First commit

apps/channel_gateway/app/adapters/base.py

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+from __future__ import annotations
+
+from typing import Protocol
+from app.schemas import GatewayRequest
+
+
+class ChannelAdapter(Protocol):
+    name: str
+    async def to_gateway_request(self, payload) -> GatewayRequest: ...

apps/channel_gateway/app/adapters/voice.py

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+from __future__ import annotations
+
+from app.schemas import BusinessContext, GatewayRequest, VoiceTranscript
+from app.settings import settings
+
+
+class VoiceAdapter:
+    name = 'voice'
+
+    async def to_gateway_request(self, payload: VoiceTranscript) -> GatewayRequest:
+        session_id = payload.session_id or payload.call_id
+        message_id = payload.message_id or (f'{payload.call_id}-turn-1' if payload.call_id else None)
+        bc = BusinessContext(
+            customer_key=payload.customer_key or payload.caller,
+            contract_key=payload.contract_key,
+            interaction_key=payload.interaction_key or payload.call_id,
+            session_key=session_id,
+            metadata={
+                'source_channel': 'voice',
+                'confidence': payload.confidence,
+                'language': payload.language,
+                **(payload.metadata or {}),
+            },
+        )
+        data = {
+            'message': payload.transcript,
+            'session_id': session_id,
+            'user_id': payload.caller,
+            'message_id': message_id,
+            'customer_key': bc.customer_key,
+            'contract_key': bc.contract_key,
+            'interaction_key': bc.interaction_key,
+            'session_key': bc.session_key,
+            'business_context': bc.model_dump(exclude_none=True),
+            'metadata': {
+                **(payload.metadata or {}),
+                'external_gateway': settings.APP_NAME,
+                'source_channel': 'voice',
+                'call_id': payload.call_id,
+                'confidence': payload.confidence,
+                'language': payload.language,
+                'contract_version': 'gateway-request-v1',
+            },
+        }
+        return GatewayRequest(channel='voice', tenant_id=settings.DEFAULT_TENANT_ID, agent_id=settings.DEFAULT_AGENT_ID, payload=data)

apps/channel_gateway/app/adapters/web.py

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+from __future__ import annotations
+
+from app.schemas import BusinessContext, GatewayRequest, WebMessage
+from app.settings import settings
+
+
+class WebAdapter:
+    name = 'web'
+
+    async def to_gateway_request(self, payload: WebMessage) -> GatewayRequest:
+        bc = payload.business_context or BusinessContext(
+            customer_key=payload.customer_key,
+            contract_key=payload.contract_key,
+            interaction_key=payload.interaction_key,
+            account_key=payload.account_key,
+            resource_key=payload.resource_key,
+            session_key=payload.session_key or payload.session_id,
+            metadata={'source_channel': 'web', **(payload.metadata or {})},
+        )
+        data = payload.model_dump(exclude_none=True)
+        data['business_context'] = bc.model_dump(exclude_none=True)
+        data.setdefault('session_key', payload.session_key or payload.session_id)
+        data.setdefault('metadata', {})
+        data['metadata'] = {
+            **(data.get('metadata') or {}),
+            'external_gateway': settings.APP_NAME,
+            'source_channel': 'web',
+            'contract_version': 'gateway-request-v1',
+        }
+        return GatewayRequest(
+            channel='web',
+            tenant_id=settings.DEFAULT_TENANT_ID,
+            agent_id=settings.DEFAULT_AGENT_ID,
+            payload=data,
+        )

apps/channel_gateway/app/adapters/whatsapp.py

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+from __future__ import annotations
+
+from app.schemas import BusinessContext, GatewayRequest, WhatsAppWebhook
+from app.settings import settings
+
+
+class WhatsAppAdapter:
+    name = 'whatsapp'
+
+    async def to_gateway_request(self, payload: WhatsAppWebhook) -> GatewayRequest:
+        user_id = payload.wa_id or payload.from_
+        text = payload.message or payload.text or payload.interactive_title or payload.interactive_id
+        if not text:
+            raise ValueError('INVALID_WHATSAPP_PAYLOAD: message/text/interactive_title is required')
+        session_id = payload.session_id or user_id
+        message_id = payload.message_id or payload.interaction_key
+        bc = BusinessContext(
+            customer_key=payload.customer_key or user_id,
+            contract_key=payload.contract_key,
+            interaction_key=payload.interaction_key or message_id,
+            session_key=session_id,
+            metadata={'source_channel': 'whatsapp', **(payload.metadata or {})},
+        )
+        data = {
+            'message': text,
+            'session_id': session_id,
+            'user_id': user_id,
+            'message_id': message_id,
+            'customer_key': bc.customer_key,
+            'contract_key': bc.contract_key,
+            'interaction_key': bc.interaction_key,
+            'session_key': bc.session_key,
+            'business_context': bc.model_dump(exclude_none=True),
+            'metadata': {
+                **(payload.metadata or {}),
+                'external_gateway': settings.APP_NAME,
+                'source_channel': 'whatsapp',
+                'interactive_id': payload.interactive_id,
+                'contract_version': 'gateway-request-v1',
+            },
+        }
+        return GatewayRequest(channel='whatsapp', tenant_id=settings.DEFAULT_TENANT_ID, agent_id=settings.DEFAULT_AGENT_ID, payload=data)

apps/channel_gateway/app/client.py

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+from __future__ import annotations
+
+import httpx
+from .settings import settings
+from .schemas import GatewayRequest
+
+
+class AgentFrameworkClient:
+    def __init__(self):
+        self.url = settings.AGENT_FRAMEWORK_BASE_URL.rstrip('/') + settings.AGENT_FRAMEWORK_GATEWAY_PATH
+
+    async def send(self, request: GatewayRequest) -> dict:
+        headers = {'Content-Type': 'application/json'}
+        if settings.INTERNAL_GATEWAY_TOKEN:
+            headers['X-Channel-Gateway-Token'] = settings.INTERNAL_GATEWAY_TOKEN
+        async with httpx.AsyncClient(timeout=settings.REQUEST_TIMEOUT_SECONDS) as client:
+            resp = await client.post(self.url, json=request.model_dump(exclude_none=True), headers=headers)
+            try:
+                data = resp.json()
+            except Exception:
+                data = {'text': resp.text}
+            if resp.status_code >= 400:
+                return {
+                    'ok': False,
+                    'status_code': resp.status_code,
+                    'error': data,
+                    'forwarded_to': self.url,
+                }
+            if isinstance(data, dict):
+                data.setdefault('ok', True)
+                data.setdefault('forwarded_to', self.url)
+                return data
+            return {'ok': True, 'data': data, 'forwarded_to': self.url}

apps/channel_gateway/app/main.py

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+from __future__ import annotations
+
+import logging
+from uuid import uuid4
+
+from fastapi import FastAPI, HTTPException, Request
+from fastapi.middleware.cors import CORSMiddleware
+
+from app.adapters.web import WebAdapter
+from app.adapters.whatsapp import WhatsAppAdapter
+from app.adapters.voice import VoiceAdapter
+from app.client import AgentFrameworkClient
+from app.schemas import GatewayRequest, VoiceTranscript, WebMessage, WhatsAppWebhook
+from app.settings import settings
+
+logging.basicConfig(level=settings.LOG_LEVEL)
+logger = logging.getLogger('external_channel_gateway')
+
+app = FastAPI(title='External Channel Gateway')
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=[o.strip() for o in settings.CORS_ORIGINS.split(',')],
+    allow_credentials=True,
+    allow_methods=['*'],
+    allow_headers=['*'],
+)
+
+client = AgentFrameworkClient()
+web_adapter = WebAdapter()
+whatsapp_adapter = WhatsAppAdapter()
+voice_adapter = VoiceAdapter()
+
+
+def _require_mode(expected: str, endpoint_type: str):
+    if settings.runtime_mode != expected:
+        raise HTTPException(
+            status_code=409,
+            detail={
+                'error_code': 'CHANNEL_GATEWAY_MODE_MISMATCH',
+                'message': f'{endpoint_type} endpoints require CHANNEL_GATEWAY_RUNTIME_MODE={expected}',
+                'current_runtime_mode': settings.runtime_mode,
+            },
+        )
+
+
+async def _forward(request: GatewayRequest) -> dict:
+    return await client.send(request)
+
+
+@app.get('/health')
+async def health():
+    return {
+        'status': 'ok',
+        'app_name': settings.APP_NAME,
+        'runtime_mode': settings.runtime_mode,
+        'configured_runtime_mode': settings.CHANNEL_GATEWAY_RUNTIME_MODE,
+        'legacy_channel_gateway_mode': settings.CHANNEL_GATEWAY_MODE,
+        'backend_url': client.url,
+        'default_tenant_id': settings.DEFAULT_TENANT_ID,
+        'default_agent_id': settings.DEFAULT_AGENT_ID,
+    }
+
+
+@app.post('/channels/web/message')
+async def web_message(payload: WebMessage, request: Request):
+    _require_mode('adapter', '/channels/*')
+    gateway_request = await web_adapter.to_gateway_request(payload)
+    gateway_request.payload.setdefault('metadata', {})
+    gateway_request.payload['metadata'].update({
+        'channel_gateway_request_id': request.headers.get('x-request-id') or str(uuid4()),
+        'channel_gateway_endpoint': '/channels/web/message',
+    })
+    return await _forward(gateway_request)
+
+
+@app.post('/channels/whatsapp/webhook')
+async def whatsapp_webhook(payload: WhatsAppWebhook, request: Request):
+    _require_mode('adapter', '/channels/*')
+    try:
+        gateway_request = await whatsapp_adapter.to_gateway_request(payload)
+    except ValueError as exc:
+        raise HTTPException(status_code=422, detail=str(exc)) from exc
+    gateway_request.payload.setdefault('metadata', {})
+    gateway_request.payload['metadata'].update({
+        'channel_gateway_request_id': request.headers.get('x-request-id') or str(uuid4()),
+        'channel_gateway_endpoint': '/channels/whatsapp/webhook',
+    })
+    return await _forward(gateway_request)
+
+
+@app.post('/channels/voice/transcript')
+async def voice_transcript(payload: VoiceTranscript, request: Request):
+    _require_mode('adapter', '/channels/*')
+    gateway_request = await voice_adapter.to_gateway_request(payload)
+    gateway_request.payload.setdefault('metadata', {})
+    gateway_request.payload['metadata'].update({
+        'channel_gateway_request_id': request.headers.get('x-request-id') or str(uuid4()),
+        'channel_gateway_endpoint': '/channels/voice/transcript',
+    })
+    return await _forward(gateway_request)
+
+
+@app.post('/gateway/message')
+async def proxy_gateway_message(payload: GatewayRequest, request: Request):
+    _require_mode('proxy', '/gateway/message')
+    payload.payload.setdefault('metadata', {})
+    payload.payload['metadata'].update({
+        'channel_gateway_request_id': request.headers.get('x-request-id') or str(uuid4()),
+        'channel_gateway_endpoint': '/gateway/message',
+        'proxied_by': settings.APP_NAME,
+    })
+    return await _forward(payload)

apps/channel_gateway/app/schemas.py

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+from __future__ import annotations
+
+from typing import Any
+from pydantic import BaseModel, Field
+
+
+class BusinessContext(BaseModel):
+    customer_key: str | None = None
+    contract_key: str | None = None
+    interaction_key: str | None = None
+    account_key: str | None = None
+    resource_key: str | None = None
+    session_key: str | None = None
+    protocol_key: str | None = None
+    metadata: dict[str, Any] = Field(default_factory=dict)
+
+
+class WebMessage(BaseModel):
+    message: str
+    session_id: str | None = None
+    user_id: str | None = None
+    message_id: str | None = None
+    customer_key: str | None = None
+    contract_key: str | None = None
+    interaction_key: str | None = None
+    account_key: str | None = None
+    resource_key: str | None = None
+    session_key: str | None = None
+    business_context: BusinessContext | None = None
+    metadata: dict[str, Any] = Field(default_factory=dict)
+
+
+class WhatsAppWebhook(BaseModel):
+    wa_id: str | None = None
+    from_: str | None = Field(default=None, alias="from")
+    message: str | None = None
+    text: str | None = None
+    session_id: str | None = None
+    message_id: str | None = None
+    interactive_id: str | None = None
+    interactive_title: str | None = None
+    raw: dict[str, Any] = Field(default_factory=dict)
+    customer_key: str | None = None
+    contract_key: str | None = None
+    interaction_key: str | None = None
+    metadata: dict[str, Any] = Field(default_factory=dict)
+
+
+class VoiceTranscript(BaseModel):
+    transcript: str
+    call_id: str | None = None
+    caller: str | None = None
+    session_id: str | None = None
+    message_id: str | None = None
+    confidence: float | None = None
+    language: str | None = None
+    customer_key: str | None = None
+    contract_key: str | None = None
+    interaction_key: str | None = None
+    metadata: dict[str, Any] = Field(default_factory=dict)
+
+
+class GatewayRequest(BaseModel):
+    channel: str
+    payload: dict[str, Any]
+    agent_id: str | None = None
+    tenant_id: str | None = None
+
+
+class GatewayResponse(BaseModel):
+    channel: str | None = None
+    session_id: str | None = None
+    text: str | None = None
+    metadata: dict[str, Any] = Field(default_factory=dict)

apps/channel_gateway/app/settings.py

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+from __future__ import annotations
+
+from typing import Literal
+from dotenv import load_dotenv
+from pydantic_settings import BaseSettings, SettingsConfigDict
+
+load_dotenv(override=False)
+
+
+class Settings(BaseSettings):
+    model_config = SettingsConfigDict(env_file='.env', env_file_encoding='utf-8', extra='ignore')
+
+    APP_NAME: str = 'external-channel-gateway'
+    LOG_LEVEL: str = 'INFO'
+    API_HOST: str = '0.0.0.0'
+    API_PORT: int = 7000
+    CORS_ORIGINS: str = 'http://localhost:5173,http://127.0.0.1:5173'
+
+    # adapter = receive native/simple channel payloads and translate them to GatewayRequest.
+    # proxy   = receive only GatewayRequest and forward it after validation.
+    CHANNEL_GATEWAY_RUNTIME_MODE: Literal['adapter','proxy'] = 'adapter'
+    # Legacy alias accepted only for compatibility. Prefer CHANNEL_GATEWAY_RUNTIME_MODE.
+    CHANNEL_GATEWAY_MODE: str | None = None
+
+    AGENT_FRAMEWORK_BASE_URL: str = 'http://localhost:8000'
+    AGENT_FRAMEWORK_GATEWAY_PATH: str = '/gateway/message'
+    DEFAULT_TENANT_ID: str = 'default'
+    DEFAULT_AGENT_ID: str = 'telecom_contas'
+    REQUEST_TIMEOUT_SECONDS: float = 120.0
+
+    INTERNAL_GATEWAY_TOKEN: str | None = None
+
+    @property
+    def runtime_mode(self) -> str:
+        legacy = (self.CHANNEL_GATEWAY_MODE or '').strip().lower()
+        if legacy in {'adapter', 'proxy'}:
+            return legacy
+        # Legacy mapping for old deployments: embedded meant adapters on.
+        if legacy == 'embedded':
+            return 'adapter'
+        if legacy == 'external':
+            return 'proxy'
+        return self.CHANNEL_GATEWAY_RUNTIME_MODE
+
+
+settings = Settings()