> ## Documentation Index
> Fetch the complete documentation index at: https://docs.useharmonia.xyz/llms.txt
> Use this file to discover all available pages before exploring further.

# Platform and infrastructure

> Technology map for Harmonia's UI, agent runtime, durable state, integrations, media pipeline, and observability.

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                                      |

<Warning>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.</Warning>

## 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