# title: Create Tunnel Certificate url: https://platform.claude.com/docs/en/api/beta/tunnels/certificates/create

# 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 43 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"
  - "compact-2026-09-04"
"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

bash

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)

json

{
  "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"
}

spb doc-api