> ## Documentation Index > Fetch the complete documentation index at: https://docs.sempera.org/llms.txt > Use this file to discover all available pages before exploring further. # Verified text Assistant ingress > Server-to-server signed text ingress. Requires webhook-id, webhook-timestamp and webhook-signature over the raw body. Closed unless the channel is configured. ## OpenAPI ````yaml https://api.sempera.org/openapi.json post /v1/webhooks/text-assistant openapi: 3.1.0 info: title: Sempera API version: 1.0.0 description: >- The Sempera API: agents, versions, sessions, calls, phone numbers, tools, integrations, knowledge, tests, evals, workspaces, API keys and webhooks, under one hostname. Read /llms.txt for the guide map. contact: name: Sempera url: https://sempera.org email: hello@sempera.org servers: - url: https://api.sempera.org security: [] tags: - name: OAuth description: >- OAuth discovery, client registration and authorization with PKCE. Revoke grants through Connected clients. - name: Operations description: >- Platform-operator attestations in the designated internal operations workspace only. - name: Webhook ingress description: >- Server-to-server provider callbacks with provider-specific proof, not workspace API keys. - name: Dialing pools description: Owned caller ID pools and side-effect-free selection previews. - name: Messaging description: >- Channel setup and stored conversations; transport activation remains gated. - name: Memory description: Workspace-scoped agent memory configuration and records. - name: Phone description: >- The personal phone plan: previewed, approved calls and texts on one number. - name: Batches description: Consent-bound outbound call batches and their recorded attempts. - name: SMS description: Workspace text conversations, guarded sends and human handoff. - name: Assistant description: >- Owner-session text Assistant settings, mobile linking and the owner's own thread. - name: Experiments description: Observed comparisons between published versions of an agent. - name: Meta description: The API's own front door. - name: Authentication description: Credential classes and scopes. - name: Agents description: 'The core product object: draft, preview, publish, versions.' - name: Sessions description: Channel-neutral conversations, and minting Web voice sessions. - name: Calls description: Phone calls (telephony lifecycle). - name: Phone numbers description: Number-to-agent binding. - name: Tools description: Workspace-level capabilities an agent attaches. - name: Integrations description: Provider connections. - name: Compatibility description: Observed read-only compatibility facades over Sempera canonical stores. - name: Snippets description: >- Versioned workspace code a code tool pins; published versions never change. - name: Knowledge description: Documents an agent answers from. - name: Personas description: Compiled agent identity, one persona per agent. - name: Tests description: Scripted scenarios before deployment. - name: Evals description: Judging completed conversations. - name: Alerts description: An organization's metric alert rules and each rule's trigger log. - name: Workspaces description: The tenant boundary. - name: Credits description: >- A workspace's credit balance and history, read only. Credits pay for building, never for live calls. - name: Automations description: >- Triggers: an event Sempera emits, conditions on it, and one action (a signed webhook or an owner email). - name: Platform description: Deployment identity and capacity, for CI and certification. - name: Organizations description: The membership and billing umbrella. - name: API keys description: Minting and revoking credentials. - name: Webhooks description: Sempera-signed outbound events. - name: Connected clients description: >- Every outside client connected to a workspace, whichever way it signed in, with scopes, last use and revocation. - name: MCP description: >- The MCP endpoint, per-client setup answers, and the revocable connections an owner gives outside AI clients. - name: Models description: Sempera's customer-eligible model catalog. - name: Prompts description: Stored prompts a workspace saves and reuses. - name: Scenarios description: >- An agent's scenarios (situations): create, archive, restore, copy and history. - name: Widgets description: Website widgets, web chat threads and custom components. - name: Citation schemas description: >- The outcome fields frozen with each published version, and how well they are captured. - name: Developer settings description: Developer-facing workspace settings. - name: Contacts description: Workspace contact grouping, resolution and the shared contact schema. - name: Voices description: >- The workspace voice collection: saved cleared voices, desk ratings, team sharing and professional clone preparation. paths: /v1/webhooks/text-assistant: post: tags: - Webhook ingress summary: Verified text Assistant ingress description: >- Server-to-server signed text ingress. Requires webhook-id, webhook-timestamp and webhook-signature over the raw body. Closed unless the channel is configured. operationId: receiveTextAssistantMessage parameters: [] requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/TextProviderEvent' responses: '202': description: Accepted content: application/json: schema: $ref: '#/components/schemas/TextProviderReceipt' '400': description: Validation failed content: application/json: schema: $ref: '#/components/schemas/Error' '404': description: Not found (or not in your scope) content: application/json: schema: $ref: '#/components/schemas/Error' '409': description: Conflict content: application/json: schema: $ref: '#/components/schemas/Error' '429': description: Rate limited (Retry-After) content: application/json: schema: $ref: '#/components/schemas/Error' '503': description: Channel unavailable content: application/json: schema: $ref: '#/components/schemas/Error' security: - textSignature: [] components: schemas: TextProviderEvent: type: object properties: api_version: const: v3 webhook_version: const: '2026-02-03' event_id: type: string event_type: type: string data: type: object properties: id: type: string chat: type: object properties: id: type: string is_group: const: false owner_handle: type: object properties: handle: type: string is_me: const: true required: - handle - is_me required: - id - is_group - owner_handle sender_handle: type: object properties: handle: type: string pattern: ^\+[1-9][0-9]{7,14}$ is_me: const: false required: - handle - is_me direction: const: inbound service: const: iMessage parts: type: array minItems: 1 items: type: object properties: type: const: text value: type: string required: - type - value required: - id - chat - sender_handle - direction - service - parts description: >- Required for message.received. Other event types are acknowledged without processing data. required: - api_version - webhook_version - event_id - event_type TextProviderReceipt: type: object properties: accepted: const: true required: - accepted Error: type: object required: - error properties: error: type: object required: - code - message - request_id properties: code: type: string enum: - AGENT_ENV_UNPINNED - CALL_RL_PLAN_ALLOWANCE - CALL_RL_PLAN_CONCURRENCY - CALL_RL_PLAN_DAILY - CALL_RL_PLAN_DAILY_MINUTES - CALL_RL_PLAN_HOURLY - PHONE_AGENT_UNPINNED - PHONE_APPROVAL_EXPIRED - PHONE_APPROVAL_INVALID - PHONE_APPROVAL_REQUIRED - PHONE_COST_UNKNOWN - PHONE_DESTINATION_BLOCKED - PHONE_FUNDING_NOT_LIVE - PHONE_NUMBER_MISSING - PHONE_OUTSIDE_HOURS - PHONE_PLAN_INACTIVE - PHONE_RECIPIENT_OPTED_OUT - SMS_RL_PLAN_ALLOWANCE - SMS_RL_PLAN_DAILY - SMS_RL_PLAN_HOURLY - authentication_required - capability_unavailable - conflict - credits_exhausted - credits_unavailable - csrf_failed - forbidden - gone - idempotency_key_reused - insufficient_scope - internal_error - invalid_credential - method_not_allowed - not_found - owner_setup_required - payload_too_large - provider_failed - provider_timeout - rate_limited - service_unavailable - validation_failed - workspace_suspended message: type: string request_id: type: string field: type: string scope: type: string reason: type: string additionalProperties: true securitySchemes: textSignature: type: apiKey in: header name: webhook-signature description: >- Signature over webhook-id.webhook-timestamp.raw_body; both companion headers are required. 300-second tolerance. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.