Cloud API Reference

The Prepatu Cloud API lets you manage flows, start voice sessions, and monitor usage without running your own backend.

Base URL: https://api.prepatu.io

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Authentication

Two authentication methods:

Method	Header	Used for
JWT Bearer	Authorization: Bearer <token>	Dashboard, account management
API Key	X-Prepatu-Key: pk_live_...	SDK integration, flow management, sessions

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Auth Endpoints

POST /auth/signup

Create a new account.

// Request
{ "email": "[email protected]", "password": "your-password" }

// Response 200
{ "access_token": "eyJ...", "token_type": "bearer" }

POST /auth/login

// Request
{ "email": "[email protected]", "password": "your-password" }

// Response 200
{ "access_token": "eyJ...", "token_type": "bearer" }

POST /auth/api-keys?label=my-app

Create an API key. Requires JWT auth.

// Response 201
{ "key": "pk_live_...", "label": "my-app" }

GET /auth/api-keys

List all API keys for the account. Requires JWT auth.

DELETE /auth/api-keys/{key_id}

Revoke an API key. Requires JWT auth.

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Flow Endpoints

Flows are VFDL YAML documents stored in the cloud. Each account can store multiple named flows.

POST /v1/flows

Upload a new flow.

// Request (API key or JWT)
{
  "name": "My Booking Flow",
  "yaml_content": "id: booking\nversion: \"1.0.0\"\n..."
}

// Response 201
{
  "id": "f-abc123...",
  "name": "My Booking Flow",
  "yaml_content": "...",
  "created_at": 1718000000.0
}

The server validates the YAML on upload — invalid YAML returns 422.

GET /v1/flows

List all flows for the account.

// Response 200
[
  { "id": "f-abc123", "name": "My Booking Flow", "created_at": 1718000000.0 },
  { "id": "f-def456", "name": "10 Questions", "created_at": 1718000100.0 }
]

GET /v1/flows/{flow_id}

Get a single flow including its YAML content.

DELETE /v1/flows/{flow_id}

Delete a flow.

GET /v1/flows/{flow_id}/json

Get the flow as parsed JSON (for the visual editor).

PUT /v1/flows/{flow_id}/json

Update a flow from JSON (the server serializes it back to YAML).

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Session Endpoints

POST /v1/sessions

Start a voice session. Returns a WebSocket URL to connect to.

// Request (API key required)
{
  "flow_id": "f-abc123",
  "context": { "user_name": "Alex" },
  "metadata": { "source": "web" }
}

// Response 200
{
  "session_token": "st_...",
  "ws_url": "wss://api.prepatu.io/v1/ws/st_...",
  "transport": "websocket",
  "credits_remaining": 197
}

Field	Description
flow_id	Optional — omit for a generic assistant session
context	Pre-fill flow variables before the flow starts
metadata	Forwarded to session hooks (analytics, logging)

GET /v1/sessions

List recent sessions (last 50).

// Response 200
[
  {
    "token_prefix": "st_abc12",
    "flow_id": "f-abc123",
    "started_at": 1718000000.0,
    "ended_at": 1718000120.0,
    "duration_secs": 120
  }
]

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Voice WebSocket

WS /v1/ws/{session_token}

Connect to a voice session. The session token authenticates the connection — no additional headers needed.

Once connected, the session follows the Prepatu Voice Protocol (PVP):

• Client → Server: Binary PCM16 audio frames + JSON control messages
• Server → Client: Binary PCM16 TTS audio + JSON flow messages

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Credits

GET /v1/credits/balance

// Response 200
{
  "balance_usd_cents": 197,
  "rate_per_minute_usd_cents": 3
}

New accounts receive $2.00 (200 cents) in free credits. Sessions are charged at $0.03/minute.

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Provider Keys

Bring your own STT/TTS/LLM keys to avoid using shared credits.

GET /v1/providers

// Response 200
{
  "stt_provider": "deepgram",
  "stt_api_key": null,
  "tts_provider": "deepgram",
  "tts_api_key": null,
  "llm_provider": "openrouter",
  "llm_api_key": null
}

null means the account uses Prepatu's shared keys (deducted from credits).

PATCH /v1/providers

Update provider keys (JWT auth required).

// Request
{
  "stt_api_key": "dg-...",
  "llm_api_key": "sk-or-..."
}

When you provide your own keys, those providers are not charged against your credits.

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Health

GET /health

{ "status": "ok", "service": "prepatu-cloud" }