> ## 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. # Get a call's signals > What was noticed on one call: the signals raised and the observations made. A signal is a symptom noticed on a call, not a diagnosed issue: the issues say where a problem is, why, and what to change. ## OpenAPI ````yaml /api-reference/openapi.json get /v1/agents/{agentId}/calls/{callId}/signals openapi: 3.1.0 info: title: SignalMD API version: 1.0.0 description: >- SignalMD 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://api.signalmd.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 SignalMD 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}/calls/{callId}/signals: get: tags: - Calls summary: Get a call's signals description: >- What was noticed on one call: the signals raised and the observations made. A signal is a symptom noticed on a call, not a diagnosed issue: the issues say where a problem is, why, and what to change. operationId: getCallSignals 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: string format: uuid description: The call's id in SignalMD (not the platform's call id). required: true description: The call's id in SignalMD (not the platform's call id). name: callId in: path responses: '200': description: The call's signals. content: application/json: schema: $ref: '#/components/schemas/CallSignals' '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://api.signalmd.dev/v1/agents/6f1d2c3b-4a5e-4f60-8b7a-9c0d1e2f3a4b/calls/0b9e8d7c-6f5a-4b3c-9d2e-1f0a9b8c7d6e/signals" \ -H "Authorization: Bearer $SIGNAL_API_KEY" components: schemas: CallSignals: type: object properties: object: type: string enum: - call_signals callId: type: string format: uuid pattern: >- ^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$ example: 3f1c2d4e-5a6b-4c7d-8e9f-0a1b2c3d4e5f detected: type: - array - 'null' items: $ref: '#/components/schemas/DetectedSignal' description: The signals raised on the call. Null until the call is analysed. observations: type: - array - 'null' items: $ref: '#/components/schemas/SignalObservation' description: >- Moments in the call checked against how the agent is configured. Evidence for an issue, never an issue on their own. Null when the call has not been read this way. required: - object - callId - detected - observations 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: credits description: >- credits when the workspace's monthly credits are used up, or agents when the plan's agent limit is reached. activity: type: string enum: - observation - testing - chat example: testing description: >- With metric credits: what the request would have spent them on. observation is analysing calls, testing is test runs, chat is the copilot. requested: type: integer example: 18 description: >- With metric credits: the credits the request needed to start. limit: type: integer description: 'The plan''s limit: the month''s credits, or its agents.' used: type: integer description: How much of the limit is used this month. 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. proposalId: type: string format: uuid description: >- Present when code is criteria_locked: the pending criteria proposal the change was filed as. A person approves or rejects it. 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 DetectedSignal: type: object properties: code: type: string description: >- Stable code of the signal, or `checklist..` for a stored checklist answer. title: type: string description: How it reads on this call; can name a place ("lookup failed"). severity: type: string enum: - info - warn - critical klass: type: string enum: - technical - flow - content - behaviour description: >- Which kind of fix it points at: `technical` (an engineer), `flow` (whoever owns the conversation design), `content` (whoever owns prompts and knowledge), or `behaviour` (something callers do that is worth knowing but is not a defect). confidence: type: number description: 0 to 1. location: type: object properties: kind: type: string enum: - node - edge - tool - global description: >- A step of the flow, a transition between two steps, a tool, or the whole call. id: type: string description: >- The step id, `from->to` for a transition, the tool name, or `global`. label: type: string description: How the place reads to a person. required: - kind - id - label detail: type: string description: >- What was measured or read. On a `checklist.*` signal, that a model judged it from what was said. cause: type: - object - 'null' properties: code: type: string description: Stable key for the cause. label: type: string description: How the cause reads to a person. detail: type: - string - 'null' description: What in the trace says so. required: - code - label - detail description: >- Why it happened, read from what the trace shows around it. Null when no cause was read. turnIndex: type: - integer - 'null' evidenceQuote: type: - string - 'null' description: The words at the moment, clipped. required: - code - title - severity - klass - confidence - location - detail - cause - turnIndex - evidenceQuote example: code: tool_timeout title: Tool timed out severity: critical klass: technical confidence: 0.9 location: kind: tool id: check_availability label: check_availability detail: check_availability returned nothing after 9.4 s. cause: code: tool_latency label: Slow tool detail: null turnIndex: 7 evidenceQuote: Let me check what we have open next week. SignalObservation: type: object properties: rule: type: string description: Stable code of the check that produced it. kind: type: string enum: - conformance - omission - checklist description: >- `conformance`: something the agent said against what its configuration expects. `omission`: something its configuration expected that did not happen. `checklist`: a stored checklist answer. label: type: string turnIndex: type: integer description: The turn it is about. detail: type: string description: What was expected, found or broken. basis: type: string enum: - checked - inferred description: >- `checked`: confirmed against the call record. `inferred`: a reading of the conversation, not confirmed. required: - rule - kind - label - turnIndex - detail - basis 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.