EFB Connector
A multi-tenant web service that automatically syncs water sport activities from Garmin Connect to the Kanu-EFB electronic logbook.
Live instance: efb-connector.sauroter.de
Features
- Automatic daily sync — paddling activities are synced from Garmin Connect to Kanu-EFB every day at ~04:00 UTC
- Trip logbook entries — automatically create Fahrten (logbook entries) in EFB from synced tracks with pre-filled start/end times
- River data enrichment — trip entries enriched with river section name, difficulty grade, and gauge readings via Rivermap
- Manual sync & history — trigger syncs on demand, sync custom date ranges, and review a full sync log with detailed status
- Passwordless authentication — sign in with a magic link sent to your email
- Garmin MFA support (beta) — two-factor authentication on Garmin? Enter your verification code during setup
- Encrypted credential storage — Garmin and EFB credentials encrypted at rest with AES-256-GCM
- Guided onboarding — 4-step setup wizard walks new users through connecting accounts and configuring preferences
- Self-service management — connect/disconnect accounts, manage preferences, view history, delete your data
Supported Activity Types
- Kayaking
- Stand Up Paddleboarding (SUP)
- Canoeing
- Rowing
- Paddling
- Whitewater Rafting
How It Works
- Sign in with your email — a magic link is sent, no password needed
- Connect your Garmin Connect and Kanu-EFB accounts (credentials are validated and stored encrypted)
- Configure your preferences — auto-create trip entries, enrich with river data
- Relax — your activities sync automatically every day, or trigger a manual sync anytime
Getting Started
Prerequisites
- Go 1.27+
- Python 3.14+ with
garminconnect package
- GNU Make (included in devbox)
Or use devbox to get everything automatically:
devbox shell
Local development
The fastest way to run the server locally uses dev mode, which substitutes mock implementations for Garmin Connect and Kanu-EFB so no external accounts are needed:
make dev
This starts the server on http://localhost:8080 with mock providers. Magic link emails are printed to stdout instead of being sent.
Build
make build
Run tests
make test
All Make targets
| Target | Description |
|---|
make dev | Run server in dev mode (mock EFB + Garmin, auto-generated encryption key) |
make build | Build the efb-connector binary |
make test | Run all tests (unit + integration) |
make cover | Run tests with coverage and print per-function summary |
make lint | Run golangci-lint (install via make lint-install) |
make lint-install | Install the pinned golangci-lint version into $GOPATH/bin |
make clean | Remove built binaries and local dev database |
Running with real providers
ENCRYPTION_KEY=<base64-encoded-32-byte-key> \
RESEND_API_KEY=<resend-api-key> \
INTERNAL_SECRET=<secret> \
BASE_URL=http://localhost:8080 \
go run ./cmd/server
Configuration
The server is configured via environment variables:
| Variable | Description |
|---|
ENCRYPTION_KEY | Base64-encoded 32-byte key for credential encryption |
RESEND_API_KEY | Resend API key for sending magic link emails |
INTERNAL_SECRET | Secret for internal/cron API endpoints |
BASE_URL | Public base URL (e.g. https://efb-connector.sauroter.de) |
PORT | HTTP listen port (default: 8080) |
DB_PATH | Path to SQLite database file (default: efb-connector.db) |
DEV_MODE | Set to true for local dev (mock EFB + Garmin, relaxed env requirements) |
Deployment
The service is deployed on Fly.io in the Frankfurt (fra) region with a persistent volume for the SQLite database.
fly deploy
See infrastructure/README.md for detailed deployment and operations instructions.
EFB egress IP rotation
EFB rate-limits the source IP of our login requests. We keep a static Fly egress IPv6 allocated so it can be whitelisted by the EFB maintainers. The nightly bulk run paces at ~30s/user, so a healthy run is roughly 60–80 min; runs that approach the 120-min cap indicate the absorbed-rate-limit-backoff path tripped. If the nightly sync fails with efb login rate-limited, rotate to a fresh egress IP and notify Tim (kanu-efb.de) of the new address:
make egress-status # show current allocations + live outbound IPv6
make rotate-egress # allocate new pair, restart machine, release old pair
API Documentation
The full REST API (public, authenticated, and internal endpoints) is documented in openapi.yaml using the OpenAPI 3.1 specification. You can view it with any OpenAPI-compatible tool (Swagger UI, Redoc, etc.).
Legal
License
Licensed under the Apache License, Version 2.0. See LICENSE for the full text.
