> ## Documentation Index > Fetch the complete documentation index at: https://docs.signalmd.dev/llms.txt > Use this file to discover all available pages before exploring further. # List signals > For each signal code, how many of the agent's analysed calls in the window carry it, most calls first. A signal is a symptom noticed on a call, not a diagnosed issue: a common signal can have several causes or none worth fixing, and the issues say where a problem is, why, and what to change. ## OpenAPI ````yaml /api-reference/openapi.json get /v1/agents/{agentId}/signals openapi: 3.1.0 info: title: Signal API version: 1.0.0 description: >- Signal reads a voice agent's production calls and says what to fix, then tests whether the fix worked. This API exposes the same data the web app shows: agents, calls and their traces, signals, issues, versions and their comparisons, tests, and test runs. Authenticate with `Authorization: Bearer sig_...` (an API key from the API keys page). Read keys may call every `read` operation; write keys may also call `write` operations, within their monthly budget. Each operation's scope is in `x-signal-scope`. Errors share one envelope (`Error`), lists share one cursor scheme (`limit`, `cursor`, `hasMore`, `nextCursor`), and every response carries `Request-Id` and `RateLimit-*` headers. servers: - url: https://first-signal-api.fly.dev description: Production - url: http://localhost:43124 description: Local development security: - bearerAuth: [] tags: - name: Account description: Who the token belongs to and what it may do. - name: Agents description: Voice agents connected to the workspace. - name: Calls description: Production calls, their traces and per-call signals. - name: Signals description: What Signal noticed across calls. - name: Issues description: 'Problems worth fixing: where, why, and what to change.' - name: Versions description: Agent versions and how each one did. - name: Comparisons description: Stored comparisons between two versions. - name: Tests description: Tests, test sets, personas and coverage. - name: Runs description: Test runs and the attempts inside them. paths: /v1/agents/{agentId}/signals: get: tags: - Signals summary: List signals description: >- For each signal code, how many of the agent's analysed calls in the window carry it, most calls first. A signal is a symptom noticed on a call, not a diagnosed issue: a common signal can have several causes or none worth fixing, and the issues say where a problem is, why, and what to change. operationId: listSignals parameters: - schema: type: string format: uuid pattern: >- ^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$ example: 3f1c2d4e-5a6b-4c7d-8e9f-0a1b2c3d4e5f description: The agent's id. required: true description: The agent's id. name: agentId in: path - schema: type: integer description: Only calls taken by this agent version. required: false description: Only calls taken by this agent version. name: version in: query - schema: type: string format: date-time description: Only calls that started at or after this time. required: false description: Only calls that started at or after this time. name: startedAfter in: query - schema: type: string format: date-time description: Only calls that started before this time. required: false description: Only calls that started before this time. name: startedBefore in: query responses: '200': description: Every signal code seen in the window. content: application/json: schema: $ref: '#/components/schemas/SignalSummaryList' '400': description: 'Invalid request: a parameter or the body failed validation.' content: application/json: schema: $ref: '#/components/schemas/Error' '401': description: Missing, invalid or revoked credentials. content: application/json: schema: $ref: '#/components/schemas/Error' '403': description: Not permitted for this principal. content: application/json: schema: $ref: '#/components/schemas/Error' '404': description: >- The agent, or a resource under it, does not exist or is not visible to this key. content: application/json: schema: $ref: '#/components/schemas/Error' '429': description: Rate limited. See Retry-After. content: application/json: schema: $ref: '#/components/schemas/Error' '500': description: Server error. The message is generic; quote the request id. content: application/json: schema: $ref: '#/components/schemas/Error' x-codeSamples: - lang: bash label: curl source: >- curl "https://first-signal-api.fly.dev/v1/agents/6f1d2c3b-4a5e-4f60-8b7a-9c0d1e2f3a4b/signals" \ -H "Authorization: Bearer $SIGNAL_API_KEY" components: schemas: SignalSummaryList: type: object properties: object: type: string enum: - list data: type: array items: $ref: '#/components/schemas/SignalSummary' hasMore: type: boolean enum: - false description: 'Always false: every code is on one page.' nextCursor: type: 'null' analyzedCalls: type: integer description: 'Analysed calls in the window: the denominator of every `share`.' required: - object - data - hasMore - nextCursor - analyzedCalls Error: type: object properties: error: type: object properties: type: $ref: '#/components/schemas/ErrorType' code: type: string example: agent_not_found description: The specific reason; stable within v1. message: type: string example: Agent not found. param: type: - string - 'null' description: The request field at fault, for a validation error. requestId: type: - string - 'null' example: req_8c1f0e2b4a6d9e3f7a5c1b0d quota: type: object properties: metric: type: string example: test_calls description: analysed_calls, agents, copilot_messages or test_calls. limit: type: integer used: type: integer plan: type: string example: free_org description: The workspace's plan slug. upgradePath: type: string example: /billing description: Where in the web app the plan is changed. required: - metric - limit - used - plan - upgradePath description: >- Present when code is quota_exceeded: the plan limit the request would pass. required: - type - code - message - param - requestId required: - error example: error: type: not_found_error code: agent_not_found message: Agent not found. param: null requestId: req_8c1f0e2b4a6d9e3f7a5c1b0d SignalSummary: type: object properties: object: type: string enum: - signal_summary code: type: string description: >- The signal code. Pass it as `signal` to `GET /calls` to list the calls that carry it. title: type: string description: The code's name as issue titles and filters use it. klass: type: string enum: - technical - flow - content - behaviour description: >- The class most of these calls carry. A code can be classed differently on different calls. severity: type: string enum: - info - warn - critical description: >- The severity most of these calls carry. A code's severity can differ from call to call. calls: type: integer description: >- Analysed calls in the window with this signal, each counted once however often it fired. share: type: number description: '`calls` divided by `analyzedCalls`, 0 to 1.' required: - object - code - title - klass - severity - calls - share example: object: signal_summary code: tool_timeout title: Tool timed out klass: technical severity: critical calls: 15 share: 0.03 ErrorType: type: string enum: - invalid_request_error - authentication_error - budget_error - permission_error - not_found_error - conflict_error - rate_limit_error - api_error securitySchemes: bearerAuth: type: http scheme: bearer description: An API key (`sig_...`), or a session token from the web app. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.