Cache trees

Exact-replay inventory can be scoped per preview or agent run — without branching a database.

Default traffic uses the main tree (unchanged cache keys). Set X-Ohm-Cache-Tree (or body cache_tree) to isolate HITs for a PR or run. Fork, promote, freeze, and reset are available on /v1/cache/trees.

Tips isolate exact-replay inventory per PR or agent run. For pairing tips with a database preview branch in CI, see Compose with Neon.

Metrecept cache trees

Dashed = preview tip (ephemeral)
Hatch = main (durable)
Silver = Promote crossing

Metrecept branches exact-replay inventory by tip. For pairing tips with a database preview branch in CI, see Compose with Neon.

Select a tree

curl -s https://api.withohm.dev/v1/chat/completions \
  -H "Authorization: Bearer sk-at-YOUR_OHM_KEY" \
  -H "X-Ohm-Cache-Tree: pr-842" \
  -H "Content-Type: application/json" \
  -d '{"model":"mock","messages":[{"role":"user","content":"hi"}]}'

Invalid names return 400. Frozen trees reject new writes (409) but can still serve HITs.

COW reads may serve a parent blob without copying into the child tip. That is not yet a single shared content-addressed store with many refs — Promote still copies child-local digests.

Fork, promote, freeze

Promote copies digests written on the child into the parent index (COW reads mean the child could already HIT parent warm entries without copying).

# Fork from main
curl -s https://api.withohm.dev/v1/cache/trees \
  -H "Authorization: Bearer sk-at-YOUR_OHM_KEY" \
  -H "Content-Type: application/json" \
  -d '{"name":"pr-842"}'

# After warming the preview tree, merge new digests into main
curl -s https://api.withohm.dev/v1/cache/trees/pr-842/promote \
  -H "Authorization: Bearer sk-at-YOUR_OHM_KEY" \
  -H "Content-Type: application/json" \
  -d '{}'

# Freeze a finished CI artifact
curl -s https://api.withohm.dev/v1/cache/trees/pr-842/freeze \
  -H "Authorization: Bearer sk-at-YOUR_OHM_KEY" \
  -X POST