Summary

Multi-role agent architecture deployed, fusion reactor project completed and sent to red-team review, new elevator control system project queued as the first system to run the full improved pipeline. This post also captures lessons from the fusion reactor stress test.

Fusion Reactor: Stress Test Assessment

The Fusion Reactor Control System was deliberately chosen as a stress test for the harness infrastructure. A tokamak reactor control system is among the most complex safety-critical systems conceivable — SIL 4 plasma control, cryogenic magnet protection, high-energy disruption mitigation, and nuclear regulatory compliance. It was selected to expose failure modes in the harness that simpler systems wouldn’t trigger.

What it exposed:

Problem	Sessions wasted	Root cause	Fix
QC loop (every session ran QC)	22 sessions (~$40)	SubstrateStateStore.get() returned wrong fact due to missing subject filter	Query with defaultSubject first
Homeless requirements (118/302)	Ongoing	QC flow lacked mandatory --document/--section instruction	Added mandatory flags to QC flow
Premature first-pass-complete	1 session	Claude set first-pass-complete on 28-req project	Deterministic guards replaced self-assessment
Session timeouts (exit 143)	3 sessions	20-min timeout too tight for 48KB prompt	Increased to 25 min
complete → idle bypass	2 sessions	Legacy code mapped complete to idle before flow selection	Removed backwards-compat mapping

What it validated:

• CCCS quality gates blocked premature transitions (unassignedDoc > 0 held the gate correctly)
• Hazard analysis produced 10+ hazards with SIL allocation
• Cross-domain search surfaced useful analogs (nuclear reactor protection, railway signalling)
• Tool call statistics tracked 50-100 calls per session
• LAST_SESSION_NEXT context passing worked — sessions referenced prior recommendations
• Quality blocker injection told Claude what to fix

Final state: 317 requirements, 373 trace links, 10 diagrams, 0 orphans, 0 homeless. Sent to red-team review (session 433, running on Opus).

Multi-Role Agent Architecture

Per-flow model, timeout, and protocol overrides deployed. Roles are metadata on flows — no new abstraction.

Flow	Role	Model	Timeout	Rationale
concept	Chief SE	opus	30 min	Deep reasoning for ConOps, hazard analysis
scaffold	Chief SE	opus	30 min	Functional analysis, architecture decisions
decompose	Systems Engineer	sonnet	25 min	Mechanical requirement creation
qc	Quality Engineer	sonnet	20 min	Metrics checking, lint
validate	Verification Engineer	sonnet	25 min	Test adequacy, scenario tracing
review	Chief SE	opus	30 min	Holistic coherence assessment
red-team	Red Team Analyst	opus	30 min	Adversarial analysis

Infrastructure supports per-flow protocol files (role-specific system prompts) — not yet created. Adding a new role = one YAML entry + one protocol .md file, zero harness code changes.

New Project: Industrial Elevator Control System

Queued as the first project to run the full improved pipeline:

1. Concept definition (Chief SE, Opus) — mission, ConOps with operating modes, hazard register per EN 81-20/50, SIL 3 for safety chain, stakeholder roleplay, environment
2. Scaffold (Chief SE, Opus) — stakeholder needs from ConOps, system requirements with SIL tags, functional analysis with UHT clustering, spec tree, subsystem decomposition
3. Decompose (Systems Engineer, Sonnet) — per-subsystem work driven by spec tree, canonical diagram names, locked section IDs
4. QC (Quality Engineer, Sonnet) — CCCS quality gates, per-subsystem completeness via spec tree
5. Validate (Verification Engineer, Sonnet) — V-model verification audit + ConOps scenario tracing + safety argument
6. Review (Chief SE, Opus) — acceptance assessment with per-subsystem summary and cross-domain insights
7. Red-team (Red Team Analyst, Opus) — 9 adversarial checks including safety integrity audit

The elevator is deliberately smaller (~5-6 subsystems, ~10-15 sessions) than fusion reactor (~8 subsystems, ~45 sessions) to validate the pipeline without the cost.

Additional Fixes

• Removed legacy complete → idle state mapping that bypassed red-team flow
• Session timeout increased from 20 to 25 minutes (prompt grew to 48KB with new sections)
• Quality gate blockers now injected into session prompt so Claude knows what to fix
• Previous session’s “Next” section passed forward as context

Version Manifest

Component	Before	After
Agent architecture	Single model (sonnet)	Per-flow roles (opus/sonnet by flow)
Concept → complete pipeline	6 flows	7 flows with roles
Session config	Global	Per-flow overrides
State mapping	complete → idle bypass	Direct complete state for red-team
Session context	None between sessions	LAST_SESSION_NEXT + QUALITY_BLOCKERS
Projects completed	1 (surgical robot)	2 (+fusion reactor)
Active project	Fusion reactor	Industrial Elevator Control System
Git commits	21	24