# Multi-agent SOLUTION_ERP — Master Coordination Guide

> **Architecture:** 3 sub-agents Opus 4.7 1M Max + em main coordinator.
> Pattern: Anthropic Building Effective Agents orchestrator-workers + Cognition "writes single-threaded" hybrid.
> Setup: Session 20 turn 12 (2026-05-11) — empirical-grounded từ NAMGROUP s41-s43 trial curve.

---

## 🎯 Architecture

```
┌─────────────────────────────────────────────────────────┐
│ EM (Main) — Opus 4.7 1M Max                             │
│ • Reasoning + write code (single-threaded principle)    │
│ • User dialog + architectural decisions                 │
│ • Coordinate 3 sub-agents via SendMessage               │
│ • Synthesize cross-agent findings end-of-session        │
└─────────────────────────────────────────────────────────┘
                ↓ spawn + keep-alive (Opus 4.7 1M Max each)
  ┌──────────────┐  ┌──────────────┐  ┌──────────────┐
  │ Investigator │  │  Implementer │  │   Reviewer   │
  │   READ only  │  │  WRITE strict│  │   READ only  │
  │              │  │ classification│  │              │
  │  Research +  │  │ Cookie-cutter│  │ Adversarial  │
  │   Audit +    │  │  + Multi-file│  │ pre-commit + │
  │   External   │  │  independent │  │ live verify  │
  │   research   │  │     ONLY     │  │              │
  └──────────────┘  └──────────────┘  └──────────────┘
        cyan             yellow              red
```

---

## 🔄 Invocation decision tree (em main apply)

Task input → classify task type:

```
├── Read-only research / audit / scan > 5 files / external fetch?
│     → Spawn Investigator (always safe)
│
├── Adversarial pre-commit verify / heavy diff / deploy claim?
│     → Spawn Reviewer (always before push critical)
│
├── Cookie-cutter mechanical (N independent files same pattern, deterministic spec)?
│     ✓ N >= 5 files
│     ✓ Spec deterministic (no implicit decisions)
│     ✓ Pattern proven > 1× prior
│     → Spawn Implementer (Case 1 Anthropic verified)
│
├── Multi-file independent changes (different modifications per file)?
│     ✓ Each file verifiable independently
│     ✓ Files NOT cross-stack tight coupling
│     → Spawn Implementer (Case 2 orchestrator-workers)
│
├── Test generation for isolated methods?
│     → Spawn Implementer (Case 3 verified)
│
├── Mass code migration (framework upgrade, per-file deterministic)?
│     → Spawn Implementer (Case 5 verified)
│
├── Quick task < 30 min (overhead spawn không xứng)?
│     → Em solo direct
│
├── Schema design / UX flow / architectural decision / cross-stack tight coupling?
│     → Em solo (Cognition "writes single-threaded")
│     → Investigator pre-flight optional
│     → Reviewer pre-commit always
│
└── Bug fix tightly coupled (cross BE/FE/DB, reasoning chain)?
      → Em solo (Anthropic warning: "tightly interdependent coding")
      → Investigator pre-flight optional
      → Reviewer pre-commit always
```

---

## 📋 Implementer task classification — CRITICAL rules

**Em main MUST self-check before spawning Implementer:**

### ✅ ACCEPT criteria (ALL must be true)
1. ✅ Spec deterministic (no implicit decisions left for agent)
2. ✅ Files independent (modifications don't depend on each other)
3. ✅ Pattern repeatable (proven > 1× prior session — reference memory entries)
4. ✅ Estimated effort > 30 min (overhead worth)
5. ✅ Max 2 layers cross-stack (NOT BE entity + DTO + FE wire 3-layer)
6. ✅ Each file output verifiable independently

### ❌ REFUSE criteria (ANY triggers refusal)
1. ❌ Schema design decisions needed
2. ❌ UX flow decisions needed
3. ❌ Cross-stack > 2 layers tight coupling
4. ❌ Bug fix involving reasoning chain
5. ❌ Integration testing involving multiple components
6. ❌ < 30 min trivial task
7. ❌ First time pattern (no prior precedent)
8. ❌ Spec ambiguity > 20%

**Implementer agent ALSO has self-check trong system prompt → auto-refuse out-of-scope.**

---

## 💾 Memory consult discipline

Each agent has `.claude/agent-memory/<name>/MEMORY.md` persistent diary:

- **Spawn:** Auto-inject first 200 lines / 25KB của MEMORY.md
- **During work:** Agent may Read full MEMORY.md if task complex
- **Before return:** Agent MUST update MEMORY.md với findings (BẮT BUỘC)
- **Cross-session:** MEMORY.md persists on disk

**Em main routine end-of-session:**

```
SendMessage Investigator: "Flush MEMORY.md với findings session này. Format:
  1-2 sentences per finding. Categories: patterns / anti-patterns / gotchas
  discovered / external research summary."

SendMessage Implementer: "Flush MEMORY.md với patterns applied + ambiguities
  encountered + scope refusals."

SendMessage Reviewer: "Flush MEMORY.md với anti-patterns observed + gotcha
  regressions caught + claim verification results."

Em read 3 MEMORY.md updates → synthesize cross-agent learnings → integrate
  vào project memory / session log.

Em proceed normal close-out: STATUS update + commit + push.
```

---

## 🛠️ SendMessage discipline

**Cost optimization:**
- Within 5min cache TTL window khi possible (90% discount cached prefix)
- Compact prompts (~5K new content each) thay vì dump (~24K)
- Skip spawn cho task < 30min

**Context discovery preservation:**
- Include explicit "Include surprising findings + edge cases discovered" trong spec
- Periodic checkpoint mỗi 1-2h heavy work: prompt agents flush MEMORY.md
- Session crash → MEMORY.md preserved on disk, in-session context lost

---

## 🎯 Project-specific tunings (SOLUTION_ERP)

**Stack:** .NET 10 Clean Architecture + CQRS MediatR + EF Core 10 + SQL Server + 2 React 19 Vite 8 FE (admin + user) + Gitea Actions CI + Windows IIS.

**Current state (Session 20 turn 12):** 27 migrations · 59 DB tables · ~142 endpoints · 34 FE pages · 81 test pass · 44 gotchas · 14 memory entries · 6 skills · 30 demo user · 3 prod domain `*.solutions.com.vn`.

**Skills preload mỗi sub-agent:**
- **Investigator:** `contract-workflow` + `permission-matrix` + `ef-core-migration` (research patterns + schema audit)
- **Implementer:** `ef-core-migration` + `permission-matrix` + `form-engine` (scaffold + 3-file rule + permission seed)
- **Reviewer:** `dependency-audit-erp` + `iis-deploy-runbook` + `contract-workflow` (security/deploy/workflow audit)

**Context paste session start (em main responsibility):**
- `docs/STATUS.md` current state
- `docs/CLAUDE.md` root tech context
- Latest 2 session logs `docs/changelog/sessions/`
- Active gotchas `docs/gotchas.md`
- Memory entries `C:\Users\pqhuy\.claude\projects\D--Dropbox-CONG-VIEC-SOLUTION\memory\MEMORY.md`

→ Auto-inject baseline ~80-150K per agent. Plus task-specific Read on-demand.

**Windows MAX_PATH pitfall:** Project path `D:\Dropbox\CONG_VIEC\SOLUTION\SOLUTION_ERP\` đã nested 51 chars + Dropbox-managed. **Implementer frontmatter KHÔNG dùng `isolation: worktree`** (per Pitfall 1 template). Default branch isolation OK.

**UAT live mode (Phase 9 active):** Memory `feedback_uat_skip_verify` — skip `dotnet test` mỗi chunk, vẫn `npm run build` × 2 app. Reviewer khi spawn pre-commit cần áp rule này (không yêu cầu test increment cho UAT iteration), VẪN verify wire BE + security + anti-fiddle.

---

## 📊 Cost reality

| Component | Effective tokens billed (after caching) |
|---|---|
| 3 sub-agents spawn setup | ~564K (3 × 188K cache WRITE) |
| 10 SendMessages each ~24K new | ~450K (10 × 45K equivalent với cache READ) |
| Em main session | ~200K |
| **Total per heavy session** | **~1.2M (~6× solo)** |
| **Optimized (compact + cache + skip trivial)** | **~600K (~3× solo)** |

**Max 20× plan absorbs ~3× solo cost comfortable.**

---

## 🧪 Trial workflow (2-4 tuần evaluate)

- **Week 1:** Setup + Plan trial cookie-cutter (Case 1 verified). SOLUTION_ERP candidate: Contract V2 wire Mig 28+29 mirror PE pattern — pattern proven 1× S17-S19 (PE V2). ~600+ LOC, 2 mig + Service + Controller + FE × 2 app.
- **Week 2-3:** Feature wire (Solo em + Inv pre-flight + Rev pre-commit) — phân quyền strict V2 + drop legacy V1.
- **Week 4:** Evaluate quality vs cost real numbers.
  - Pass criteria: Rev catch ≥ 2 wire bugs trước commit + time saving ≥ 25% Case 1+2 + Max 20× quota comfortable
  - Fail criteria: any of above unmet → rollback solo, agents archived

---

## 🔗 References

- [Anthropic Building Effective Agents](https://www.anthropic.com/engineering/building-effective-agents)
- [Cognition "Multi-Agents Working"](https://cognition.ai/blog/dont-build-multi-agents)
- [Anthropic Sub-agents docs](https://docs.claude.com/en/docs/claude-code/sub-agents)
- Memory entries (`C:\Users\pqhuy\.claude\projects\D--Dropbox-CONG-VIEC-SOLUTION\memory\`):
  - `feedback_per_chunk_commit.md` — per-chunk discipline reference cho Implementer pattern
  - `feedback_uat_skip_verify.md` — Reviewer rule trong Phase 9
  - `feedback_drastic_refactor_scope.md` — Implementer refuse criteria reference
  - `feedback_audit_reuse_before_clone.md` — Investigator audit-first pattern