Platform and infrastructure - Harmonia

Harmonia separates agentic judgment from deterministic workflow authority. Models analyze, plan, write, review, compose bounded interfaces, and answer read-only questions. Application services own state transitions, approvals, external effects, receipts, and verification.

How Harmonia uses it

Area	Components	Responsibility
UI	Next.js, React, Google A2UI	Dashboard, chat, authenticated APIs, and server-hydrated generative surfaces
Agents and AI	Google ADK, Gemini, Vertex AI Agent Engine, Memory Bank	Bounded specialist reasoning and eligible advisory memory
Security and identity	Firebase Authentication, IAM service accounts, Secret Manager	Operator identity, machine identity, and server-side credentials
Storage and messaging	Firestore, Pub/Sub, Cloud Storage	Durable workflow truth, asynchronous stage delivery, and binary assets
Runtime and automation	Cloud Run, Cloud Scheduler	Web/worker hosting and authenticated durable ticks
Media	ffmpeg, Vertex generative media	Deterministic rendering and approval-gated generated assets
Integrations	X API, Telegram Bot API, Google Calendar API, Hacker News Algolia, YouTube	Publishing, operator access, explicit calendar synchronization, public signals, and authorized sources
Observability	OpenTelemetry, Cloud Trace target, structured logs, metrics, budget records	Correlation, diagnosis, usage accounting, and operator visibility

Firestore is the durable workflow authority. Agent Engine sessions, Memory Bank facts, model output, telemetry, and external API responses cannot approve or authorize an effect.

Evidence status

Repository tests and local emulator runs establish contract behavior. A technology page labels authenticated cloud or provider evidence separately. Code presence, mock mode, or a deploy script is not proof that a managed service or external effect has run successfully.

Source map

src/ — Next.js UI, APIs, state, integrations, and telemetry
agent/harmonia_agent/ — ADK team, worker stages, media, memory, and provider clients
infra/ — Google Cloud setup and deployment scripts
docs/ — operational contracts and evidence runbooks

Last modified on August 26, 2026