Building an adapter

An adapter wraps one backend and declares exactly what it can do.

Contract expectations

• Implement DurableAdapter, EphemeralAdapter, or both.
• Declare truthful capabilities (git, pr, ttl, etc.).
• Return stable Ref serialization.
• Fail with typed GitTrix errors where possible.

Capability declaration

const capabilities = {
  git: true,
  push: true,
  fetch: true,
  history: true,
  pr: false,
  ttl: false,
  latencyClass: 'regional',
}

Bad capability declarations create bad routing decisions. Keep them strict.

Testing patterns

• Contract tests for every adapter method.
• Capability-gated behavior tests (e.g., PR strategy fails if pr: false).
• Baseline conflict tests around promotion.
• TTL/eviction tests for adapters with native expiration.

Build against real backend semantics, not mock-only behavior.