GK.Gergely Kovács
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trut.hu

ActiveDAO · Sustainability2024 — 2026
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Sustainability-DAO backend with governance, TTS and AI agents.

FastAPI + SQLAlchemy + Alembic backend with multi-tenant governance and AI-agent flows. 94 personal commits, mypy / ruff / pre-commit hardened, fully containerised with docker-compose.

Stack
PythonFastAPISQLAlchemyPostgreSQLPydanticDockerLinux
Architecture

How it's built

An async FastAPI app over SQLAlchemy + Alembic with a Celery fleet of 20 prefork workers and a RedBeat scheduler for the governance heartbeats. Supabase handles JWT auth and tier checks; OpenRouter routes LLM calls; ElevenLabs renders audio summaries; and N8N picks up the rest over a shared volume. Multi-tenant isolation lives at the DB row level so a DAO never sees another DAO's data even through buggy app code.

Data flow
  1. 01Client request hits FastAPI — Supabase JWT is verified and the caller's subscription tier is read in the same hop.
  2. 02Allowed requests are persisted to Postgres with the tenant id stamped on every row; rate-limit counters tick in Redis DB 3.
  3. 03Governance tasks are enqueued to the broker DB; RedBeat fires scheduled DAO digests on its own cadence.
  4. 04A worker fetches the relevant feeds, calls OpenRouter for summarisation, then ElevenLabs for the audio rendering.
  5. 05Final audio is written to /n8n/files/{lang}/final_mix.mp3 — N8N picks it up and runs the publish workflow.
  6. 06Audit trail (who, when, which model) is committed to Postgres; the result is cached in Redis and returned to the user.
Design decisions
  • Four Redis DBs separated by purpose — broker, results, RedBeat schedule, rate-limit counters — so noisy neighbours stay in their lane.
  • RedBeat over Celery's default PersistentScheduler — survives Beat restarts, picks up new schedule rows live without a redeploy.
  • Workers cap at 50 tasks per child to bound memory leaks from long LLM contexts; prefork pool keeps the GIL out of the Pandas math.
  • N8N receives finished audio via a shared volume rather than HTTP — file paths are the contract, no marshalling overhead.
  • pre-commit hardening: mypy, ruff, black gate every commit so the multi-tenant boundary checks cannot rot.
External integrations
Supabase (JWT + subscription tier)OpenRouter (LLM gateway)ElevenLabs (TTS)N8N (workflow handoff)Postgres 16Redis (4 logical DBs)Flower
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