Week 34 · 2026

Highlights

8 PRs merged, 5 opened and 47 commits, with no issue activity. Only 4 of the 13 items carry a milestone this week, but those four include the headline: the CBOR pair, in review since mid-July, landed under Performance.

Reactive. Four merges, all cleanup. The library re-use PR from W33 (#2825) replaced the hand-rolled metrics registry with the Prometheus library, fixing a latent bug where mistyped metric lookups silently did nothing; corrected the published cost table's minimum-fee estimate, which was missing Conway's reference-script charge and under-reporting by roughly 30%; made a truncated etcd revision file fail loudly instead of silently rewinding the watch; and cut the tx-cost-diff Nix closure by 90% (719 MiB to 67 MiB). Alongside it: dead code removal, also from W33 (#2823), weeder fixups on top of it (#2832), and dead-link fixes on the docs site (#2834). Of the five PRs opened, three target known issues: Blockfrost query caching (#2835) goes after the per-block TimeHandle rebuild that accounts for roughly 75% of steady-state Blockfrost API usage (#2833); script integrity fixes (#2836) unblock the reference-script commit pattern, where coverFee_ wrote a script-integrity hash for scripts that never execute and the ledger rejected the tx (#2594); and strict value UTxO (#2837) forces L2 UTxO values at construction (#2831), the lazy thunks behind a 1.42s snapshot force that blew the close validity window on the plateau-1k bench. The other two, flakiness fixes (#2838) and spec-font trimming plus faster-clone docs, 36M to 11M of fonts, 108s to 18s clones (#2839), both merged Monday morning.

Maintenance and DevX (M5). The fuel/funds naming unification merged (#2800), a breaking change: hydra-tui's ambiguous --cardano-signing-key becomes --funds-signing-key, the demo's tmux panes now hand the TUI the funds keys instead of the node's fuel key, and the docs explain the fuel vs funds distinction where the keys are introduced. hydra-node's own key options are deliberately unchanged, since that key is the participant's L1 identity, not just fuel.

Operational Excellence (M3). A test that partial fanout recovers funds when an unburned token is present (#2793), extending coverage of the selective partial fanout from W30.

Performance (M2). The CBOR pair merged. CBOR-1 (#2767) switches persisted event payloads from JSON to CBOR: a real 3-node bench database shrinks 2.6x (27.4 MB to 10.5 MB), with an automatic migration that rolls back to an intact v1 database if any row fails to decode; breaking, with no downgrade path. CBOR-2 (#2762) adds opt-in binary CBOR to the client API (?encoding=cbor on WebSocket, content negotiation on HTTP): wire sizes drop 2.2-3.1x and encode/decode is 3-21x faster, client decode of a 1000-UTxO snapshot going from 46.8 ms to 3.2 ms. It also reworks the snapshot-utxo=no filter to apply before serialization, taking filtered sends from 26 ms to about 10 us. JSON stays the default, byte-for-byte unchanged, and golden tests now pin the on-disk format in CI.

KPI & Outcome Achievement (M6). Tracker improvements: weekly notes now auto-link issue and PR references.