Spatial9 open source spatial audio pipeline

A complete spatial audio pipeline from open source tools only, reaching Spatial9 over MCP and A2A, with real-time webhooks, Server-Sent Events and a live preview page.

Spatial9 open source pipeline

A complete spatial audio pipeline built only from open source tools, with Spatial9 reached over open protocols (MCP and A2A over HTTPS). Drop a WAV into a bucket and, a few minutes later, a browser page plays the binaural version while Eclipsa Audio (IAMF) and an MP4 land in storage.

Read the full guide: https://spatial9.ai/blog/open-source-spatial-audio-pipeline-real-time-spatial9

 WAV into MinIO ──event──▶ Kafka (audio.uploaded) ──▶ worker.py
                                                        │  FFmpeg check + loudness
                                                        │  MCP create_upload_link + PUT
                                                        │  A2A message/send (spatial_audio)
                                                        ▼
                                            Spatial9 agent (spatial9.ai/a2a)
                                                        │ push on every state change
                                                        ▼
 browser ◀── SSE /events ◀── Valkey pub/sub ◀── webhook.py ──▶ MinIO immersive bucket
                                                        └──▶ PostgreSQL tracks + track_events
 Prometheus ◀── /metrics (worker, webhook) ──▶ Grafana
 Dagster (dagster_catalog.py): nightly backfill of old masters + daily report

Files

File · What it does

docker-compose.yml · MinIO, Apache Kafka, PostgreSQL, Valkey, worker, webhook, Prometheus and Grafana

env.example · Every setting; copy to .env

schema.sql · tracks and the append-only track_events

worker.py · Kafka consumer, FFmpeg checks, slot control, MCP upload, A2A task, fallback polling

webhook.py · FastAPI: verified A2A push notifications, MinIO copies, Server-Sent Events, metrics

preview.html · Live status page that plays the binaural result

dagster_catalog.py · Nightly backfill and report assets

prometheus.yml · Scrapes the worker and webhook

The worker imports the shared clients in ../shared (spatial9_mcp.py, spatial9_a2a.py).

Run it

1. Create a key at https://spatial9.ai/connect, then cp env.example .env and fill it in.
2. Make the webhook reachable over https (reverse proxy or tunnel) and put that address in PUBLIC_WEBHOOK_URL.
3. docker compose up -d
4. Create the bucket and the event rule with the MinIO client:

```bash

mc alias set local http://localhost:9000 "$MINIO_ROOT_USER" "$MINIO_ROOT_PASSWORD"

mc mb local/masters

mc event add local/masters arn:minio:sqs::PRIMARY:kafka --event put

```

1. mc cp my-song.wav local/masters/ and open http://localhost:8080, then follow my-song.

Limits and safety

• 3 renders at once and 20 per day per key; free_slots() enforces both before anything starts. Failed renders are refunded.
• messageId is oss-spatial_audio-<track>-v<version>, so a retry never starts a second render.
• Pushes are accepted only with the right X-A2A-Notification-Token (constant-time check), and the task is re-read with tasks/get.
• Keys live only in .env; never commit it.

Licences change (MinIO, Grafana and Redis have all changed terms in recent years). Check each project before production use. MIT licence for these examples.

Files

• solutions/open-source/dagster_catalog.py
• solutions/open-source/docker-compose.yml
• solutions/open-source/env.example
• solutions/open-source/preview.html
• solutions/open-source/prometheus.yml
• solutions/open-source/README.md
• solutions/open-source/requirements.txt
• solutions/open-source/schema.sql
• solutions/open-source/webhook.py
• solutions/open-source/worker.py

Read the open source pipeline guide