Context
Tree line B2 (#14564 map). The runner (#14672) times phases from OUTSIDE; this leaf instruments the INSIDE terminus: the exact first-durable-agent-memory event that ends the TTFP clock — the graduated OQ4 metric's defining edge, with the assisted-vs-self-serve split so the metric cannot lie about the product.
The Problem
TTFP's end-edge must be a substrate event, not a log guess: the first successful durable memory write in a fresh deployment, stamped with install-run correlation (so harness runs and real installs measure identically) and the assisted/self-serve flag (the honesty split).
The Architectural Reality
The measurement-first bring-up boundary (graduated, reflexive): the measurement substrate comes up FIRST during install or fresh installs are invisible — so this hook lives at the memory-write path's earliest viable point with a no-op-safe guard when instrumentation config is absent (fail-open, never blocks a write). Placement: the memory-core write seam (structural-pre-flight at claim).
The Fix
One PR: the terminus event emission (JSON-first record: runId?, timestamp, assistedFlag, deploymentClass) + runner correlation (consumes #14672's runId) + specs (event fires exactly once per fresh deployment; absent-config = silent no-op; never on the write's critical path failure mode).
Acceptance Criteria
Out of Scope
The runner (#14672) · METRIC node emission (G1) · time-to-first-PR probe (B3 line).
Related
Parent #14564 (line B2) · consumed by #14672/G1 · OQ4 authority from #14456. Sweeps: 03:47Z clean.
Origin Session ID: fa2a6fd5-7488-4af6-a0d2-3855c86003e4
Retrieval Hint: "TTFP instrumentation first durable memory terminus assisted split"
Context
Tree line B2 (#14564 map). The runner (#14672) times phases from OUTSIDE; this leaf instruments the INSIDE terminus: the exact first-durable-agent-memory event that ends the TTFP clock — the graduated OQ4 metric's defining edge, with the assisted-vs-self-serve split so the metric cannot lie about the product.
The Problem
TTFP's end-edge must be a substrate event, not a log guess: the first successful durable memory write in a fresh deployment, stamped with install-run correlation (so harness runs and real installs measure identically) and the assisted/self-serve flag (the honesty split).
The Architectural Reality
The measurement-first bring-up boundary (graduated, reflexive): the measurement substrate comes up FIRST during install or fresh installs are invisible — so this hook lives at the memory-write path's earliest viable point with a no-op-safe guard when instrumentation config is absent (fail-open, never blocks a write). Placement: the memory-core write seam (structural-pre-flight at claim).
The Fix
One PR: the terminus event emission (JSON-first record: runId?, timestamp, assistedFlag, deploymentClass) + runner correlation (consumes #14672's runId) + specs (event fires exactly once per fresh deployment; absent-config = silent no-op; never on the write's critical path failure mode).
Acceptance Criteria
Out of Scope
The runner (#14672) · METRIC node emission (G1) · time-to-first-PR probe (B3 line).
Related
Parent #14564 (line B2) · consumed by #14672/G1 · OQ4 authority from #14456. Sweeps: 03:47Z clean. Origin Session ID: fa2a6fd5-7488-4af6-a0d2-3855c86003e4 Retrieval Hint: "TTFP instrumentation first durable memory terminus assisted split"