Knowledge Base Index — Haygen

Reference knowledge for the Haygen project.

SDK & Platform

• 01-heygen-sdk-api — HeyGen streaming avatar SDK API reference, event types, token endpoint, credit pricing

Architecture Decisions

• ADR-001-two-phase-sdk-init — Why SDK is created synchronously before first await
• ADR-002-cli-entry-direct — Why CLI tsup entry is direct (sideEffects:false gotcha)
• ADR-003-lite-mode-accumulation — Why USER_TALKING_MESSAGE is accumulated (USER_END_MESSAGE has no message)
• ADR-004-vitest-inline-deps — Why @heygen/streaming-avatar must be inlined in vitest

Specs & Plans

• Implementation plan: /Users/arijitchowdhury/AI-Development/Haygen/.worktrees/feature-heygen-avatar-package/docs/superpowers/plans/2026-05-04-heygen-avatar-package.md
• PRD: /Users/arijitchowdhury/AI-Development/Haygen/.worktrees/feature-heygen-avatar-package/docs/requirements/PRD-heygen-avatar-package.md

External References

• HeyGen persona best practices: https://help.heygen.com/en/articles/9585924
• HeyGen streaming avatar SDK: https://github.com/HeyGen-Official/StreamingAvatarSDK
• npm package: https://github.com/arijitchowdhury80/heygen-avatar