-08-18"

    • "ce-user-management-2026-07-13"

    • "mid-conversation-output-config-2026-07-01"

    • "thinking-binding-controls-2026-08-01"

    • "mid-conversation-system-clear-at-2026-08-21"

• "anthropic-workspace-id": optional string

Body parameters

• ca_certificate_pem: string

  PEM-encoded X.509 CA certificate. Must contain exactly one certificate and no private-key material. Maximum 8KB.

  maxLength: 8192

Returns

• BetaTunnelCertificate object

  A CA certificate attached to a tunnel.

  • type: "tunnel_certificate"

  • id: string

    Unique identifier for the certificate, prefixed with tcrt_.

  • archived_at: string or null

    A timestamp in RFC 3339 format

    format: date-time

  • created_at: string

    A timestamp in RFC 3339 format

    format: date-time

  • expires_at: string or null

    A timestamp in RFC 3339 format

    format: date-time

  • fingerprint: string

    Lowercase hex SHA-256 fingerprint of the certificate's DER encoding.

  • tunnel_id: string

    ID of the tunnel the certificate is registered against.

Example

curl https://api.anthropic.com/v1/tunnels/$TUNNEL_ID/certificates \
    -H 'Content-Type: application/json' \
    -H 'anthropic-version: 2023-06-01' \
    -H 'anthropic-beta: mcp-tunnels-2026-06-22' \
    -H "X-Api-Key: $ANTHROPIC_API_KEY" \
    -d '{
          "ca_certificate_pem": "ca_certificate_pem"
        }'

Response (200)

{
  "id": "id",
  "archived_at": "2019-12-27T18:11:19.117Z",
  "created_at": "2019-12-27T18:11:19.117Z",
  "expires_at": "2019-12-27T18:11:19.117Z",
  "fingerprint": "fingerprint",
  "tunnel_id": "tunnel_id",
  "type": "tunnel_certificate"
}