Adaptive MIDI buffering

How far up the trust ladder

Each rung is a claim that has actually been checked, and they are climbed in order — a later check passing while an earlier one has not does not earn the rung. This mutation has reached Policy passed.

1. ✓AI proposalA model asserts this change is beneficial.Not trust on its own
2. ✓Unverified proposalRecorded, but nothing is checked yet.Not trust on its own
3. ✓Source verifiedThe referenced commit and digest resolve.Not trust on its own
4. ✓Build verifiedProvenance shows how the artifact was produced.
5. ✓Tests passedThe adopter’s suite ran green in a sandbox.
6. ✓Policy passedSecurity and licence gates were satisfied.
7. 07Maintainer approvedA human with authority said yes.
8. 08Adopted alleleThe capability now lives in this genome.

Evidence checklist

The six gates a mutation clears before it can be offered onward. Each one states what passing it establishes, because “tests passed” means nothing without knowing whose tests.

• ✓

  Source digest

  clearedSource verified

  The referenced commit and content digest resolve to the same bytes.

• ✓

  Build provenance

  clearedBuild verified

  An attestation shows how the artifact was produced, and by what.

• ✓

  Tests

  clearedTests passed

  The adopter's own suite ran green against the change in a sandbox.

• ✓

  Security policy

  clearedPolicy passed

  No new advisory was introduced and the policy gate was satisfied.

• ✓

  Licence

  clearedPolicy passed

  The change's licence is compatible with the adopting genome's.

• ✗

  Maintainer approval

  not clearedMaintainer approved

  A human with authority over the adopting project said yes.

• ⊹TSTAutomated test. A test suite executed and asserted this behaviour.Adaptive buffer mutation: full parent suite green in an isolated sandbox. (214)2027-01-18 · sha256:8c20af41
• ◉RUNRuntime observation. Measured from a real or sandboxed execution.Latency measured on Chrome, Safari and Firefox with hardware MIDI input. (3)2027-01-18 · sha256:b551d07c
• ⚠SECSecurity scanner. Reported by an advisory database or scanner.No new advisories introduced. Licence expression unchanged.2027-01-18

Measured phenotype

What the change did when it ran, against what it did before. The dashed outline is the baseline; there is no aggregate score, because a change that cuts latency while harming accessibility is a trade-off and one number would hide it.

The change itself

An illustrative before and after, pinned to content digests. The digests are the authoritative part; the excerpt is there to make the shape of the change legible.

Reference digest

sha256:c31f7ba9

Alternate digest

sha256:b551d07c

Commit

commit:e91d4c7a03

Test suites touched

1

const BUFFER_FRAMES = 128;

export class MidiScheduler {
  schedule(event: MidiEvent) {
    const at = this.context.currentTime + BUFFER_FRAMES / this.sampleRate;
    this.voices.start(event.note, at);
  }
}

export class AdaptiveBuffer {
  private window = new JitterWindow(64);

  frames() {
    // Track observed jitter and keep two standard deviations of headroom.
    const p95 = this.window.percentile(0.95);
    return clamp(Math.ceil(p95 * this.sampleRate), 32, 256);
  }
}

Sandbox runs

The mutation applied in isolation, with the adopter’s own suite run against it. This is the step that turns a proposal into a measurement.

• node 22 on ubuntu-24.04 · Chrome 141 · desktop

  pass · 214/214 · 96.4s

  CAEV:991 · sha256:8c20af41

  › applying CAMUT:882 to CAGENOME:01JKEYLIT7H2 @ 82c134bd
  › resolving allele CAALLELE:MIDI-SCHEDULING:5 (sha256:b551d07c)
  › sandbox: microVM, no network, 2 vCPU
  › midi-latency-suite-v3 ......... 214 passed
  › measuring phenotype in 3 browsers
  ›   chrome  p50 19ms  p95 34ms
  ›   safari  p50 21ms  p95 38ms
  ›   firefox p50 20ms  p95 36ms
  › baseline p50 41ms  p95 78ms
  › security policy: pass (0 new advisories)
  › licence: MIT -> MIT, compatible
  ✓ evaluated in 96.4s — awaiting maintainer decision

• node 22 on macos-15 · Safari 19 · laptop

  pass · 214/214 · 112.8s

  CAEV:992 · sha256:b551d07c

  › replaying CAMUT:882 on Safari 19
  › midi-latency-suite-v3 ......... 214 passed
  › jitter-recovery-suite ......... 18 passed
  ✓ no regression detected

Who this applies to

1,284 relatives are eligible and 93 would need manual review, at a parent compatibility of 0.98. Eligibility is not adoption: every one of them decides for itself.

Provenance

Claims bound to immutable artifacts. An attestation is not a promise that the change is good — it is a signed statement about how it was produced, read here as SLSA, in-toto, CycloneDX pedigree and W3C PROV triples.

Decision

A decision is itself a record: attributable, reasoned and signed. Choose one to see what would be written on behalf of KEYLIT.