Installation

Prerequisites

Go 1.22 or later (check your own go.mod's go directive if installing from source — this must match or exceed it)
PostgreSQL 13 or later (the engine's migration uses gen_random_uuid(), built into Postgres core since version 13)
A Postgres connection string (self-hosted, or a managed provider such as Supabase, Neon, or RDS)

Installing the engine (for Go developers embedding it directly)

go get github.com/crydensync/cryden/v2

Note the /v2 in the import path — this is required by Go's module system for any major version 2 or above, not optional or cosmetic.

Running the database migration

The engine's schema (users, sessions, audit_events, verification_tokens tables) is defined in store/postgres/migrations/0001_initial_schema.up.sql within the cryden repository. Apply it directly:

psql "$DATABASE_URL" -f store/postgres/migrations/0001_initial_schema.up.sql

A corresponding .down.sql file exists for rollback.

Installing the HTTP API (for non-Go developers, or Go developers wanting a REST interface)

git clone https://github.com/crydensync/api
cd api
cp .env.example .env
# fill in DATABASE_URL, JWT_SECRET, CORS_ORIGINS
go run .

The api repository includes its own copy of the engine's migration under migrations/, so it can be set up without also cloning the cryden repository separately.

Installing the admin CLI

go install github.com/crydensync/csax@latest
csax config init

config init interactively prompts for your database connection string and JWT secret, writing them to a local .env file.

Installing the JavaScript/TypeScript SDK

npm install @crydensync/sdk

Requires a running api instance to connect to — the SDK does not talk to Postgres or the Go engine directly, only to the HTTP API.

Connecting to Supabase specifically

Supabase provides three connection string variants. For CrydenSync:

Use: the direct connection string, or the session pooler — both support the multi-statement database transactions the engine relies on for atomic refresh token rotation.
Avoid: the transaction pooler (commonly on port 6543) — pgbouncer running in transaction mode can interfere with the multi-statement transactions the engine's RotateToken operation depends on.
If your network lacks IPv6 connectivity (common on some mobile carriers and certain home networks), the direct connection string (which typically resolves to an IPv6-only address on Supabase) will fail with a "network unreachable" error even with fully correct credentials. The session pooler connection string resolves over IPv4 and avoids this.

A known platform-specific issue: Android/Termux

Go's standard library has os/user.Current() explicitly unimplemented for GOOS=android. The lib/pq Postgres driver (used by the engine's Postgres implementation) calls this internally during connection setup, which causes every database connection attempt to fail on Android/Termux with an error resembling pqutil.User: not supported on current platform — regardless of how correct the connection string and credentials are. No environment variable resolves this, because the underlying code path does not exist for that platform at compile time.

Workarounds:

Run inside a proper Linux userland on the device (e.g. via proot-distro install ubuntu), where a GOOS=linux Go toolchain behaves normally.
Use a real Linux or macOS machine instead.

This is not specific to any one CrydenSync repository — it affects any Go program using lib/pq on Android.

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