Elevenlabs Twilio Memory Bridge

FastAPI personalization webhook that adds persistent caller memory and dynamic context injection to ElevenLabs Conversational AI agents on Twilio. No audio proxying, file-based persistence, OpenClaw compatible.

Personalization webhook service for ElevenLabs + Twilio voice agents with persistent caller memory.

What It Does

When a call arrives on your Twilio number, ElevenLabs' native integration triggers this webhook. The bridge looks up the caller's history, loads long-term memory facts and daily context notes, combines them with a customizable soul/personality template, and returns everything as a system prompt override so your agent greets each caller with full context.

Architecture

• No audio proxying — ElevenLabs and Twilio handle media directly
• Webhook only — called once per inbound call to inject context
• File-based persistence — JSON files in ./data/, zero external dependencies
• OpenClaw compatible — works with any OpenAI-compatible LLM endpoint

Endpoints

Endpoint	Method	Purpose
/webhook/personalize	POST	ElevenLabs calls this on inbound call
/webhook/post-call	POST	Optional post-call cleanup
/api/memory/{phone_hash}	POST	Add long-term fact about a caller
/api/notes	POST	Add global or caller-scoped context note
/health	GET	Health check

Setup

1. Clone repo, pip install -r requirements.txt
2. Copy .env.example to .env, fill in secrets
3. Configure ElevenLabs agent with Custom LLM pointing to your OpenClaw instance
4. Enable system prompt + first message overrides in agent Security settings
5. Add webhook URL https://your-domain/webhook/personalize in ElevenLabs settings
6. Import Twilio number in ElevenLabs dashboard
7. Run: uvicorn app:app --host 0.0.0.0 --port 8000

Required Environment Variables

• ELEVENLABS_API_KEY — scoped ElevenLabs key
• ELEVENLABS_AGENT_ID — your agent ID
• OPENCLAW_API_BASE_URL — your OpenClaw instance URL
• PUBLIC_BASE_URL — publicly reachable URL of this service
• ADMIN_API_KEY — secret for admin endpoint auth

Optional Environment Variables

Variable	Default	Purpose
WEBHOOK_SECRET	(unset)	Shared secret for HMAC webhook verification
SOUL_TEMPLATE_PATH	./soul_template.md	Path to personality template file
DATA_DIR	./data	Directory for JSON persistence
ALLOWED_ORIGINS	(unset)	Comma-separated CORS origins
HOST	0.0.0.0	Bind address for uvicorn
PORT	8000	Listen port
LOG_LEVEL	INFO	Python logging level

Security

• All caller phone numbers are SHA-256 hashed before storage/logging
• Secrets loaded exclusively from environment variables
• Optional HMAC webhook signature verification
• Safe for public GitHub repos, no secrets in source