OpenResponses API

OpenClaw’s Gateway can serve an OpenResponses-compatible POST /v1/responses endpoint.

This endpoint is disabled by default. Enable it in config first.

• POST /v1/responses
• Same port as the Gateway (WS + HTTP multiplex): http://<gateway-host>:<port>/v1/responses

Under the hood, requests are executed as a normal Gateway agent run (same codepath as openclaw agent), so routing/permissions/config match your Gateway.

Authentication, security, and routing

Operational behavior matches OpenAI Chat Completions:

• use the matching Gateway HTTP auth path:
  • shared-secret auth (gateway.auth.mode="token" or "password"): Authorization: Bearer <token-or-password>
  • trusted-proxy auth (gateway.auth.mode="trusted-proxy"): identity-aware proxy headers from a configured trusted proxy source; same-host loopback proxies require explicit gateway.auth.trustedProxy.allowLoopback = true
  • private-ingress open auth (gateway.auth.mode="none"): no auth header
• treat the endpoint as full operator access for the gateway instance
• for shared-secret auth modes (token and password), ignore narrower bearer-declared x-openclaw-scopes values and restore the normal full operator defaults
• for trusted identity-bearing HTTP modes (for example trusted proxy auth or gateway.auth.mode="none"), honor x-openclaw-scopes when present and otherwise fall back to the normal operator default scope set
• select agents with model: "openclaw", model: "openclaw/default", model: "openclaw/<agentId>", or x-openclaw-agent-id
• use x-openclaw-model when you want to override the selected agent's backend model
• use x-openclaw-session-key for explicit session routing
• use x-openclaw-message-channel when you want a non-default synthetic ingress channel context

Auth matrix:

• gateway.auth.mode="token" or "password" + Authorization: Bearer ...
  • proves possession of the shared gateway operator secret
  • ignores narrower x-openclaw-scopes
  • restores the full default operator scope set: operator.admin, operator.approvals, operator.pairing, operator.read, operator.talk.secrets, operator.write
  • treats chat turns on this endpoint as owner-sender turns
• trusted identity-bearing HTTP modes (for example trusted proxy auth, or gateway.auth.mode="none" on private ingress)
  • honor x-openclaw-scopes when the header is present
  • fall back to the normal operator default scope set when the header is absent
  • only lose owner semantics when the caller explicitly narrows scopes and omits operator.admin

Enable or disable this endpoint with gateway.http.endpoints.responses.enabled.

The same compatibility surface also includes:

• GET /v1/models
• GET /v1/models/{id}
• POST /v1/embeddings
• POST /v1/chat/completions

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

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.

Request shape (supported)

The request follows the OpenResponses API with item-based input. Current support:

• input: string or array of item objects.
• instructions: merged into the system prompt.
• tools: client tool definitions (function tools).
• tool_choice: filter or require client tools.
• stream: enables SSE streaming.
• max_output_tokens: best-effort output limit (provider dependent).
• user: stable session routing.

Accepted but currently ignored:

• max_tool_calls
• reasoning
• metadata
• store
• truncation

Supported:

• previous_response_id: OpenClaw reuses the earlier response session when the request stays within the same agent/user/requested-session scope.

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", function: { name, description?, parameters? } }].

If the agent decides to call a tool, the response returns a function_call output item. You then send a follow-up request with function_call_output to continue the turn.

Images (input_image)

Supports base64 or URL sources:

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

Allowed MIME types (current): image/jpeg, image/png, image/gif, image/webp, image/heic, image/heif. Max size (current): 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 (current): text/plain, text/markdown, text/html, text/csv, application/json, application/pdf.

Max size (current): 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 like <<<EXTERNAL_UNTRUSTED_CONTENT id="...">>> / <<<END_EXTERNAL_UNTRUSTED_CONTENT id="...">>> and includes a Source: External metadata line.
• This file-input path intentionally omits the long SECURITY NOTICE: banner to preserve prompt budget; the boundary markers and metadata still stay in place.
• 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 the Node-friendly pdfjs-dist legacy build (no worker). The modern PDF.js build expects browser workers/DOM globals, so it is not used in the Gateway.

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"
  • Wildcard subdomains: "*.assets.example.com" (does not match 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: 200000,
            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:

• maxBodyBytes: 20MB
• maxUrlParts: 8
• files.maxBytes: 5MB
• files.maxChars: 200k
• files.maxRedirects: 3
• files.timeoutMs: 10s
• files.pdf.maxPages: 4
• files.pdf.maxPixels: 4,000,000
• files.pdf.minTextChars: 200
• images.maxBytes: 10MB
• images.maxRedirects: 3
• images.timeoutMs: 10s
• HEIC/HEIF input_image sources are accepted and normalized to JPEG before provider delivery.

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 (SSE):

• 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:

• 401 missing/invalid auth
• 400 invalid request body
• 405 wrong method

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
• OpenAI