OpenResponses API

The Gateway can serve an OpenResponses-compatible POST /v1/responses endpoint. It is disabled by default and shares its port with the Gateway (WS + HTTP multiplex): http://<gateway-host>:<port>/v1/responses.

Requests run as a normal Gateway agent run (same codepath as openclaw agent), so routing, permissions, and config match your Gateway.

Enable or disable with gateway.http.endpoints.responses.enabled. When enabled, the same compatibility surface also serves GET /v1/models, GET /v1/models/{id}, POST /v1/embeddings, and POST /v1/chat/completions.

Authentication, security, and routing

Operational behavior matches OpenAI Chat Completions:

• Auth path matches gateway.auth.mode: shared-secret (token/password) uses Authorization: Bearer <token-or-password>; trusted-proxy uses identity-aware proxy headers (same-host loopback proxies need gateway.auth.trustedProxy.allowLoopback = true, with a same-host direct fallback via gateway.auth.password / OPENCLAW_GATEWAY_PASSWORD when no Forwarded/X-Forwarded-*/X-Real-IP header is present); none on private ingress needs no auth header. See Trusted proxy auth.
• Treat the endpoint as full operator access to the gateway instance.
• Shared-secret auth modes ignore a narrower bearer-declared x-openclaw-scopes and restore the full default operator scope set: operator.admin, operator.approvals, operator.pairing, operator.read, operator.talk.secrets, operator.write. Chat turns on this endpoint are treated as owner-sender turns.
• Trusted identity-bearing HTTP modes (trusted-proxy, or gateway.auth.mode="none") honor x-openclaw-scopes when present, otherwise fall back to the operator default scope set. Owner semantics are lost only when the caller explicitly narrows scopes and omits operator.admin.
• Select agents with model: "openclaw", "openclaw/default", "openclaw/<agentId>", or the x-openclaw-agent-id header.
• Use x-openclaw-model to override the selected agent's backend model (requires operator.admin on identity-bearing auth paths).
• Use x-openclaw-session-key for explicit session routing (rejected with 400 invalid_request_error if it uses a reserved namespace: subagent:, cron:, acp:).
• Use x-openclaw-message-channel for a non-default synthetic ingress channel context.

For the canonical explanation of agent-target models, openclaw/default, embeddings pass-through, and backend model overrides, see OpenAI Chat Completions.

See Operator scopes and Security.

Session behavior

By default the endpoint is stateless per request (a new session key is generated each call).

If the request includes an OpenResponses user string, the Gateway derives a stable session key from it so repeated calls can share an agent session.

previous_response_id reuses the earlier response's session when the request stays within the same agent/user/requested-session scope (matched by auth subject, agent id, and x-openclaw-session-key).

Request shape

Items (input)

message

Roles: system, developer, user, assistant.

• system and developer are appended to the system prompt.
• The most recent user or function_call_output item becomes the "current message."
• Earlier user/assistant messages are included as history for context.

function_call_output (turn-based tools)

Send tool results back to the model:

{
  "type": "function_call_output",
  "call_id": "call_123",
  "output": "{\"temperature\": \"72F\"}"
}

reasoning and item_reference

Accepted for schema compatibility but ignored when building the prompt.

Tools (client-side function tools)

Provide tools with tools: [{ type: "function", name, description?, parameters? }].

If the agent calls a tool, the response returns a function_call output item. Send a follow-up request with function_call_output to continue the turn.

For tool_choice: "required" and function-pinned tool_choice, the endpoint narrows the exposed client function-tool set, instructs the runtime to call a client tool before responding, and rejects the turn if it does not include a matching structured client-tool call, matching the /v1/chat/completions contract. Non-streaming requests return 502 with an api_error; streaming requests emit a response.failed event.

Images (input_image)

Supports base64 or URL sources:

{
  "type": "input_image",
  "source": { "type": "url", "url": "https://example.com/image.png" }
}

Allowed MIME types (default): image/jpeg, image/png, image/gif, image/webp, image/heic, image/heif. Max size (default): 10MB.

Files (input_file)

Supports base64 or URL sources:

{
  "type": "input_file",
  "source": {
    "type": "base64",
    "media_type": "text/plain",
    "data": "SGVsbG8gV29ybGQh",
    "filename": "hello.txt"
  }
}

Allowed MIME types (default): text/plain, text/markdown, text/html, text/csv, application/json, application/pdf. Max size (default): 5MB.

Current behavior:

• File content is decoded and added to the system prompt, not the user message, so it stays ephemeral (not persisted in session history).
• Decoded file text is wrapped as untrusted external content before it is added, so file bytes are treated as data, not trusted instructions. The injected block uses explicit boundary markers (<<<EXTERNAL_UNTRUSTED_CONTENT id="...">>> / <<<END_EXTERNAL_UNTRUSTED_CONTENT id="...">>>) and a Source: External metadata line. It intentionally omits the long SECURITY NOTICE: banner to preserve prompt budget; the boundary markers and metadata still apply.
• PDFs are parsed for text first. If little text is found, the first pages are rasterized into images and passed to the model, and the injected file block uses the placeholder [PDF content rendered to images].

PDF parsing is provided by the bundled document-extract plugin, which uses clawpdf and its packaged PDFium WebAssembly runtime for text extraction and page rendering.

URL fetch defaults:

• files.allowUrl: true
• images.allowUrl: true
• maxUrlParts: 8 (total URL-based input_file + input_image parts per request)
• Requests are guarded (DNS resolution, private IP blocking, redirect caps, timeouts).
• Optional hostname allowlists are supported per input type (files.urlAllowlist, images.urlAllowlist): exact host ("cdn.example.com") or wildcard subdomains ("*.assets.example.com", does not match the apex). Empty or omitted allowlists mean no hostname allowlist restriction.
• To disable URL-based fetches entirely, set files.allowUrl: false and/or images.allowUrl: false.

File + image limits (config)

Defaults can be tuned under gateway.http.endpoints.responses:

{
  gateway: {
    http: {
      endpoints: {
        responses: {
          enabled: true,
          maxBodyBytes: 20000000,
          maxUrlParts: 8,
          files: {
            allowUrl: true,
            urlAllowlist: ["cdn.example.com", "*.assets.example.com"],
            allowedMimes: [
              "text/plain",
              "text/markdown",
              "text/html",
              "text/csv",
              "application/json",
              "application/pdf",
            ],
            maxBytes: 5242880,
            maxChars: 60000,
            maxRedirects: 3,
            timeoutMs: 10000,
            pdf: {
              maxPages: 4,
              maxPixels: 4000000,
              minTextChars: 200,
            },
          },
          images: {
            allowUrl: true,
            urlAllowlist: ["images.example.com"],
            allowedMimes: [
              "image/jpeg",
              "image/png",
              "image/gif",
              "image/webp",
              "image/heic",
              "image/heif",
            ],
            maxBytes: 10485760,
            maxRedirects: 3,
            timeoutMs: 10000,
          },
        },
      },
    },
  },
}

Defaults when omitted:

HEIC/HEIF input_image sources are normalized to JPEG before provider delivery through the shared OpenClaw image processor (Rastermill), which falls back to a system converter (sips, ImageMagick, GraphicsMagick, or ffmpeg) for formats needing external codec support.

Security note: URL allowlists are enforced before fetch and on redirect hops. Allowlisting a hostname does not bypass private/internal IP blocking. For internet-exposed gateways, apply network egress controls in addition to app-level guards. See Security.

Streaming (SSE)

Set stream: true to receive Server-Sent Events:

• Content-Type: text/event-stream
• Each event line is event: <type> and data: <json>
• Stream ends with data: [DONE]

Event types currently emitted: response.created, response.in_progress, response.output_item.added, response.content_part.added, response.output_text.delta, response.output_text.done, response.content_part.done, response.output_item.done, response.completed, response.failed (on error).

Usage

usage is populated when the underlying provider reports token counts. OpenClaw normalizes common OpenAI-style aliases before those counters reach downstream status/session surfaces, including input_tokens / output_tokens and prompt_tokens / completion_tokens.

Errors

Errors use a JSON object like:

{ "error": { "message": "...", "type": "invalid_request_error" } }

Common cases: 400 invalid request body, 401 missing/invalid auth, 403 missing operator scope, 405 wrong method, 429 too many failed auth attempts (with Retry-After).

Examples

Non-streaming:

curl -sS http://127.0.0.1:18789/v1/responses \
  -H 'Authorization: Bearer YOUR_TOKEN' \
  -H 'Content-Type: application/json' \
  -H 'x-openclaw-agent-id: main' \
  -d '{
    "model": "openclaw",
    "input": "hi"
  }'

Streaming:

curl -N http://127.0.0.1:18789/v1/responses \
  -H 'Authorization: Bearer YOUR_TOKEN' \
  -H 'Content-Type: application/json' \
  -H 'x-openclaw-agent-id: main' \
  -d '{
    "model": "openclaw",
    "stream": true,
    "input": "hi"
  }'

Related

• OpenAI chat completions
• Operator scopes
• OpenAI