onionoo-fastapi

FastAPI-based semantic/OpenAPI proxy for the Tor Onionoo API.

• GitHub: https://github.com/anoni-net/onionoo-fastapi
• Upstream data source: https://onionoo.torproject.org
• This service does not store Onionoo data, it only forwards requests and transforms responses.
• Primary motivation: Onionoo has a solid spec, but no OpenAPI; this service provides a friendly schema for tooling/AI agents.

Reference spec: Tor Metrics – Onionoo

Hosted instance

• Service: https://onionoo.anoni.net
• Swagger UI: https://onionoo.anoni.net/docs

License

MIT. See LICENSE.

Requirements

• Python 3.11+
• uv

Install

git clone https://github.com/anoni-net/onionoo-fastapi
cd onionoo-fastapi
uv sync

Or if you already have the source:

cd onionoo-fastapi
uv sync

Run

fastapi run app.main:app --reload --host 0.0.0.0 --port 8000

Note: fastapi run requires FastAPI version 0.110.0 or newer.

OpenAPI docs:

• Swagger UI: http://localhost:8000/docs
• OpenAPI JSON: http://localhost:8000/openapi.json

Docker

Build and run with Docker Compose:

docker compose up -d --build

If port 8000 is already in use, override host port (example: 8001):

HOST_PORT=8001 docker compose up -d --build

Stop:

docker compose down

Configuration via environment variables (example):

ONIONOO_BASE_URL=https://onionoo.torproject.org HOST_PORT=8001 docker compose up -d --build

API

This service exposes semantic endpoints under /v1/*:

• GET /v1/summary
• GET /v1/details
• GET /v1/bandwidth
• GET /v1/weights
• GET /v1/clients
• GET /v1/uptime

Plus:

• GET /healthz

Example requests

# Summary (semantic keys; upstream short keys are transformed)
curl -s 'http://localhost:8000/v1/summary?limit=1' | jq .

# Details (supports Onionoo query parameters + details-only `fields`)
curl -s 'http://localhost:8000/v1/details?limit=1&search=moria&fields=nickname,fingerprint' | jq .

# Bandwidth
curl -s 'http://localhost:8000/v1/bandwidth?limit=1&search=moria' | jq .

# Weights (relays only)
curl -s 'http://localhost:8000/v1/weights?limit=1&search=moria' | jq .

# Clients (bridges only)
curl -s 'http://localhost:8000/v1/clients?limit=1' | jq .

# Uptime
curl -s 'http://localhost:8000/v1/uptime?limit=1&search=moria' | jq .

Semantic field mapping notes

• /v1/summary transforms Onionoo short keys:
  • relay: n,f,a,r → nickname,fingerprint,addresses,running
  • bridge: n,h,r → nickname,hashed_fingerprint,running
• For some bridge documents (/bandwidth, /clients, /uptime), Onionoo uses the key name fingerprint even though the value is a hashed fingerprint; this API exposes that as hashed_fingerprint.

Caching / 304 behavior

If the client includes If-Modified-Since, it will be forwarded upstream. If Onionoo replies with 304, this service will reply 304 too.

Configuration

• ONIONOO_BASE_URL (default: https://onionoo.torproject.org)