git:20260909.600c2eb to git:20260910.3b9a68e

---

name: implement

description: 'Implement authorized work and repair understood defects; return derived subject identity and check facts. Triggers: "implement", "implement this bead", "run the experiment". Full plan-to-validation requests route to rpi.'

practices:

- tdd

- refactoring

- small-batch-flow

hexagonal_role: driving-adapter

consumes: []

produces:

- subject-manifest.v1

output_contract: 'subject-manifest.v1 digest, author context ID, and exact acceptance-check receipts returned through the response or runtime channel'

context_rel:

- kind: customer-of

with: plan

skill_api_version: 1

user-invocable: true

metadata:

graph_root: true

tier: execution

dependencies: []

capabilities: [execute_one_experiment, collect_factual_evidence]

effects: [modify_declared_subject, derive_subject_manifest]

canonical_status: canonical

disposition: keep

---

# Implement

Implement the accepted outcome. Repair ordinary known defects directly. Use the existing

intent; no Plan, Recall or Learn worksheet is owed for a clear edit. Implement

owns source changes and factual checks; the runtime derives identity and receipts.

## Workflow

1. Read intent, acceptance, scope and the RPI [boundaries](../rpi/references/boundaries.md)

before the first write; reuse contracts already loaded in this context.

When the caller selected episode tracking, obtain permitted work/source

references before execution and return observed runtime/context identity at

startup through the native recording channel. Unknowns and recording failures

stay explicit; do not invent parentage or a second tracker. The optional

[session association reference](../cass/references/SESSION_FORMATS.md#work-to-session-associations)

supplies mechanics for that selected workflow.

the expected missing behavior; a pure refactor, relocation or documentation

change may have an honest green baseline. Avoid building elaborate fixtures

when an existing test or small discriminating probe answers the question.

3. Make the smallest in-scope change. Fix known failures directly, then rerun

the affected check. A disproved assumption may change the approach within

accepted outcome and scope; use Plan only for consequential uncertainty.

4. Use targeted tests and applicable repository lint/static checks before

broad integration. Read the repository's actual check recipe, including

instrumentation and environment, rather than reconstructing it from memory.

Run required full checks at integration, not after each small edit. Reuse

exact-input receipts only while source, tool and relevant environment match.

5. Refactor while acceptance remains green. Inspect changed tests, fixtures,

goldens, tolerances, suppressions and specification text against original

intent. Mocks, placeholders or weakened oracles cannot substitute for the

requested behavior.

6. Have the runtime derive actual changed paths and `subject-manifest.v1`. When changed paths

affect bound acceptance evidence, run `ao provenance evidence-orphans --root

<repo-root>` with one `--changed <path>` per derived path, and retain the

actual output for the validator. Repeat after repairs that change that

subject; do not hand-invent an orphan list.

7. Return the manifest digest, author context ID, acceptance-check facts and

evidence references through the caller's response/runtime channel, then stop.

Include command, result and decision-relevant failures. Keep full output

accessible instead of pasting successful logs or repeated receipt inventories

into every handoff. Missing or truncated evidence must remain visible.

## Scope and finish

Report an uncovered live consumer as `file:line` for a caller scope amendment;

continue independent authorized work. Generated companions already included as

scope require no new approval. Acceptance changes always require caller authority.

Specialists advise only. Known defects stay implementation work; a genuine

causal stall follows RPI's at-most-one bounded helper rule. Respect remaining

caller/native bounds and reserve finishing capacity. No retry resets them.

Return facts, not semantic PASS. An implement-only handoff does not authorize

Git, tracker or delivery transitions; existing caller authority remains usable.

A full outcome request uses RPI through fresh final judgment. Success is working

behavior with usable evidence, not volume of logs or process artifacts.