> ## Documentation Index > Fetch the complete documentation index at: https://talktohumans.app/docs/llms.txt > Use this file to discover all available pages before exploring further. # Create signals > Creates one or multiple signals on contacts ## OpenAPI ````yaml /developers/openapi.yaml post /v1/signals openapi: 3.0.3 info: title: TalkToHumans Public API version: 1.0.0 license: name: Proprietary description: > Read and organize the LinkedIn organization data your team already manages in TalkToHumans: accounts, contacts, signals, content, tags, notes, custom fields, sequence state, conversations, templates, and views. servers: - url: https://api.talktohumans.app description: TalkToHumans API security: - bearerAuth: [] tags: - name: Organization description: Organization details for the current API key. - name: LinkedIn description: LinkedIn accounts, contacts, companies, and conversations. - name: Activity description: Activity for organization reporting. - name: Enrich description: Profile enrichment for LinkedIn contacts and companies. - name: Views description: Saved TalkToHumans views. - name: Sequences description: Sequences of contacts and conversations. - name: Templates description: Message and sequence templates. - name: Custom fields description: Custom fields for contacts and companies. - name: Tags description: Tags for contacts and companies. - name: Content description: LinkedIn posts and comments, and the people who engage with them. - name: Agents description: Playbooks and feedback for AI agents, shared with the MCP. paths: /v1/signals: post: tags: - LinkedIn summary: Create signals description: Creates one or multiple signals on contacts operationId: createSignals requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/CreateSignalsRequest' example: account_id: '42' signals: - contact_id: '123' signal_type: custom:webinar_attended text: Attended the pricing webinar occurred_at: '2026-10-28T17:00:00Z' key: webinar-2026-10-28:123 responses: '200': description: >- Signals written. Invalid ones are listed in `errors` and the others are written. content: application/json: schema: $ref: '#/components/schemas/CreateSignalsEnvelope' example: data: created: 1 updated: 0 errors: [] '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/AccountScopedForbidden' '429': $ref: '#/components/responses/RateLimited' '500': $ref: '#/components/responses/InternalServerError' components: schemas: CreateSignalsRequest: type: object additionalProperties: false required: - account_id - signals properties: account_id: type: string description: LinkedIn account ID returned by `GET /v1/accounts`. pattern: ^[1-9][0-9]*$ signals: type: array minItems: 1 maxItems: 500 items: $ref: '#/components/schemas/CreateSignalInput' CreateSignalsEnvelope: type: object additionalProperties: false required: - data properties: data: $ref: '#/components/schemas/CreateSignalsResponse' CreateSignalInput: type: object additionalProperties: false required: - signal_type - text - key properties: contact_id: type: string description: >- Contact ID from `GET /v1/contacts`. Provide exactly one of `contact_id` or `linkedin_url`; the contact must already be in the account. pattern: ^[1-9][0-9]*$ linkedin_url: type: string description: >- LinkedIn profile URL of a contact of the account. Provide exactly one of `contact_id` or `linkedin_url`. signal_type: type: string pattern: ^custom:[a-z0-9_]{1,40}$ example: custom:event_attended text: type: string minLength: 1 maxLength: 280 occurred_at: type: string format: date-time description: When it happened, not in the future. Defaults to now. key: type: string minLength: 1 maxLength: 200 description: >- Your own unique key for this signal. Sending the same key again updates its signal instead of adding one. CreateSignalsResponse: type: object additionalProperties: false required: - created - updated - errors properties: created: type: integer updated: type: integer errors: type: array description: >- Signals that were not written, by their index in `signals`. The others were. items: $ref: '#/components/schemas/CreateSignalError' Error: type: object additionalProperties: false required: - code - message properties: code: type: string description: Machine-readable error code. enum: - unauthorized - forbidden - not_found - bad_request - internal_error - conflict - rate_limit_exceeded - account_shared_access_required - linkedin_not_connected - workspace_setup_required - billing_payment_failed - billing_subscription_incomplete - billing_subscription_expired - billing_grace_period - billing_feature_not_available - billing_insufficient_credits - billing_invalid - enrichment_failed - enrichment_in_progress - linkedin_profile_not_found message: type: string description: Human-readable error message. debug: type: string description: Development-only debug details. CreateSignalError: type: object additionalProperties: false required: - index - code - message properties: index: type: integer code: type: string enum: - invalid_signal - contact_not_found - key_conflict message: type: string responses: BadRequest: description: Invalid request. `message` explains what to fix. content: application/json: schema: $ref: '#/components/schemas/Error' example: code: bad_request message: >- field "account_id" must be a string, got number; IDs are strings, e.g. "42" Unauthorized: description: >- Missing, malformed, invalid, or retired API key, or an invalid or expired login access token. content: application/json: schema: $ref: '#/components/schemas/Error' examples: missingAuthorization: value: code: unauthorized message: Authorization header is required invalidAuthorizationFormat: value: code: unauthorized message: Authorization header must use Bearer scheme invalidAPIKey: value: code: unauthorized message: Invalid API key invalidAccessToken: value: code: unauthorized message: Invalid or expired access token AccountScopedForbidden: description: >- API access is not enabled for the organization, the API key cannot resolve to an active organization user, the login has no workspace yet, or the credential cannot access the requested LinkedIn account. content: application/json: schema: $ref: '#/components/schemas/Error' examples: accountSharedAccessRequired: summary: Requested account is not accessible to this credential value: code: account_shared_access_required message: >- This account is not shared-access enabled for API or MCP. Ask an admin to enable shared access before using this account from this credential. forbidden: value: code: forbidden message: you don't have access to this organization featureUnavailable: value: code: billing_feature_not_available message: >- Feature 'TalkToHumansAPI' is not available in your current plan insufficientCredits: value: code: billing_insufficient_credits message: Insufficient credits apiKeyPrincipalInvalid: value: code: forbidden message: >- This API key is no longer linked to an active organization user. Ask an organization admin to regenerate it workspaceSetupRequired: value: code: workspace_setup_required message: >- This TalkToHumans sign-in has no workspace yet. Open https://app.talktohumans.app, sign in with the same email to finish setting up TalkToHumans, then try again. RateLimited: description: >- Rate limit exceeded. Public routes allow 50 requests per 10 seconds per IP and endpoint. headers: Retry-After: description: Seconds to wait before retrying the request. schema: type: integer content: application/json: schema: $ref: '#/components/schemas/Error' example: code: rate_limit_exceeded message: Rate limit exceeded InternalServerError: description: Unexpected server error. content: application/json: schema: $ref: '#/components/schemas/Error' example: code: internal_error message: An internal error occurred securitySchemes: bearerAuth: type: http scheme: bearer description: > Pass `Authorization: Bearer `, where the credential is either: - an API key (`sk_…`), generated by an organization admin in Settings, for scripts and automation; - an access token from `tth auth login` (the TalkToHumans CLI), which any member of the workspace can use. Both resolve to the same organization and user. A login token acts in the user's workspace: one with no workspace yet returns `403 workspace_setup_required`, and one in several workspaces returns `403 forbidden` (use an API key instead). ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.