T07: InnerLoop v1.1 — the instrument must emit its own target

Answers the question the workplan posed: did v1.0's "every metric names
its instrument" rule stop a metric being written without a working
instrument? No. AC-1 named `cb-cost --pin` before that tool existed and
set a hand-computed target of $92.87; the tool returned $93.32. The rule
was satisfied completely and the metric was still wrong.

v1.1 adds:
  - the instrument must exist and the target must come out of it;
    targets are provisional until the tool emits them
  - a number inherited from earlier work is re-derived before use as a
    target, or cited as unverified
  - every reporting tool exposes --self-test, run before the number
  - cost is in the definition of done; M-D2-CST may not be uncomputable

The cost of CB-WP-0001 was stated four times before it was right --
$248.46, $92.21, $92.87, $93.32 -- and each correction came from a
different mechanism: re-derivation, adversarial review, and the positive
control. None found more than one. That is the case for keeping all
three.

CB-WP-0003 T10 predicted the next error would be harness-does-nothing.
It was not, twice. Trusted arithmetic over real data would pass a
positive control; and a property verified on 206/206 groups of the main
transcript is false in the 8-response subagent tree that neither the
survey nor the reviewer examined separately. Review structurally cannot
catch the second -- re-deriving on the same sample reproduces the same
blind spot.

Workplan status: done.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

history/260731-cost-accounting-retrospective.md

@@ -0,0 +1,112 @@
+# 2026-07-31 — retrospective: what CB-WP-0002 taught the loop
+
+Pass: CB-WP-0002, cost accounting. Produced `tools/cb-cost.py`,
+`specs/CostAccounting.md`, ADR-0003, CB-EV-0002, and InnerLoop **v1.1**.
+
+## The question the workplan asked
+
+> CB-WP-0001 produced a fully specified metric that could not be computed,
+> and v1.0's "every metric names its instrument" rule was written to stop
+> that. Did it?
+
+**No.** The rule was satisfied completely and the metric was still wrong.
+
+`specs/CostAccounting.md` AC-1 named `cb-cost --pin fc76445` as its
+instrument — a command that did not exist when the row was written — and
+set the target to **$92.87**, computed by hand. When the tool was built one
+task later it returned **$93.32**. The hand computation carried a dedup bug
+that the tool's own positive control caught on first contact.
+
+So the v1.0 rule stops "a metric with no instrument named" and does not stop
+"a metric whose target the instrument never produced". The distinction did
+not exist when the rule was written because the failure it was written for
+was the coarser one.
+
+**v1.1's answer:** the instrument must exist and the target must come out of
+it. Where the tool is built later in the pass, the target is `provisional:`
+until the tool emits it, and the spec is amended to whatever it returns —
+not the reverse.
+
+## The number, and its four corrections
+
+The cost of CB-WP-0001 was stated four times before it was right:
+
+| value | method | what was wrong |
+|---|---|---|
+| $248.46 | inherited, quoted | per-line summation (~1.9×) + single-model pricing |
+| $92.21 | re-derived, deduped, per-model | omitted the subagent tree |
+| $92.87 | + subagent at first-wins dedup | `output_tokens` is a running count |
+| **$93.32** | emitted by `cb-cost` | — |
+
+Each correction was found by a different mechanism, and this is the useful
+part:
+
+1. **$248.46 → $92.21** by *re-deriving instead of quoting*. Now a v1.1
+   rule.
+2. **$92.21 → $92.87** by *adversarial review*, which noticed the target
+   contradicted the survey's own blind-spot finding. Cost: $1.11.
+3. **$92.87 → $93.32** by the *positive control*, which fired on real data
+   and refused to print a number.
+
+No single mechanism found more than one. That is the argument for keeping
+all three rather than consolidating.
+
+## The error class the last pass predicted, and what actually happened
+
+CB-WP-0003 T10 predicted the next error would be the harness-does-nothing
+class, since four instances had already been seen. It was not — twice.
+
+- The two errors in $248.46 were **trusted arithmetic over real data**. Both
+  sums ran over data that genuinely existed. A positive control asserting
+  "did this harness do work?" would have answered yes, correctly, and
+  reported a wrong number.
+- The error in $92.87 was **a property verified on the large sample and
+  assumed on the small one**. The dedup invariant was checked on the main
+  transcript (206/206 groups) by the survey, and independently re-checked by
+  the adversarial reviewer, who also used the main transcript. It is false
+  in the 8-response subagent tree that neither examined separately.
+
+The second is the one worth carrying forward, because **review structurally
+cannot catch it**: the reviewer's job is to re-derive the author's claims,
+and re-deriving on the same sample reproduces the same blind spot. Only an
+assertion running over *all* the data at execution time catches it. That is
+now a v1.1 rule (`--self-test` on every reporting tool, run before the
+number).
+
+## What the pass bought, in its own units
+
+The capability measures itself, which is the first time this project has
+been able to say what a pass cost while the pass was running:
+
+- **CB-WP-0001 (measured retroactively):** $93.32 pinned at `fc76445`.
+  88.0% cache, 11.9% output, 249:1 context re-read to text written.
+- **Adversarial review, this pass:** $1.11 — ~1% of the pass it reviewed —
+  and it found three approval-blocking defects. Second consecutive pass
+  where that trade was decisive. Two data points now support CB-WP-0003 T03.
+- **`/compact`, measured for the first time:** 542,991 → 19,974 tokens, a
+  27× context reduction. Cost per turn fell 3.1×, from $0.457 across the
+  136 turns before it to $0.149 across the 202 after.
+
+That last number changes advice this project was about to give itself.
+CB-WP-0003 T04 was going to prescribe one task per session on the theory
+that long sessions are quadratic. They are **bounded**-quadratic: cost grows
+with context between compactions and resets at each one. The failure mode is
+a long *uncompacted* session, and whether a fresh session beats a compaction
+is now a measurable question rather than a matter of taste. T04 should
+measure it before prescribing.
+
+## Raised, not resolved
+
+- **The price sheet cannot express a time-boxed rate.** Sonnet's intro price
+  is a TOML comment. Costs $0.17 today (0.19%); becomes a real error on
+  **2026-08-31** when the intro rate expires and the comment and the data
+  disagree in the other direction.
+- **32.5% of spend has no task**, because 19 of 33 commits carry no `T##`
+  tag. Reported as its own line rather than hidden, but the underlying fix
+  is commit hygiene, not tooling.
+- **Outside this repo:** the `ralph-workplan` skill instructs agents to read
+  token counts from the Claude Code status bar. That is not readable from a
+  tool call, so an agent asked for it estimates instead — the proximate
+  cause of the hub holding 401,100 tokens for a workplan that actually
+  consumed 80.9M. Flagged for the maintainer; `make cost` is the authority
+  in the meantime.

specs/InnerLoop.md

@@ -1,11 +1,17 @@
 # The Inner Loop — Assimilate and Surpass
 
-Status: **v1.0** — survived its first full pass (CB-WP-0001, the GROUND
-game kernel) and was corrected from it on 2026-07-31. Changes from v0.2:
-measurement validity (the positive control), metric feasibility and
-instrument naming, four implementation rules the pass earned, and the
-requirement that evidence state what it does not support. Rationale and
-the failures behind each: `history/260731-inner-loop-retrospective.md`.
+Status: **v1.1** — corrected from CB-WP-0002 (cost accounting) on
+2026-07-31. Changes from v1.0: the instrument must exist and emit its own
+target; inherited numbers are re-derived before use; every reporting tool
+exposes `--self-test`; cost is in the definition of done. Rationale:
+`history/260731-cost-accounting-retrospective.md`.
+
+v1.0 — survived its first full pass (CB-WP-0001, the GROUND game kernel)
+and was corrected from it on 2026-07-31. Changes from v0.2: measurement
+validity (the positive control), metric feasibility and instrument naming,
+four implementation rules the pass earned, and the requirement that
+evidence state what it does not support. Rationale and the failures behind
+each: `history/260731-inner-loop-retrospective.md`.
 
 Normative process for building every Clay-Borg capability. Referenced by
 all workplans. The loop's own optimization target is **agentic efficiency**:
@@ -122,7 +128,30 @@ research step (metric provenance).
 
 **Every metric names its instrument, and is checked reachable.** A row
 in the acceptance table carries the command that produces its number.
-A metric with no named instrument is a wish, not a metric. A metric must
+A metric with no named instrument is a wish, not a metric.
+
+**The instrument must exist, and the target must come out of it.**
+Naming a command is not the same as running one. A target computed by
+hand and merely *labelled* with a command is the same defect the rule
+was written to stop, one level down. Where the instrument is built later
+in the pass, the target is marked `provisional:` until the instrument
+emits it, and the spec is amended to whatever the instrument returns.
+
+*(v1.1, from CB-WP-0002: `specs/CostAccounting.md` AC-1 named
+`cb-cost --pin fc76445` before that tool existed, and set the target to
+a hand-computed $92.87. When the tool was built it returned $93.32 —
+the hand computation carried a dedup bug the tool's own positive control
+caught. The metric satisfied v1.0's rule completely and was still
+wrong.)*
+
+**A number inherited from earlier work is re-derived before it is used
+as a target, or it is cited as unverified.** Quoting is not measuring.
+
+*(v1.1, from CB-WP-0002: the workplan opened with $248.46, inherited
+from a prior pass. Re-derivation put it at $92.21 — the quoted figure
+double-counted transcript lines and priced a three-model session at one
+model's rate. Neither error was of the harness-does-nothing class; both
+sums ran over real data, and a positive control would have passed them.)* A metric must
 also be checked against the contracts in the *same spec*: if a contract
 makes a target unreachable, one of the two is wrong and the conflict is
 resolved when it is noticed, not at the acceptance run. Re-check the

workplans/CB-WP-0002-cost-accounting.md

@@ -1,7 +1,7 @@
 ---
 id: CB-WP-0002
 title: "Make agentic cost measurable, so D2 claims are falsifiable"
-status: proposed
+status: done
 state_hub_workstream_id: "b7c22f69-fbe9-48df-9619-007db79ae338"
 ---
 
@@ -207,7 +207,7 @@ the one command surface.
 
 ```task
 id: CB-WP-0002-T07
-status: todo
+status: done
 priority: low
 state_hub_task_id: "ebe58d91-be5f-4d5b-ba40-b03275b4eefc"
 ```