# CC-upgrade decision matrix — Claude Code 2.1.130 → 2.1.181

**Scope:** Evaluate every relevant Claude Code change shipped between 2.1.130 and 2.1.181 (latest as of 2026-06-18) against Voyage v5.1.1, and decide adoption per change.
**Precedent:** This continues the F2–F14 feature-adoption process referenced in the roadmap ("ny CC-versjon med relevant feature → vurder adopsjon analogt med F2–F14-prosessen"). The F-catalogue came from the extracted `ultra-cc-architect` plugin and is no longer bundled; this matrix is a fresh, self-contained catalogue (`CC-NN`) for the 2.1.130→181 window.
**Method:** Two-track research (CC changelog digest + Voyage CC-capability surface inventory), synthesized in a single context. Sources: official changelog (`code.claude.com/docs/en/changelog.md`) + canonical `anthropics/claude-code` CHANGELOG.

## Provenance & verification (verifiseringsplikt)

- **Verified verbatim against the official changelog** (load-bearing claims): `2.1.172` sub-agent nesting; `2.1.154` Opus 4.8 + dynamic workflows; `2.1.166` SendMessage authority; `2.1.178` `Tool(param:value)` syntax; `effort:` frontmatter (`2.1.154`/`2.1.152`).
- **From changelog research, not independently re-verified line-by-line:** all other entries below. Where a decision *hinges* on an unverified claim, it is marked ⚠️ and routed to EVALUATE, never SHIP.
- **Note on 2.1.130–2.1.135:** these versions are not in the public changelog (public window begins 2.1.136). No user-facing entries to evaluate.

## Decision legend

| Decision | Meaning |
|----------|---------|
| **SHIP** | Adopt now — clear fit, low risk, no open design question. |
| **EVALUATE** | Needs an empirical test or a design decision before ship/skip. The hard architectural items live here — honest, not deferred-by-another-name. |
| **DEFER** | Adopt later; trigger noted. Not weekend-critical. |
| **SKIP** | Not applicable or rejected; reason noted. |

## Workstream legend

| WS | Theme | Weekend-shippable? |
|----|-------|--------------------|
| **W0** | Correctness/trust — fix now-false documentation | Yes |
| **W1** | Orchestration architecture — delegated spawning / Workflow adoption | No (multi-week, empirical) |
| **W2** | Model & effort alignment (Opus 4.8 + native `effort:`) — **gates v5.4** | Partial |
| **W3** | Guardrails & hooks | Partial |
| **W4** | Free wins & release hygiene | Yes |

---

## W0 — Correctness / trust (the headline)

| ID | Change (version) | Type | Voyage relevance | Decision | Rationale |
|----|------------------|------|------------------|----------|-----------|
| **CC-01** | Sub-agents can spawn their own sub-agents, up to 5 levels deep (**2.1.172**, verified); foreground subagents respect the same depth cap (2.1.181) | BREAKING-premise | Voyage's v2.4.0 inline-orchestration migration is justified in 4 places by the claim "the harness does not expose the Agent tool to sub-agents" → `agents/planning-orchestrator.md:5–11`, `agents/research-orchestrator.md:5–10`, `agents/review-orchestrator.md:5–12,:220`, `commands/trekplan.md:399–406`. **That claim is now factually false.** | **SHIP** (doc correction) | Independent of the architecture decision (W1), the docs assert an impossibility that is now possible. Correct the four sites to state the factual position: as of CC 2.1.172 sub-agents *can* spawn sub-agents (≤5 deep); Voyage currently still orchestrates inline; re-architecture is under evaluation (W1/CC-26). Do **not** silently delete — replace with truth + forward pointer. The *design* response is CC-26 (EVALUATE). |

---

## W4 — Free wins & release hygiene (weekend-shippable)

| ID | Change (version) | Type | Voyage relevance | Decision | Rationale |
|----|------------------|------|------------------|----------|-----------|
| **CC-02** | MCP `tools/list` pagination fixes (2.1.144/147); `MCP_TOOL_TIMEOUT` raises remote fetch timeout (2.1.142); sub-1000ms `timeout` now ignored→default (2.1.162) | FIX | research agents (`docs-researcher`, `*-researcher`) use tavily/ms-learn/gemini MCP | **SHIP** (verify) | Automatic benefit — no code change. Verify research agents still enumerate tools correctly under paginated servers. |
| **CC-03** | `SendMessage` relayed messages lose user authority (**2.1.166**, verified) | BREAKING | Voyage uses `SendMessage` **nowhere** (confirmed by inventory) | **SKIP** | No impact. Recorded so a future `SendMessage`-based design knows the constraint up front. |
| **CC-04** | Subagent frontmatter `mcpServers` now enforce `--strict-mcp-config` + enterprise allow/deny (2.1.153) | CHANGE | Voyage ships **no `.mcp.json`** and declares MCP *tool grants* (`mcp__tavily__…`) not server *configs*; agents degrade gracefully when servers absent | **EVALUATE** (low) | Likely no impact, but confirm research agents degrade cleanly under `--strict-mcp-config`. One quick test. |
| **CC-05** | Fable 5 `[1m]` model-name suffix normalized automatically (2.1.173) | FIX | Voyage pins the `opus` alias, not raw ids | **SKIP** | No action; noted for completeness. |
| **CC-06** | `claude plugin validate` flags `skills:` pointing at a file vs dir (2.1.145); richer `claude plugin details` (2.1.143/145) | NEW | release process | **SHIP** (process) | Add `claude plugin validate` to the pre-release checklist. Voyage ships no skills, but validate also checks manifest/components. |
| **CC-07** | `fallbackModel` setting — up to 3 ordered fallbacks; `--fallback-model` now applies to interactive too (2.1.166) | NEW | `trekexecute` headless children (`claude -p`) could gain resilience to model-overload | **DEFER** | Real value for long headless waves. Trigger: when we touch `trekexecute` Phase 2.6 launch flags (or in W2 model work). Not weekend-critical. |
| **CC-08** | Hooks may not fire reliably in headless child sessions — Voyage documents GH #36071 (`trekexecute.md:341`, `templates/headless-launch-template.md:48`) | (status unknown) | safety-preamble is the headless defense if hooks don't run | **EVALUATE** ⚠️ | Changelog does **not** confirm #36071 is fixed. Verify current status before relaxing the in-prompt safety preamble. Until verified: keep the preamble. |
| **CC-09** | `--safe-mode` / `CLAUDE_CODE_SAFE_MODE` — start with all customizations disabled (2.1.169) | NEW | dev/test aid — reproduce "bare harness" behavior | **DEFER** | Useful for regression-testing Voyage against an unconfigured harness. Adopt into test tooling when convenient. |

---

## W3 — Guardrails & hooks

| ID | Change (version) | Type | Voyage relevance | Decision | Rationale |
|----|------------------|------|------------------|----------|-----------|
| **CC-10** | `Tool(param:value)` permission syntax, e.g. `Agent(model:opus)` (**2.1.178**, verified) | NEW | Voyage pins `opus` in 23 agent frontmatters *by convention*; this could enforce it as a hard permission rule | **DECIDED (design note)** ⚠️ | **Trap:** a blanket `Agent(model:opus)`-style rule conflicts with the `balanced`/`economy` profiles, which deliberately spawn `sonnet`. Any enforcement must be **profile-aware** → tie to W2. Do NOT ship a blanket opus-lock. **S2 resolution: no rule added; deferred into W2** — see §S2 resolutions. |
| **CC-11** | `disallowed-tools` in command/skill frontmatter (2.1.152, verified) | NEW | tighten per-command tool surfaces (e.g. ensure `trekexecute` can't spawn Agents — it already documents "no Agent tool") | **SHIPPED ✅** | Promote existing *documented* tool exclusions into *enforced* `disallowed-tools`. Small, defense-in-depth. **S2: added `disallowed-tools: Agent, TeamCreate` to `trekexecute` frontmatter** (the only command with a documented exclusion). Verified `allowed-tools` omission does NOT remove a tool from the pool — `disallowed-tools` does. |
| **CC-12** | Stop/SubagentStop hooks can return `hookSpecificOutput.additionalContext` without being a hook error (2.1.163) | NEW | `post-compact-flush.mjs` already emits `additionalContext`; SubagentStop is a new surface | **DEFER** | Possible richer continuity injection. No current gap forces it. |
| **CC-13** | Stop/SubagentStop hook input now includes `background_tasks` + `session_crons` (2.1.145) | NEW | `otel-export.mjs` (Stop hook) observability | **DEFER** | Could enrich exported telemetry. Adopt when next touching the exporter. |
| **CC-14** | Hook `args: string[]` exec-form — no shell, no quoting (2.1.139) | NEW | Voyage's 7 hooks invoke node scripts via shell form with `${CLAUDE_PLUGIN_ROOT}` paths | **SHIPPED ✅** | Exec-form removes a class of path-quoting bugs. **S2: migrated all 7 hooks** in `hooks/hooks.json` to `{command:"node", args:["${CLAUDE_PLUGIN_ROOT}/…"]}`. Official hooks doc recommends exec-form *"whenever the hook references a path placeholder"* — protects consumers who install Voyage under a path containing spaces. `${CLAUDE_PLUGIN_ROOT}` interpolates in `args` (verified). |
| **CC-15** | Hook `if:` conditions for Read/Edit/Write paths now match reliably (2.1.139/176); reopens deferred **F2** (scope pre-bash/pre-write executors to execute sessions) | FIX | `pre-bash-executor.mjs`, `pre-write-executor.mjs` are currently universal | **DECIDED (keep universal)** | F2 was deferred with "universal protection wins." The `if:` mechanism now works, so the *option* is real again — but the original rationale holds. **S2 resolution: KEEP UNIVERSAL.** These guardrails (rm -rf /, fork bombs; writes to ~/.ssh, .env, .git/hooks) are session-agnostic safety; narrowing to execute-only would only weaken protection with no benefit and never interferes with brief/research/plan work. Header comments corrected to state the universal scope. |
| **CC-16** | `SessionStart` `reloadSkills` + `sessionTitle` (2.1.152) | NEW | Voyage sets session title via `UserPromptSubmit` (`session-title.mjs`) | **SKIP** | Current mechanism works and is command-scoped (title reflects the invoked `/trek*` command). SessionStart-title would fire before the command is known. No gain. |
| **CC-17** | Hook `terminalSequence` output — notifications/bells without a TTY (2.1.141); `continueOnBlock` for PostToolUse (2.1.139); `MessageDisplay` event (2.1.152); Stop block-cap 8 (2.1.143) | NEW | minor ergonomics; Voyage hooks are fail-open and non-interactive | **SKIP/DEFER** | No current need. `MessageDisplay`/`continueOnBlock` SKIP (no use case); `terminalSequence` DEFER (could notify on long headless waves). Block-cap is informational. |

---

## S2 resolutions (W3 hardening — 2026-06-18)

S2 shipped the mechanical W3 items and recorded the two W3 decisions. Schemas verified verbatim against the official slash-commands and hooks docs before any edit (the casing of `disallowed-tools` and exec-form `${CLAUDE_PLUGIN_ROOT}` interpolation are both load-bearing; a first-pass assistant claim of `disallowedTools` camelCase was caught and corrected against the doc).

- **CC-14 — SHIPPED.** All 7 hooks in `hooks/hooks.json` migrated to exec-form (`command:"node"`, `args:["${CLAUDE_PLUGIN_ROOT}/hooks/scripts/X.mjs"]`). `tests/hooks/hooks-json-stop-wired.test.mjs` updated to be form-agnostic (normalizes `command`+`args` to one invocation string). 578/580 pass, 0 fail.
- **CC-11 — SHIPPED.** `disallowed-tools: Agent, TeamCreate` added to `commands/trekexecute.md`, promoting its documented "No Agent tool, no TeamCreate, no delegation" rule from prose to enforcement. Key fact: `allowed-tools` grants auto-approval but does **not** remove tools from the pool (doc, slash-commands.md), so the prior omission left Agent callable; `disallowed-tools` removes it. trekexecute is the only command with a documented exclusion (trekplan's "never spawn more agents than warranted" is an adaptive-count guideline, not an exclusion — trekplan legitimately uses Agent).
- **CC-15 — DECIDED (keep universal).** F2 stays deferred: `pre-bash-executor.mjs` / `pre-write-executor.mjs` remain universal. Rationale re-affirmed explicitly now that `if:` works — narrowing to execute-only sessions would weaken session-agnostic safety with no benefit. Header comments corrected to state the universal scope by design.
- **CC-10 — DECIDED (design note; no code).** Do **not** add a `permissions.deny` rule like `Agent(model:opus)`. Such rules live in `settings.json` permissions (colon separator inside parens, confirmed 2.1.178), not in frontmatter, and a blanket opus-lock would break the `balanced`/`economy` profiles that deliberately spawn `sonnet`. If model-enforcement is ever wanted, it must be **profile-aware** and emitted as part of the W2 model/effort work (S3/S4) — e.g. a profile could ship its own `availableModels`/deny set. Until then, the `model: opus` convention in the 23 agent frontmatters stays advisory. Folded into W2 open question #3.

## W2 — Model & effort alignment (gates v5.4)

| ID | Change (version) | Type | Voyage relevance | Decision | Rationale |
|----|------------------|------|------------------|----------|-----------|
| **CC-21** | **Opus 4.8** available; `opus` defaults to high/xhigh effort (**2.1.154**, verified) | NEW | All 23 agents + 7 commands pin `model: opus` → now resolve to 4.8 at a higher default effort | **DECIDED (S3)** | Accept Opus-4.8-`high` as the new baseline (verified: opus default = `high`). The moderation lever is native `effort:` (CC-22 option C). Doc follow-up: update model/effort references in `CLAUDE.md`/`docs/profiles.md`/README. See §S3 resolutions. |
| **CC-22** | Native `effort:` frontmatter on agents/skills/commands + 5 levels low/medium/high/xhigh/max (**2.1.149/154**, verified) | NEW | Voyage **reinvented** effort as `phase_signals` (low/standard/high) + the `phase-signal-resolver.mjs`/`resolver.mjs` system (which carries the MAJOR doc/code-inconsistency finding) | **DECIDED (S3): option C** | **Resolved.** The (a)-map premise was false: Voyage `effort` = *orchestration-shape* (which agents/passes/gates run, consumed by command prose), native `effort:` = *per-spawn reasoning budget* — **different axes, same name.** Decision: **freeze `phase_signals.effort` 3-level (low/standard/high) as-is** (unblocks v5.4) and adopt native `effort:` **additively at the agent/profile layer, outside the brief contract.** Field name kept `effort` (no breaking rename) + distinction documented. Does NOT retire the resolver MAJOR (that's model-gating, independent — S4). See §S3 resolutions. |
| **CC-23** | Claude Fable 5 (Mythos-class) GA (2.1.170) | NEW | Voyage is a planning/reasoning pipeline; Fable is a different model class | **SKIP** (revisit) | Not an obvious fit for deep-planning agents. Note as an option if a future profile wants a distinct model class for a specific phase. |
| **CC-24** | `enforceAvailableModels` managed setting (2.1.175); `availableModels` now constrains Default + subagent overrides (2.1.172/176) | CHANGE | enterprise deployments could constrain Voyage's `opus`/`sonnet` picks | **DEFER** | Document that profile model picks must live within any managed `availableModels` allowlist. Relevant for enterprise consumers post-open-release. |
| **CC-25** | `MAX_THINKING_TOKENS=0` / `--thinking disabled` disables thinking on think-by-default models (2.1.166) | NEW | could gate thinking in cheap `economy`-profile phases | **DEFER** | Minor cost lever; fold into W2 profile design if useful. |

---

## S3 resolutions (W2 effort/model alignment — 2026-06-18, operator-gated)

S3 was a decision-gate. Two-track evidence (codebase map of `phase_signals`/`phase_models`/profiles/resolver + verbatim-cited CC native-`effort:` semantics) overturned CC-22's framing hypothesis and the operator confirmed the path.

**The load-bearing finding — two axes, one name.** Voyage's `phase_signals.effort` (low/standard/high) is consumed only by **command prose** to pick *orchestration shape*: skip/add swarm passes, gate strictness, sequential-vs-parallel (`trekplan.md:925–957`, `trekresearch.md:472–503`, `trekreview.md:385–417`, `trekexecute.md:1542–1577`). CC native `effort:` (low/medium/high/xhigh/max) is a *per-spawn reasoning-token budget* applied by the harness. `low` in Voyage means "run fewer agents," not "think less." A remap (option a) would conflate the two and silently delete orchestration behavior — and would **not** remove the resolver (it also carries the model half). Verified native semantics: `effort:` settable in agent/skill/command frontmatter; precedence env (`CLAUDE_CODE_EFFORT_LEVEL`) > frontmatter > session > model default; Opus 4.8 default = `high`.

**Operator decisions (2026-06-18):**
1. **CC-22 → option C.** Freeze `phase_signals.effort` 3-level as-is (it is an orchestration axis, deliberately not the native 5-level vocab) → **unblocks the v5.4 brief-schema freeze**. Adopt native `effort:` additively, at the agent/profile layer, outside the brief contract.
2. **Field name kept `effort`** (no breaking rename at v5.4); the orchestration-vs-reasoning distinction is documented loudly instead.

**Dispositions feeding S4 / v5.4 / profile design:**
- **CC-21 — DECIDED.** Opus-4.8-`high` is the accepted baseline; native `effort:` is the moderation lever. Doc-truth follow-up: model/effort references in `CLAUDE.md`/`docs/profiles.md`/README.
- **CC-24 — DEFER (confirmed).** `availableModels`/`enforceAvailableModels` constrains **model only**, not effort (verified). Document that profile model picks must stay within any enterprise allowlist.
- **CC-25 — DEFER (confirmed).** `MAX_THINKING_TOKENS=0` overrides effort (disables thinking) — the most aggressive `economy` cost lever; fold into profile design.
- **Resolver MAJOR (S4, unchanged).** `phase-signal-resolver.mjs:40` copies `model` ungated while `:39` gates `effort`. Independent of the effort decision; option C keeps `phase_signals.model`, so the fix (import + apply `BASE_ALLOWED_MODELS`) stays on S4.

**S4 scope (now unblocked):** (1) resolver MAJOR model-gate fix; (2) additive native `effort:` — verified-safe minimum is static per-agent frontmatter (retrieval agents `task-finder`/`git-historian`/`dependency-tracer`/`architecture-mapper` lower; reasoning agents `plan-critic`/`risk-assessor`/`contrarian-researcher`/`review-coordinator` stay high); (3) doc-truth model/effort updates; (4) document the effort-axis distinction. **Open (non-blocking):** profile-driven *dynamic* effort needs verification — per-spawn `effort` param is **unverified** (only `model` is documented per-spawn); dynamic would otherwise need env-var injection.

## S4 resolutions (W2 implementation — 2026-06-18)

S4 implemented the four scope items above. TDD: a failing test was written first for the resolver gate, then the fix; full suite green throughout.

- **Resolver MAJOR — FIXED.** `lib/profiles/phase-signal-resolver.mjs` now imports `BASE_ALLOWED_MODELS` from `profile-validator.mjs` and gates `model` (`if ('model' in entry && BASE_ALLOWED_MODELS.includes(entry.model))`), mirroring the `EFFORT_LEVELS` gate one line above. Out-of-allowlist models (e.g. `gpt-4`, `haiku`) are now dropped (treated as absent) instead of handed through to an agent spawn — defense-in-depth behind `brief-validator`'s validation-time check. 2 new tests in `tests/lib/phase-signal-resolver.test.mjs` (drops-invalid + keeps-valid). No circular import (`brief-validator` already imports the same symbol; `profile-validator` depends only on `util/`).
- **Native `effort:` — SHIPPED (static, additive).** Added `effort:` frontmatter to the 8 named agents: retrieval (`task-finder`, `git-historian`, `dependency-tracer`, `architecture-mapper`) → `medium`; adversarial-reasoning (`plan-critic`, `risk-assessor`, `contrarian-researcher`, `review-coordinator`) → `high`. The other 15 agents stay unset → inherit Opus-4.8 default (`high`). `claude plugin validate` passes (effort is a valid frontmatter field; only the pre-existing root-CLAUDE.md warning remains).
- **Doc-truth + axis distinction — DONE.** New canonical section `docs/profiles.md` §Model & effort axes (opus→Opus 4.8 default-`high`; orchestration `phase_signals.effort` vs native reasoning `effort:` table; native-effort precedence; which agents carry which level). Short note added to `CLAUDE.md` (after Agents table) and `README.md` (Cost profile section), both pointing to the profiles.md section.
- **Open (non-blocking, unchanged).** Only *static* per-agent effort shipped — the verified-safe minimum. Profile-driven *dynamic* effort still needs verification of the per-spawn `effort` param (only `model` is documented per-spawn) or env-var injection (`CLAUDE_CODE_EFFORT_LEVEL`). Deferred to W2 profile design.
- **Tests:** 582 total / 580 pass / 0 fail / 2 skip (was 578 pass; +2 new resolver tests).

## W1 — Orchestration architecture (multi-week, empirical)

| ID | Change (version) | Type | Voyage relevance | Decision | Rationale |
|----|------------------|------|------------------|----------|-----------|
| **CC-26** | Sub-agents spawn sub-agents ≤5 deep (**2.1.172**, verified) — the design response to CC-01 | NEW | Could restore *delegated* orchestration: an orchestrator sub-agent spawns the swarm; synthesis/writing delegated (the "missing summarizer link" in `docs/subagent-delegation-audit.md`). Frees main-context tokens | **EVALUATE → lean NO (S7)** | "Can spawn 5 deep" ≠ "Voyage's orchestrator→6-agent-swarm pattern performs well." **S7 (2026-06-18, GATE):** feasibility probed cheaply — depth-2 nesting works, no degradation; depth cap moot (Voyage needs depth 2); NEW finding = auto-mode proliferation classifier polices agent fan-out (risk unique to delegation). On cost/benefit, **wholesale delegation NOT recommended**; the only defensible path is a narrow opt-in synthesis-agent PoC, proven by Δ main-context tokens. Operator gates verdict. Full bake-off designed but NOT run. See `docs/T1-cc26-delegated-orchestration.md` + §S7. |
| **CC-27** | Dynamic Workflows / Workflow tool — orchestrates tens–hundreds of agents (**2.1.154**, verified); keyword `workflow`→`ultracode` (2.1.160); `agent()` attribution headers (2.1.174) | NEW | Voyage **hand-rolls** swarm/wave/pipeline orchestration in command prose — the Workflow tool is a native primitive for exactly this | **EVALUATE → selective hybrid (S8)** | The biggest identity decision: adopt Workflow as substrate, or stay prose-orchestrated? **S8 (2026-06-18, GATE):** probed cheaply — a minimal trekreview-shaped `parallel()`→`agent()` Workflow ran end-to-end (F1), structured schemas retire the JSON-parse fragility at `trekreview.md:202–204` (F2), result returns to main (F3), and a small purposeful fan-out did **not** trip the S7 proliferation classifier (F4). Reframe: "substrate swap" is a false binary — a `/trek*` command is ~80% non-orchestration glue, so Workflow can only ever replace the fan-out→synthesize *core* (hybrid). **Recommendation: selective hybrid, NOT wholesale swap** — tier 1 ship a prose schema contract (the F2 win, no Workflow dep); tier 2 port trekreview Phase 5–6 to a Workflow only if the designed bake-off shows fidelity-equivalent output + acceptable control/cost; tier 3 wholesale swap declined (portability floor 2.1.154+, opt-in UX, visibility loss). Operator gates verdict. Full bake-off designed, NOT run. See `docs/T2-cc27-workflow-substrate.md` + §S8. |
| **CC-28** | `TaskCreate` reliability — auto-repairs malformed input, schema in errors (2.1.163/169) | FIX | `TaskCreate`/`TaskUpdate` are in `trekplan`/orchestrator frontmatter but not actively used in command logic | **DEFER** | Becomes relevant only if W1 adopts task-graph orchestration. Tie to CC-26/27 outcome. |
| **CC-29** | `subagent_type` matching now case/separator-insensitive (2.1.140); multiple `Agent(...)` types in `tools:` no longer dropped (2.1.147); subagent transcript/backgrounding fixes (2.1.178) | FIX | improves DX of any delegated-orchestration design | **SHIP** (verify) | Free robustness. Confirm Voyage's agent `tools:` grants (none currently declare multiple `Agent(...)` types) and `subagent_type` references are unaffected. |
| **CC-31** | Worktree-isolation guard now applies in background sessions (2.1.154); `worktree.bgIsolation:"none"` (2.1.143); `EnterWorktree` switching mid-session (2.1.157) | CHANGE | `trekexecute` Phase 2.6 parallel waves + `trekplan` "execute with team" use git worktrees / `TeamCreate isolation:"worktree"` | **EVALUATE** | Verify Voyage's worktree-based parallel execution still behaves under the tightened bg-isolation guard. Affects the multi-session headless path. |

---

## S7 resolutions (W1 / CC-26 gate — 2026-06-18, operator-gated)

S7 was the first W1 gate. Operator chose a **staged** execution: cheap live feasibility probe +
measurement-design doc; the expensive head-to-head comparison was specified but **not run**.

- **Feasibility (measured).** A recursive `general-purpose` agent chain in this CC 2.1.181
  interactive session confirmed: depth-2 nesting works (`main → L1 → L2`; both children report the
  Agent tool available), and the nested sub-agent returned a real, well-formed result — **no silent
  degradation** at depth 2. The v2.4.0 premise ("harness does not expose Agent to sub-agents") is
  confirmed false at the interactive sub-agent level.
- **Depth cap moot.** The ≤5 cap was never reached; the recursion stopped at L2→L3 via the
  **auto-mode permission classifier** (policy denial: "uncontrolled agent proliferation"), not the
  nesting limit. Voyage's needed pattern is depth 2, so the cap does not bind this gate.
- **NEW finding — proliferation classifier.** Auto/bypass modes actively deny purposeless agent
  fan-out. A delegated orchestrator spawning a 6–10-agent swarm from inside a sub-agent under
  `auto`/`bypassPermissions` is exactly that shape — a classifier-interference risk **unique to
  delegation** that inline orchestration does not carry, and a new silent-degradation surface if a
  mid-pipeline spawn is denied. Must be in any future delegated-spawn test matrix.
- **CC-26 recommendation (operator gates verdict).** Lean **NO** on wholesale delegated
  orchestration: feasibility is no longer the blocker, so the gate turns on cost/benefit, which is
  unfavourable (delegation's only upside is main-context relief, against wall-time loss, context
  re-delivery cost, the audit's iteration/adversarial-review/debuggability tradeoffs, and the new
  classifier risk). The only defensible win is a **narrow opt-in synthesis-agent** (delegate just
  trekplan Phase 7's heaviest inline read), adopted only if a measured Δ main-context ≥ 30% with no
  quality loss materialises. CC-27 (Workflow tool, S8) is the more promising substrate question and
  is untouched.
- **Artifact.** `docs/T1-cc26-delegated-orchestration.md` — full gate evidence, the §5 full
  bake-off design (thresholds POSITIVE/NEGATIVE/INCONCLUSIVE), and the §6 synthesis-agent PoC, all
  ready to run if the operator greenlights pursuing delegation.

## S8 resolutions (W1 / CC-27 gate — 2026-06-18, operator-gated)

S8 was the second W1 gate — the orchestration-substrate identity decision. Operator chose the same
**staged** execution as S7: cheap live feasibility probe + measurement-design doc; the head-to-head
prose-vs-Workflow bake-off was specified but **not run**.

- **Feasibility (measured).** A minimal trekreview-shaped Workflow — `parallel([reviewerA,
  reviewerB])` with a findings schema → `agent(coordinator)` with a verdict schema, trivial agents,
  synthetic input — ran end-to-end in this CC 2.1.181 interactive session: both reviewers returned
  (F1), structured schemas delivered typed findings with no JSON-parse step (F2), the synthesizer
  reproduced Phase-6 dedup+verdict behavior and the result returned to main (F3), and the small
  purposeful fan-out did **not** trip the S7 proliferation classifier (F4). _3 agents · 85 461
  tokens · 13.8 s._
- **Reframe — "substrate swap" is a false binary.** A `/trek*` command is ~80% non-orchestration
  glue (mode parsing, triage, validators, stats, HTML) and ~20% agent fan-out. The Workflow tool
  can only ever replace the fan-out→synthesize *core* (trekreview Phase 5–6), so the real decision
  is a **scoped hybrid per core**, not a wholesale identity swap. (Mirrors S7's "wall-time is not
  the gate metric" reframe.)
- **The one concrete win is schema robustness (F2)** — and it is capturable *without* the Workflow
  tool: codify reviewer-output JSON as a validated prose schema contract, retiring the fragile
  "collect trailing JSON / re-ask on parse error" at `trekreview.md:202–204`.
- **CC-27 recommendation (operator gates verdict).** **Selective hybrid, NOT wholesale swap**, in
  three tiers: (1) ship a prose schema contract regardless — the F2 win, zero new dependency; (2)
  port trekreview Phase 5–6 to a Workflow *only if* the designed bake-off shows fidelity-equivalent
  output + acceptable control/cost — best-case first port; (3) wholesale substrate swap **declined**
  (portability floor 2.1.154+, opt-in/billing UX on every invocation, loss of mid-flow operator
  visibility for an operator-gated review tool). CC-26 (S7) and CC-27 (S8) are now both resolved to
  "narrow/selective, operator-gated, not wholesale."
- **Open risk inherited from S7.** Classifier behavior at *large* fan-out (trekplan's 6–10-agent
  swarm) under `auto`/`bypass` is still unverified — trekreview's 2–3 agents are below threshold,
  but a later trekplan port must measure it first.
- **Artifact.** `docs/T2-cc27-workflow-substrate.md` — full gate evidence (F0–F4), §5 bake-off
  design (thresholds POSITIVE/NEGATIVE/INCONCLUSIVE), §6 no-Workflow schema-contract PoC, all ready
  to run if the operator greenlights tier 1 and/or tier 2.

## Sequencing

```
Weekend (W0 + W4):  CC-01 doc-truth fix  ·  CC-06 plugin validate  ·  CC-02/CC-29 verify-no-regression
                    → ship something important AND correct.

Near-term (W2):     CC-21 + CC-22 effort/model alignment decision  → GATES v5.4 (per operator decision).
                    Resolves the resolver MAJOR finding in the same pass.

Then:               v5.4 brief-schema public contract  →  v5.5 brief framing enforcement.

Multi-week (W1):    CC-26 empirical sub-agent-nesting test  +  CC-27 Workflow-adoption prototype.
                    Outcome rewrites CC-01's "current design" statement and feeds the
                    docs/subagent-delegation-audit.md open problem.

Incremental (W3):   CC-11/CC-14/CC-15 as small, independently-shippable hardening PRs.
```

## Open questions (need operator or empirical answer)

1. **W1 identity:** does Voyage adopt the Workflow tool as substrate, or stay prose-orchestrated? (CC-27) — **S8: false binary; lean selective hybrid (port the fan-out→synthesize core only), NOT wholesale swap; see §S8.**
2. **W1 perf:** does delegated orchestration (orchestrator sub-agent → swarm) beat inline at Voyage's scale? (CC-26 — empirical) — **S7: feasibility YES, but lean NO on wholesale adoption; see §S7.**
3. **W2 effort model:** map `phase_signals` onto native `effort:`, or keep bespoke? (CC-22 — gates v5.4)
4. **CC-08:** is GH #36071 (hooks in headless) fixed? Determines whether the safety-preamble can relax.

## Empirical tests required

- **T1 (CC-26):** orchestrator-sub-agent spawns the planning swarm vs. inline baseline — wall-time, quality, token cost, depth-cap behavior. Harness: extend `scripts/q3-cache-prefix-experiment.mjs` pattern. — **S7: feasibility half RUN** (depth-2 works, no degradation, cap moot, proliferation-classifier risk found); **perf half DESIGNED, NOT run** (full bake-off + cheaper synthesis-agent PoC specified in `docs/T1-cc26-delegated-orchestration.md` §5/§6).
- **T2 (CC-27):** reimplement `/trekreview`'s reviewer swarm as a Workflow; compare control, cost, and output fidelity vs. prose orchestration. — **S8: feasibility RUN** (probe: core ports natively, schemas retire JSON fragility, small fan-out classifier-clean); **fidelity/control/cost bake-off DESIGNED, NOT run** (`docs/T2-cc27-workflow-substrate.md` §5/§6).
- **T3 (CC-04/CC-31):** research-agent MCP degradation under `--strict-mcp-config`; worktree parallel-wave behavior under tightened bg-isolation.

---

_Catalogue covers 31 evaluated changes (CC-01…CC-31; CC-18/19/20/30 folded into CC-17/CC-29 rows). Generated 2026-06-18 against Voyage v5.1.1 / CC 2.1.181._