Changelog

All notable changes to Hail are documented here. The format is based on Keep a Changelog, and Hail adheres to Semantic Versioning.

0.1.0 — 2026-04-30

First public release. Outbound phone calls for AI agents, end-to-end.

Phone calls

• Outbound calls via Twilio SIP through LiveKit Cloud.
• POST /calls, GET /calls/{id}, and GET /calls with cursor pagination.
• Per-org API-key auth with audit logging on every authenticated request.
• Idempotency-Key support on POST /calls (24h TTL).

Voice pipeline

• Deepgram STT.
• ElevenLabs TTS.
• Silero VAD (prewarmed once per worker process).
• LiveKit turn-detector for end-of-utterance detection.
• LLM system-prompt mode with OpenAI to Gemini to Anthropic fallback chain.
• LLM BYO-endpoint mode for any OpenAI chat-completions-compatible endpoint.
• Per-turn call_events rows for transcript reconstruction.

Distribution

• OpenAPI 3.1 spec at openapi/openapi.yaml as the source of truth.
• hail CLI binary published via GitHub Releases (darwin and linux, amd64 and arm64) and a Homebrew tap.
• Remote MCP server bundled with every Hail deploy at /sse, exposing a place_call tool.
• hail-sdk on PyPI (imports as hail) with Client.calls.create / get / list.

Infrastructure

• docker compose up brings up api, voicebot, mcp, and Postgres.
• Alembic migrations for the v1 schema.
• CI runs lint, pytest with a Postgres service container, Go build and test, and a docker-compose build smoke.

Deferred to v1.x

• LiveKit Egress recording (recording.py is stubbed; Call.recording_s3_key is always NULL).
• idempotency_keys GC sweeper and in-flight reaper.
• Inbound calls (LIVEKIT_SIP_INBOUND_TRUNK_ID is reserved in env but unused).
• SMS channel (Twilio outbound and inbound).
• Email channel (AWS SES outbound and inbound).
• CallEvent dedupe across voicebot redispatch.