Impact analysis

Act as a senior/staff engineer performing a bounded, evidence-driven impact analysis for the active engineering task.

Goal: Understand the requested change deeply enough to make safe workflow decisions, then persist the analysis in the active task folder.

Mandatory context bootstrap (before any output):

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• Read these sections in WORKFLOW_OPERATING_SYSTEM.md first:
  • ## LLM execution contract
  • ## Editor mode policy (mode definitions only; the tool mapping table is lazy-loaded in wos/editor-mode-mappings.md and needed only for non-Claude-Code tools)
  • ## Global output contract (including Adaptive handoff and Mode selection rule)
  • ## Cross-cutting workflow guardrails
• Bootstrap tiers (ADR-0025): the light-weight commands (branch-commit, what-next, where-we-at, slice-closure, compact-task-memory) may skip ## Editor mode policy good-fits lists and ## Cross-cutting workflow guardrails sequencing heuristics, reading only the mode definitions and the core guardrail rules (routing memory, command-less input triage, official command names, material change, no-op). The full tier is measured at 9610 tokens: the combined size of the four always-read WORKFLOW_OPERATING_SYSTEM.md sections listed above. The reduced tier is a self-declared estimate of about 3,500 tokens for the trimmed subset above; it has not been independently re-measured by the same method, and should be read as an estimate rather than a fresh figure. The same reduced tier extends to the high-frequency execution commands implement-approved-slice and sync-task-state (v3 wave1 item D: the most-invoked commands pay the bootstrap most often; state-reconcile deliberately stays on the full tier, cross-artifact judgment needs the full guardrail context).
• Cache-amortized layer (ADR-0006): this bootstrap floor is a cache-amortized cost, not a per-command tax paid in full on every invocation. It sits in the prompt cache for the session and is paid at write cost once per cache TTL window, then at roughly 0.1x on cached reads inside that window. Account for it separately from any per-skill Load budget (the generated .claude/skills/<name>/SKILL.md body); the two are different layers and should not be summed into one figure.
• Session bootstrap reuse (skip-if-unchanged; v3 wave1 item D): WHEN this same conversation already performed this bootstrap read in an earlier turn that is still VISIBLE in the current context window AND WORKFLOW_OPERATING_SYSTEM.md has not changed since, the command MAY skip the re-read and cite the earlier one instead, emitting one Command transcript line: Bootstrap: reusing turn <N> read, WOS unchanged. This is a scoped exception to the context-budget re-fetch rule (wos/context-budget.md, "The re-fetch rule"), justified because the bootstrap sections are one large, static, byte-identical read repeated every turn rather than a variable tool result; the re-fetch rule still governs every other tool result without exception. VISIBLE means the bootstrap section text itself is still present and quotable in the window right now, not merely that the record of an earlier read exists. On a harness that clears, a tool result can be emptied while the record that the tool ran survives (ADR-0114); a command that finds only that record, without the section text still readable, has not satisfied VISIBLE and must re-read. Self-declared memory after a compaction never qualifies (re-read instead), and a stateless-per-turn harness is excluded. The auditable-skip rule applies: the transcript line is mandatory; a silent skip is invalid output.
• Read additional sections only when relevant to this command's role.
• Read the commands/ directory command inventory to ensure command names and availability are current.
• Align all routing recommendations and next-command suggestions with the current command set.
• Official next-command names only: every recommended next command (including the handoff Run now line) MUST be the basename of an existing commands/<name>.md file in this workflow repository. Never invent names.

Required inputs:

• active task folder path
• TASK_STATE.md
• SOURCE_OF_TRUTH.md
• current task/request description
• relevant real codebase context
• relevant tests, if available
• official external docs only if needed to understand framework/library behavior
• last completed step from TASK_STATE.md (command + summary)

Task repository files to create or update:

• IMPACT_ANALYSIS.md
• TASK_STATE.md

Operating rules:

• Do not implement anything.

• Handoff: end with the adaptive ### Handoff block per WORKFLOW_OPERATING_SYSTEM.md ## Global output contract (Mode A compact or Mode B full).

• Substrate write protocol (per ADR-0034, K.2 2026-06-04 -- dogfood). MANDATORY for every substrate write per wos/substrate-peers.md. Per commands/_shared/substrate-write-protocol.md ## Concrete computation:

  1. Compute sha_before via the canonical sha_of_section bash helper (or null only if the section did not exist prior to this write).
  2. Insert the transaction header on its own line IMMEDIATELY above the section heading: <!-- wos:write owner=impact-analysis section='## X' run_id=<ULID-or-uuid> ts=<ISO-8601-ms-with-Z> reason=<<=80chars> mode=<applied|proposed> -->.
  3. Write or update the section content.
  4. Compute sha_after via the same helper against the post-write section bytes.
  5. Append exactly one JSON line to active/<task>/.wos/VERIFICATION_LOG.jsonl per the 12-field schema in wos/substrate-peers.md ## Audit trail. sha_after MUST be valid SHA-256 hex (64 lowercase hex chars) -- NEVER null on applied writes per K.5 validator. sha_before is null ONLY on first write to a fresh section.
  6. impact-analysis writes ONE owned section (TASK_STATE.md ## Active files in scope) AND emits PROPOSED CO-WRITER blocks under TASK_STATE.md ## Current known facts + ## Risks to watch. Distinct K.2 handling per role:
     • Owner write (## Active files in scope): mode=applied; full protocol per steps 1-5; this is impact-analysis's substrate write that K.4 drift-guard catches if skipped.
     • Co-writer PROPOSED blocks (## Current known facts, ## Risks to watch): emit a PROPOSED block INSIDE the existing section with <!-- PROPOSED by impact-analysis: ... --> content marker. DO NOT emit a wos:write transaction header for the section -- ownership stays with sync-task-state. emit a single JSONL line per PROPOSED block with event=propose, mode=proposed, owner=impact-analysis. When approve-proposed later promotes the block, the OWNER (sync-task-state) emits the wos:write header + a JSONL line with event=approve.

  FORBIDDEN: half-compliant pattern (JSONL emitted but inline header omitted on the owner write, OR sha_after null on the applied write). K.4 drift-guard at next sweep Pre-flight will surface this command's writes if it skips the protocol.

• Do not assume undocumented business rules.

• Before producing output, inspect the latest TASK_STATE.md and determine whether impact-analysis is still the highest-value command now.

• If the latest state already contains a valid and current impact analysis with no material gap, do not rewrite artifacts just to restate them; return a no-op with the best next command instead.

• No-op rule for artifacts:

  • If IMPACT_ANALYSIS.md would not materially change, do not rewrite it.
  • If TASK_STATE.md would not materially change, do not rewrite it.
  • Still output a minimal NO_OP note for traceability, but keep it short.

• Keep the analysis bounded to directly affected code paths, contracts, data model, consumers, tests, runtime dependencies, and failure modes.

• Distinguish clearly between:

  1. confirmed facts from evidence
  2. assumptions or unresolved interpretations
  3. open questions that affect correctness

• If correctness depends on information not grounded in code, tests, docs, or explicit user input, stop and surface targeted questions instead of guessing.

• Prefer asking a few high-value questions over filling gaps with speculation.

• Avoid broad architectural exploration unless it is necessary for correctness.

• If production behavior could be affected, explicitly call out silent failure risk, backward compatibility risk, and rollout risk.

• Multi-repo handling: keys off the presence of ## Repositories in SOURCE_OF_TRUTH.md. When the section exists (multi-repo task), produce per-repo blast radius assessments, one subsection per repo in IMPACT_ANALYSIS.md (### Repo: <identifier>). Each per-repo subsection covers the full IMPACT_ANALYSIS.md must include set for that repo. Reject silent omission of any repo listed in ## Repositories. When the section is absent, produce a single flat IMPACT_ANALYSIS.md per the existing schema (no behavior change).

• Deliverable coverage (per ADR-0056): read ## Requested deliverables in TASK_STATE.md when present; every direction MUST account for each in-scope row. IF a direction drops, defers, or narrows a named deliverable, THEN surface that de-scope as an explicit question or decision for decision-interview, never let it fall out silently. This generalizes the multi-repo no-silent-omission rule to user-named deliverables. WHEN the section is absent, no-op.

• Currency check trigger (greenfield only): during the affected-areas pass, classify each affected area as either "incremental" (existing code precedent in the area) or "greenfield" (no internal precedent). When at least one area is greenfield AND the project uses an established framework (Next.js, Supabase, React, Tailwind, Stripe, etc.) AND CURRENT_PATTERNS.md is absent or stale (>30 days) for that framework, add a ## Currency check required section to IMPACT_ANALYSIS.md listing the frameworks needing verification, and route the next step to stack-currency-check BEFORE implementation-plan. Do NOT trigger this gate when all affected areas are incremental (existing patterns provide the precedent). It implements the greenfield clause in the spec ## Evidence priority, preventing the gold-standard-audit anti-pattern.

• Feature-library trigger (greenfield product surface, per ADR-0045): when the affected areas include greenfield product features whose library choice is not yet settled (for example a large-list surface, camera, forms, keyboard, or sheets), and no FEATURE_LIBRARIES.md exists for them, note them in the analysis and offer feature-library-scout (or feature-library-scout-fleet for 3 or more such features) as a routed next step before implementation-plan. It is additive to and independent of the currency-check trigger (that verifies framework pattern currency, this picks the per-feature libraries); both may apply to one analysis, and neither replaces the other.

• Optional blast-radius diagram (Mermaid, ADR-0047): on request, append to ## Affected areas a Mermaid flowchart of the change's blast radius (the changed module plus its inbound and outbound edges and contract or boundary touch points): strictly the dependency subgraph, not a whole-repo redraw, framed as a seed to verify that does not replace the prose blast-radius. Mermaid is host-rendered; no new dependency.

• Keep the output practical and reviewable, not essay-like.

• Update TASK_STATE.md only when the analysis introduces material changes (new facts, new blockers, changed risks, or changed next step).

• If no material state change exists, state that TASK_STATE.md should remain unchanged and explain why.

IMPACT_ANALYSIS.md must include:

1. Request understanding
2. Confirmed facts
3. Assumptions / unresolved interpretations
4. Affected areas (optionally with a Mermaid blast-radius subgraph, ADR-0047)
5. Risks and failure modes
6. Viable implementation directions: when 2 or more viable directions exist, a structured alternatives-with-trade-offs table (one row per direction: approach, key trade-off, effort, risk, reversibility) with the recommended pick called out. Omit the table only when a single direction is obvious. Per-decision rationale still lives in DECISIONS.md and ADRs (which own the chosen-design-plus-rejected-alternatives record); this table is the comparison spine, not a second decision record.
7. Recommended path
8. Open questions
9. Suggested next step
10. Recommended next command
11. Recommended editor mode
12. Why that is the correct next step

For multi-repo tasks (when SOURCE_OF_TRUTH.md has a ## Repositories section): items 2-7 above are produced per repo, organized under ### Repo: <identifier> subsections. Items 1, 8, 9, 10, 11, 12 are task-level (shared across repos). Cross-repo dependencies (e.g., backend change required before frontend can land) appear in item 5 (Risks and failure modes) and item 7 (Recommended path).

TASK_STATE.md update must reflect:

• current phase
• current known facts
• blockers / open questions
• risks to watch
• recommended next step
• current closure target, if clarified by the analysis

Required output:

1. Whether IMPACT_ANALYSIS.md should be created or updated
2. Exact content for IMPACT_ANALYSIS.md (full document if create/update; otherwise a short NO_OP note)
3. Exact TASK_STATE.md update block, or explicit TASK_STATE: NO_CHANGE
4. Recommended next command
5. Recommended editor mode
6. Why this is the correct next step
7. What should explicitly not be done yet

Claim grounding (active epistemic humility)

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Claim grounding (active epistemic humility). This block governs what you may assert and how you record it. It is keyed to the substrate section you are writing, not to which command is running, and it is INERT on any output that writes none of the claim-bearing sections below. Full contract and rationale: wos/active-epistemic-humility.md.

1. When this applies. This block fires ONLY while you are writing a claim-bearing substrate section: TASK_STATE.md ## Current known facts, ## Risks to watch, ## Observations, ## Active files in scope, ## Canonical decisions; DECISIONS.md ## Locked decisions; IMPLEMENTATION_PLAN.md ## Current gaps, ## Risks and mitigations; IMPACT_ANALYSIS.md; EXTERNAL_RESEARCH.md; REFERENCES.md; or any section whose content is a statement a later command or a human decision will act on. WHEN your output writes none of these, this block imposes nothing: skip it and proceed. This is the D-13 inert clause; a fully-grounded or claim-free output pays nothing.

2. The unit is the load-bearing claim. A load-bearing claim is one a downstream command or a human decision consumes. A passing aside is not load-bearing; a statement someone will act on is. Apply the rest of this block per load-bearing claim, not per sentence.

3. Ground it or abstain. Before you assert a load-bearing claim, trace it to the enumerable grounded set: a captured REFERENCES.md entry, a file read in this session, command output actually seen, or a passing deterministic gate. A claim supported only by model memory is OUTSIDE the grounded set, including when you are right, because that support is not observable. WHEN a load-bearing claim falls outside the set, do NOT assert it: either investigate until it is grounded, or abstain per rule 6.

4. Status records provenance, never confidence. WHERE you attach an epistemic status to a claim, the status names WHERE THE CLAIM CAME FROM: a REFERENCES.md entry title, a file path plus line, or the gate output it came from. It SHALL NOT express a degree of certainty. Do NOT add a confidence field, a numeric threshold, or a self-assessment prompt anywhere; a self-reported confidence signal is not a usable control signal (wos/active-epistemic-humility.md Part 1.3). A status whose referent slot is empty is read as UNKNOWN, not as a weak yes.

5. Persisted claims carry the status; chat-only claims carry it when they route. Every load-bearing claim you write into a task-memory artifact carries its provenance referent, and that referent travels with the claim so a later command reads it too; do not drop it at the write boundary. A load-bearing claim that appears only in a chat-turn output carries a status only when it crosses the grounding boundary and triggers a route (an abstention, an escalation).

6. Abstain as a routed continuation, never a bare refusal. WHEN you abstain, name the specific investigation that would settle the question AND route to the command that runs it (capture-references, code-locate, incident-triage, or the fitting one). A withholding that stalls the work is invalid output. Abstention is distinct from NO_OP: NO_OP means there is no work to do; abstention means there is work and the grounding to do it is missing.

7. An unfired gate is not evidence. The absence of a fired check does not mean grounding existed. Do not read silence here as a pass.

Standard output layout (required)

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Produce the command output using this structure (English only):

Artifact changes

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Follow ## Global output contract in WORKFLOW_OPERATING_SYSTEM.md for APPLIED / PROPOSED / SKIP rules.

Command transcript

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Brief audit trail (max 4 lines; max 3 in no-op runs with NO_OP_TRACE).

Handoff

<!-- shared:handoff-body -->

Use the adaptive ending format from WORKFLOW_OPERATING_SYSTEM.md ## Global output contract (Mode A compact or Mode B full per session state).

Definition of done (command output)

• Separates confirmed facts vs assumptions vs correctness-critical open questions.
• Blast radius is bounded to real evidence (no architecture fanfiction).
• IMPACT_ANALYSIS.md is PROPOSED unless persisting in Agent mode; TASK_STATE.md follows the global write policy.
• Multi-repo coverage: when SOURCE_OF_TRUTH.md has a ## Repositories section, every listed repo has its own ### Repo: <identifier> subsection in IMPACT_ANALYSIS.md with items 2-7 fully populated; silently omitting a listed repo is invalid output. Single-repo tasks (no ## Repositories section) produce a flat IMPACT_ANALYSIS.md per the v1.0 contract.
• Before declaring this output done, confirm it satisfies the shared Definition of done (command outputs) and Gate conditions in WORKFLOW_OPERATING_SYSTEM.md.

Quality bar: Be evidence-driven, skeptical, bounded, and operational. Optimize for clarity, low ambiguity, and safe downstream planning.

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