> ## Documentation Index > Fetch the complete documentation index at: https://docs.teamfollowup.ai/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > Use the public API base URL: https://api.teamfollowup.ai/api. > Authenticate public API requests with Authorization: Bearer YOUR_API_KEY. > Use product-owned terms: agents, campaigns, projects (GoHighLevel sub-accounts), contacts, calls, outcomes, skills, cadences, phone numbers. > Scope requests by locationId rather than projectName. > Read the guide linked from each API reference group before recommending an endpoint. # Add a voice > Add a voice to this agency's library so its agents can speak with it. Find the id with `POST /voices/search`. The voice is copied into every library the agency's agents are served from and still counts once against the allowance. Returns the whole library, so no follow-up read is needed. A voice already on the account (another agency added it, or this agency added and later removed it) is not added again: the request answers 409 `VOICE_ALREADY_SHARED`, spends nothing, and `references.voiceId` names the voice to select instead. It is already in `GET /voices` with `source: "shared"`. Required API key scope: `voices:write`. ## OpenAPI ````yaml /openapi.yaml post /api/agent-builder/voices/library openapi: 3.1.0 info: title: TFUAI Server API version: 1.0.0 description: >- API reference for the TFUAI SaaS server. All published endpoints are mounted under `/api`. Responses use a standard envelope: `{ "success": true, ... }` on success and `{ "success": false, "error": "..." }` on failure. Product API modules are being launched module by module. This spec currently exposes only contracted public modules. Authenticate public API requests with an API key in the `Authorization` header: `Authorization: Bearer YOUR_API_KEY`. servers: - url: https://api.teamfollowup.ai description: Production API origin. Public API paths are under /api. security: [] tags: - name: Agents description: Manage voice agents, campaigns, workflows, and outcomes. - name: Analytics description: >- Minimal, non-billing performance summary: volume, conversion, and pickup metrics. - name: Billing description: >- Billing for your own agency: balance, spend, transaction history, invoices and sub-account wallets; auto-recharge, rebilling, Credit Guard and Stripe customers; and, with the billing:charge scope, purchases and charges. - name: Calls description: Review calls, test runs, and execution history. - name: Campaign Workflows description: >- What runs after a call lands: for each outcome (booked, opted out, asked for a callback…), an ordered chain of actions — tag the contact, move a pipeline stage, send an SMS, book an appointment. Stored as a graph: `nodes` are the actions, `edges` say what follows what, and `dispositionEntries` maps each outcome to the node its chain starts at. **Pick the narrowest endpoint that does the job.** | To | Call | | | --- | --- | --- | | See what fires per outcome | `GET .../workflow/digest` | Reads as plain text, no graph walking | | Add steps to an outcome | `POST .../outcomes/{outcome}/nodes` | Server derives node ids, edge ids, handles, layout | | Change a message, tag or setting | `PATCH .../workflow` | Merges; carries no graph, so it cannot damage one | | Remove one step | `DELETE .../nodes/{nodeId}` | Also re-links the chain around it | | Author or replace the whole graph | `PUT .../workflow` | Replaces everything you send | `PUT` is the only one that can re-wire, position nodes, build an `if`, save an unconfigured draft, or copy a whole workflow — and the only one that can overwrite a change someone else made after you read it. Use it when you are genuinely authoring the graph, and send `expectedVersion` when you do. For everything else the narrower endpoints are both easier and safer. - name: Contacts description: Contact list, filters, contact call history, and do-not-call actions. - name: GHL description: CRM variables and contact helpers used by agent and campaign setup flows. - name: Phone Numbers description: >- Caller ID pool, number search, assignment, movement, and release endpoints. - name: Power Dialer description: >- Power Dialer queue, lead cadence, callback, parked lead, and campaign schedule endpoints. - name: Projects description: >- Project management endpoints: list, update, disconnect, configure project campaigns, and validate setup. - name: Skills and Tools description: Manage reusable agent behaviors and in-call tool descriptions. - name: Split Testing description: >- Split live campaign traffic across agent variants and shift the weights between them. - name: Voices description: Voice catalogue endpoints for choosing the voice used by an agent. paths: /api/agent-builder/voices/library: post: tags: - Voices summary: Add a voice description: >- Add a voice to this agency's library so its agents can speak with it. Find the id with `POST /voices/search`. The voice is copied into every library the agency's agents are served from and still counts once against the allowance. Returns the whole library, so no follow-up read is needed. A voice already on the account (another agency added it, or this agency added and later removed it) is not added again: the request answers 409 `VOICE_ALREADY_SHARED`, spends nothing, and `references.voiceId` names the voice to select instead. It is already in `GET /voices` with `source: "shared"`. Required API key scope: `voices:write`. operationId: add-voice-to-library requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/VoicesAddVoiceRequest' examples: default: value: providerVoiceId: EXAVITQu4vr4xnSDxMaL displayName: Sarah (warm) responses: '201': description: Voice added. The full library is returned. content: application/json: schema: $ref: '#/components/schemas/VoicesLibraryResponse' examples: default: value: success: true voices: - providerVoiceId: EXAVITQu4vr4xnSDxMaL displayName: Sarah (warm) addedAt: '2026-09-04T11:20:00.000Z' voiceIds: - custom_voice_9b1f2a7c4d3e5f6a8b0c1d2e3f used: 1 limit: 5 remaining: 4 '400': description: >- The request is malformed (`BadRequest`), or the library refused it (`VALIDATION`), for example because the voice is already in your library. content: application/json: schema: $ref: '#/components/schemas/VoicesErrorResponse' examples: validation: value: success: false error: VALIDATION message: That voice is already in your library. badRequest: value: success: false error: BadRequest message: voiceId required '401': description: Missing or invalid authentication. content: application/json: schema: $ref: '#/components/schemas/VoicesErrorResponse' examples: default: value: success: false error: Unauthorized message: Authentication required. '403': description: Authenticated but not permitted to use the voice endpoints. content: application/json: schema: $ref: '#/components/schemas/VoicesErrorResponse' examples: default: value: success: false error: Forbidden message: You do not have access to voice catalogue endpoints. '404': description: >- No voice with that `providerVoiceId` in the provider's public library. content: application/json: schema: $ref: '#/components/schemas/VoicesErrorResponse' examples: default: value: success: false error: NOT_FOUND message: We could not find that voice. Check the ID and try again. '409': description: >- The voice cannot be added as asked. `VOICE_ALLOWANCE`: the plan's voice allowance is used up; remove a voice or upgrade. `VOICE_CAPACITY`: new voices are temporarily unavailable; contact support. `VOICE_ALREADY_SHARED`: the voice is already on the account, so nothing was added or spent; select `references.voiceId` on the agent instead. content: application/json: schema: $ref: '#/components/schemas/VoicesErrorResponse' examples: allowance: value: success: false error: VOICE_ALLOWANCE message: >- Your plan includes 5 custom voices. Remove one or upgrade to add another. capacity: value: success: false error: VOICE_CAPACITY message: >- New voices are temporarily unavailable. Contact support and we will sort it out. alreadyShared: value: success: false error: VOICE_ALREADY_SHARED message: >- That voice is already on your account. Pick it from the shared list. references: voiceId: custom_voice_9b1f2a7c4d3e5f6a8b0c1d2e3f '429': description: Rate limit exceeded. content: application/json: schema: $ref: '#/components/schemas/VoicesErrorResponse' examples: default: value: success: false error: TooManyRequests message: Too many requests, please try again later. '500': description: Unexpected server error. content: application/json: schema: $ref: '#/components/schemas/VoicesErrorResponse' examples: default: value: success: false error: InternalError message: Unexpected server error. security: - ApiKeyAuth: [] x-codeSamples: - lang: bash label: cURL source: |- curl --request POST \ --url https://api.teamfollowup.ai/api/agent-builder/voices/library \ --header 'Authorization: Bearer YOUR_API_KEY' \ --header 'Content-Type: application/json' \ --data '{ "providerVoiceId": "EXAVITQu4vr4xnSDxMaL", "displayName": "Sarah (warm)" }' components: schemas: VoicesAddVoiceRequest: type: object additionalProperties: false required: - providerVoiceId properties: providerVoiceId: type: string minLength: 1 description: The provider voice id to add, as returned by the search. example: EXAVITQu4vr4xnSDxMaL displayName: type: string minLength: 1 maxLength: 200 description: >- What to call this voice in the picker. Defaults to the provider's own name. example: Sarah (warm) VoicesLibraryResponse: type: object additionalProperties: false required: - success - voices - used - limit - remaining properties: success: type: boolean voices: type: array items: $ref: '#/components/schemas/VoicesLibraryVoice' used: type: integer minimum: 0 description: Voices currently added. example: 1 limit: type: - integer - 'null' minimum: 0 description: How many voices this account may add. Null means unlimited. example: 5 remaining: type: - integer - 'null' minimum: 0 description: >- Voices still addable. Null whenever `limit` is null: an unlimited allowance has no remainder, and reporting a number here would be inventing one. example: 4 VoicesErrorResponse: type: object additionalProperties: {} required: - success - error - message properties: success: type: boolean error: type: string description: >- Machine-readable error code. The catalogue reads answer `BadRequest` and `NotFound`. The voice library answers `VALIDATION`, `NOT_FOUND`, `FORBIDDEN`, `VOICE_ALLOWANCE` (the plan's voice allowance is used up), `VOICE_CAPACITY` (new voices are temporarily unavailable) and `VOICE_ALREADY_SHARED` (the voice is already on the account; see `references`). example: NotFound message: type: string description: Human-readable explanation safe to show to an operator. example: Voice "custom_voice_missing" not found. references: type: object additionalProperties: false description: >- Sent only with `VOICE_ALREADY_SHARED`: what to use instead of adding. properties: voiceId: type: string description: >- The id of the voice already on the account. Select it on the agent rather than adding the voice again. example: custom_voice_9b1f2a7c4d3e5f6a8b0c1d2e3f VoicesLibraryVoice: type: object additionalProperties: false required: - providerVoiceId - displayName - addedAt - voiceIds description: One voice the agency added for itself. properties: providerVoiceId: type: string description: >- The voice id as the speech provider knows it. This is the id to send when removing the voice or asking what removing it would affect. example: EXAVITQu4vr4xnSDxMaL displayName: type: - string - 'null' description: >- What this voice is called in the picker. Null when the provider's own name is used. example: Sarah (warm) addedAt: type: - string - 'null' format: date-time example: '2026-09-04T11:20:00.000Z' voiceIds: type: array items: type: string description: >- The ids to select this voice on an agent. Plural because the voice is held in every library the agency's agents are served from, and only the copy in a given agent's library will play. It still counts as one voice against the allowance, however many copies it takes. example: - custom_voice_9b1f2a7c4d3e5f6a8b0c1d2e3f securitySchemes: ApiKeyAuth: type: http scheme: bearer bearerFormat: API key description: 'Send your API key as `Authorization: Bearer YOUR_API_KEY`.' ````