# Phase 2 Implementation Plan: The Steward

**Status**: Active Planning  
**Created**: 2025-12-07  
**Estimated Duration**: 4-5 weeks  
**Goal**: Implement first-tier request analysis and household capability coordination

---

## Executive Summary

Phase 2 introduces **The Steward** - a first-tier LLM agent that analyzes incoming requests, identifies relevant household capabilities, and provides focused recommendations to Tatlock (the Butler). This creates a two-tier architecture that prevents cognitive overload and enables efficient tool/agent coordination.

### Key Deliverables

1. **Household Registry**: Centralized capability catalog with PydanticAI Toolsets
2. **Steward Agent**: Request analyzer with conversation context awareness  
3. **Tool Scoping**: Dynamic toolset creation based on recommendations
4. **Observability**: Performance benchmarking and tool usage tracking via Redis
5. **Integration**: Full Steward → Tatlock request flow

---

## Core Architectural Principles

### 1. Household-Based Organization
- Each expert agent owns their tools in a domain directory
- Tools organized as functional clusters around capabilities
- Example: `src/agents/tatlock_core/` contains calculator, datetime, web search

### 2. Two-Tier Capability Abstraction
- **Executive Summary**: High-level capabilities for Steward/Butler coordination
- **Implementation Details**: Full tool specifications for household members
- Steward sees summaries, household members see full details

### 3. PydanticAI Native Patterns
- Use `FunctionToolset` and `CombinedToolset` for composition
- Decorator-based tool registration (`@agent.tool`)
- Structured outputs via Pydantic models
- Agent delegation pattern for expert agents (Phase 4)

### 4. Separate Registries
- **Household Registry**: Tools + capabilities (new in Phase 2)
- **Model Registry**: Agents/models (existing from Phase 1)
- Clean separation of concerns

### 5. Start Minimal
- Only 3 core Tatlock tools initially: calculator, datetime, web search
- No new tools until expert agents exist (Phase 4)
- Prove the pattern before expanding

---

## Implementation Milestones


### Milestone 1: Household Registry + Logging Infrastructure (Week 1-2)

#### Goal
Create a registry system that aggregates household capabilities using PydanticAI Toolsets and establish observability infrastructure.

#### Tasks

**1.1 Create Household Registry Module**

Location: `src/core/household_registry.py`

```python
from pydantic import BaseModel
from pydantic_ai import FunctionToolset, CombinedToolset

class HouseholdCapability(BaseModel):
    """Executive summary of a household member's capabilities."""
    name: str  # "tatlock_core", "librarian", "developer"
    role: str  # "Butler's Core Tools", "The Librarian"
    category: str  # "core", "research", "technical"
    description: str  # One-sentence description
    domains: list[str]  # ["computation", "information", "datetime"]
    cost: str  # "low", "medium", "high"
    requires_network: bool

class HouseholdMember(BaseModel):
    """Full specification of a household member."""
    capability: HouseholdCapability
    toolset: FunctionToolset
    agent: Agent | None = None  # For expert agents in Phase 4

class HouseholdRegistry:
    """Registry of household capabilities and implementations."""
    
    def __init__(self):
        self._members: dict[str, HouseholdMember] = {}
    
    def register(
        self,
        name: str,
        capability: HouseholdCapability,
        toolset: FunctionToolset,
        agent: Agent | None = None
    ):
        """Register a household member."""
        self._members[name] = HouseholdMember(
            capability=capability,
            toolset=toolset,
            agent=agent
        )
    
    def get_all_capabilities(self) -> list[HouseholdCapability]:
        """Get executive summaries for Steward/Butler."""
        return [m.capability for m in self._members.values()]
    
    def get_scoped_toolset(self, names: list[str]) -> CombinedToolset:
        """Create combined toolset from recommended capabilities."""
        toolsets = [self._members[name].toolset for name in names]
        return CombinedToolset(toolsets)

# Global registry instance
household_registry = HouseholdRegistry()
```


**1.2 Reorganize Tatlock Core Tools**

Create domain-based organization:

```
src/agents/tatlock_core/
├── __init__.py
├── tools.py          # Tool implementations (moved from src/agents/tools.py)
├── toolset.py        # PydanticAI toolset registration  
└── capability.py     # Executive summary for registry
```

**1.3 Create Logging Infrastructure**

Location: `src/core/logging_config.py`

- Structured logging with `structlog`
- JSON format for machine parsing
- Operation timing and metadata tracking
- Context manager for automatic timing

**1.4 Create Redis Benchmark Storage**

Location: `src/core/benchmarks.py`

Features:
- Performance benchmark recording (Steward analysis, tool calls)
- Cross-session persistence via Redis
- Time-series storage with automatic expiry (30 days)
- Queryable metrics for analysis

Benchmark schema:
```python
class PerformanceBenchmark(BaseModel):
    timestamp: datetime
    operation: str  # "steward_analysis", "tool_call"
    duration_seconds: float
    success: bool
    
    # Steward-specific
    recommendation_count: Optional[int]
    confidence: Optional[float]
    
    # Tool-specific
    tool_name: Optional[str]
    was_recommended: Optional[bool]
    was_actually_used: Optional[bool]
    
    # Context
    conversation_id: Optional[str]
    metadata: dict
```

**1.5 Testing**

- Test household registry registration and retrieval
- Test Toolset composition
- Test benchmark recording to Redis
- Test structured logging output

#### Success Criteria
- ✅ Household registry operational
- ✅ Tatlock core tools organized in domain directory
- ✅ Redis benchmarks working
- ✅ Structured logging functional
- ✅ Tests pass and maintain 80%+ coverage

---


### Milestone 2: Minimal Steward Agent with Context Analysis (Week 3-4)

#### Goal
Create a Steward agent that analyzes requests with full conversation context and recommends relevant household capabilities.

#### Tasks

**2.1 Create Steward Agent**

Location: `src/agents/steward/agent.py`

Structured output schema:
```python
class ConversationContext(BaseModel):
    """Contextual information from conversation history."""
    has_previous_context: bool
    relevant_turns: list[int]  # 0-indexed turn numbers
    context_summary: str  # Summary for Butler

class StewardRecommendation(BaseModel):
    """Structured recommendation from Steward analysis."""
    recommended_capabilities: list[str]
    reasoning: str
    estimated_complexity: Literal["simple", "moderate", "complex"]
    conversation_context: ConversationContext
    missing_capabilities: Optional[str] = None
```

Key features:
- Uses same model as Tatlock (`ollama:mistral-nemo`) for VRAM efficiency
- Receives FULL conversation history
- Queries household registry via tool
- Conservative recommendations (avoid over-inclusion)
- Explicit handling of missing capabilities

**2.2 Steward System Prompt**

Responsibilities:
1. **Capability Recommendation**: Query registry, recommend only necessary tools
2. **Conversation Analysis**: Identify references to previous topics
3. **Complexity Assessment**: Simple/moderate/complex classification
4. **Missing Capability Detection**: Suggest what's needed if no tools available

**2.3 Steward Service Layer with Logging**

Location: `src/agents/steward/service.py`

```python
async def analyze_request(
    user_request: str,
    conversation_history: list[dict]  # FULL conversation
) -> StewardRecommendation:
    """Analyze request with full conversation context."""
    
    async with log_operation("steward_analysis", {...}) as log_ctx:
        result = await steward_agent.run(
            user_request,
            message_history=convert_to_pydantic_history(conversation_history),
            usage_limits=UsageLimits(request_limit=3)
        )
        
        # Log and benchmark
        log_ctx["recommendation_count"] = len(result.data.recommended_capabilities)
        await benchmark_store.record(...)
        
        return result.data
```

**2.4 Testing**

Test scenarios:
- Calculator request → recommends tatlock_core
- Simple greeting → recommends []
- Web search request → recommends tatlock_core
- Request referencing previous turn → identifies context
- Impossible request → returns missing_capabilities

#### Success Criteria
- ✅ Steward queries household registry successfully
- ✅ Produces structured recommendations
- ✅ Analyzes full conversation context
- ✅ Handles missing capabilities gracefully
- ✅ Conservative recommendations (> 90% accuracy)
- ✅ Benchmarks recorded to Redis

---


### Milestone 3: Request Preprocessing & Tool Tracking (Week 5-6)

#### Goal
Wire Steward into request flow, implement tool scoping, and track tool usage.

#### Tasks

**3.1 Create Preprocessing Pipeline**

Location: `src/core/preprocessing.py`

```python
@dataclass
class EnrichedRequest:
    """Request enriched with Steward's analysis."""
    original_request: str
    steward_note: str  # Formatted note for Tatlock
    scoped_toolset: CombinedToolset  # Only recommended tools
    recommendation: StewardRecommendation
    steward_reasoning_output: str  # For streaming to user

async def preprocess_request(
    user_request: str,
    conversation_history: list[dict]  # FULL conversation
) -> EnrichedRequest:
    """Analyze via Steward and prepare scoped context."""
    # Call Steward with full conversation
    recommendation = await analyze_request(user_request, conversation_history)
    
    # Format note to Tatlock (includes conversation context)
    steward_note = format_steward_note(recommendation)
    
    # Create scoped toolset
    scoped_toolset = household_registry.get_scoped_toolset(
        recommendation.recommended_capabilities
    )
    
    return EnrichedRequest(...)
```

Note formatting:
- Includes conversation context summary
- Highlights missing capabilities if applicable
- Provides complexity estimate

**3.2 Tool Usage Tracking**

Location: `src/core/tool_tracking.py`

```python
class ToolCallTracker:
    """Tracks tool calls for benchmarking."""
    
    def __init__(self, recommended_tools: list[str]):
        self.recommended_tools = set(recommended_tools)
        self.actual_calls: dict[str, list[float]] = {}
    
    async def track_call(self, tool_name: str, duration: float):
        """Record a tool call with timing."""
        # Log if tool wasn't recommended
        if tool_name not in self.recommended_tools:
            logger.warning("tool_call_not_recommended", ...)
        
        # Record benchmark to Redis
        await benchmark_store.record(...)
    
    async def finalize(self):
        """Log unused recommended tools."""
        unused = self.recommended_tools - set(self.actual_calls.keys())
        # Record benchmarks for unused tools
```

**3.3 Integrate with Responses API**

Modify `src/responses/service.py`:
```python
async def generate_response(request: ResponseRequest) -> ResponseOutput:
    # Preprocess via Steward (with full conversation)
    enriched = await preprocess_request(
        user_message,
        conversation_history=request.input[:-1]
    )
    
    # Run Tatlock with scoped tools and tracker
    result = await run_tatlock_with_scoped_tools(
        enriched.original_request,
        enriched.steward_note,
        enriched.scoped_toolset,
        enriched.recommendation.recommended_capabilities,  # For tracking
        message_history,
        usage_tracker
    )
    
    # Build response with Steward reasoning
    return build_response_with_steward_reasoning(...)
```

**3.4 Update Tatlock Agent**

Location: `src/agents/tatlock.py`

```python
async def run_tatlock_with_scoped_tools(
    user_request: str,
    steward_note: str,
    scoped_toolset: CombinedToolset,
    recommended_tools: list[str],
    message_history: list[dict],
    usage: UsageeLimits
):
    # Initialize tracker
    tracker = ToolCallTracker(recommended_tools)
    
    # Prepend Steward's note (invisible to user, visible to Tatlock)
    enriched_prompt = f"{steward_note}\n\n{user_request}"
    
    # Run with ONLY scoped tools
    result = await tatlock_agent.run(
        enriched_prompt,
        message_history=convert_to_pydantic_history(message_history),
        toolsets=[scoped_toolset],  # Tool scoping enforced
        deps=tracker,  # For tracking
        usage=usage
    )
    
    # Finalize tracking
    await tracker.finalize()
    
    return result
```

**3.5 Add Streaming Transparency**

Modify `src/responses/streaming.py`:
- Stream Steward's reasoning first
- Then stream Tatlock's response
- Include conversation context notes
- Format missing capabilities warnings

**3.6 Testing**

Integration tests:
- Full Steward → Tatlock flow
- Tool scoping enforcement (can't use non-recommended tools)
- Tool usage tracking (recommended vs. actual)
- Conversation context propagation
- Missing capabilities handling

#### Success Criteria
- ✅ Full request flow working (User → Steward → Tatlock)
- ✅ Steward reasoning visible in output stream
- ✅ Tool scoping enforced (only recommended tools available)
- ✅ Tool usage tracked and logged to Redis
- ✅ Conversation context passed through pipeline
- ✅ Integration tests pass end-to-end

---


### Milestone 4: Testing, Benchmarking & Refinement (Week 7)

#### Goal
Validate the system, optimize performance, refine prompts, and establish monitoring.

#### Tasks

**4.1 Comprehensive Testing**

Test categories:
- End-to-end integration tests (full request flow)
- Performance benchmarks (latency targets)
- Prompt refinement (recommendation accuracy)
- Edge cases (errors, timeouts, missing capabilities)
- Conversation context accuracy

**4.2 Performance Validation**

Targets:
- Steward analysis: < 2 seconds
- Total added latency: < 3 seconds
- Model stays hot in VRAM (no reload delays)
- Tool recommendation accuracy: > 90%

**4.3 Benchmark Analysis Tools**

Create `scripts/benchmark_analysis.py`:

```bash
# View Steward performance over last 24 hours
python scripts/benchmark_analysis.py --operation steward_analysis --hours 24

# Analyze tool recommendation accuracy
python scripts/benchmark_analysis.py --tool-accuracy --days 7
```

Metrics to track:
- Average Steward analysis time
- Recommendation count distribution
- Tool accuracy (recommended & used, recommended but unused, not recommended but used)
- Recommendation precision percentage

**4.4 Prompt Engineering**

Iterate on Steward system prompt:
- Test with diverse request types
- Tune conservativeness (balance false positives/negatives)
- Validate conversation context analysis
- Test missing capability detection

**4.5 Documentation**

Update documentation:
- README.md: Steward explanation and examples
- AGENTS.md: Household registration pattern
- IMPLEMENTATION_ROADMAP.md: Mark Phase 2 complete
- Add benchmark analysis guide

#### Success Criteria
- ✅ < 3 seconds added latency for Steward analysis
- ✅ > 90% recommendation accuracy (manual evaluation)
- ✅ All integration tests pass
- ✅ Benchmark tools functional
- ✅ Documentation complete and accurate
- ✅ Ready for Phase 3/4 (expert agents)

---

## Architecture Diagram

```
User Request
    ↓
Orchestrator (FastAPI)
    ↓
Preprocessing Pipeline
    ├─→ Steward Agent
    │   ├─ Receives: FULL conversation history
    │   ├─ Analyzes: Context, references, requirements
    │   ├─ Queries: Household registry (capabilities)
    │   ├─ Outputs: StewardRecommendation
    │   │   ├─ recommended_capabilities: list[str]
    │   │   ├─ conversation_context: ConversationContext
    │   │   ├─ missing_capabilities: str | None
    │   │   └─ reasoning: str
    │   └─ Logs: Performance benchmarks → Redis
    │
    ├─→ Create Scoped Toolset
    │   └─ CombinedToolset from recommended capabilities
    │
    └─→ Format Steward Note
        └─ Includes conversation context for Tatlock
    ↓
Tatlock Agent (with scoped tools)
    ├─ Receives: Enriched request + Steward note
    ├─ Has access to: ONLY recommended tools
    ├─ Tool calls tracked: ToolCallTracker
    └─ Logs: Tool usage benchmarks → Redis
    ↓
Response to User
    ├─ Steward's reasoning (streamed first)
    └─ Tatlock's response (streamed second)

Background:
    └─ Redis: Performance benchmarks, tool usage analysis
```

---

## Design Decisions Summary

### 1. Logging & Performance Benchmarks
**Decision**: Full observability with Redis-backed benchmark storage

**Rationale**:
- Track Steward recommendations vs. Tatlock's actual tool usage
- Measure performance metrics (latency, token usage)
- Cross-session analysis for optimization
- Identify recommendation accuracy over time

### 2. Steward Fallback Behavior
**Decision**: Explicit missing capability communication

**Rationale**:
- No suitable tools → Steward states "missing capabilities" with description
- Can suggest what type of tool would be helpful
- Code errors → standard exception handlers (don't suppress real errors)
- Better UX than silent failures or defaulting to all tools

### 3. Conversation History for Steward
**Decision**: Steward sees FULL conversation, not just current turn

**Rationale**:
- Can identify references to previous topics
- Provides contextual notes to Butler
- "Two sets of eyes" on conversation
- Example: "User mentioned Python debugging in turn 3, relevant details: async code"

### 4. Registry Pattern
**Decision**: Separate Household Registry from Model Registry

**Rationale**:
- Tools belong to household members, not models
- Clean separation of concerns
- Executive summaries for coordination, details for execution

### 5. Tool Composition
**Decision**: PydanticAI FunctionToolset + CombinedToolset

**Rationale**:
- Native PydanticAI pattern
- Clean composition and filtering
- Dynamic scoping per request

### 6. Tool Scoping  
**Decision**: Compile-time scoping via toolset creation

**Rationale**:
- Tools not even visible to LLM
- Cleaner than runtime permission checks
- Enforced at PydanticAI level

### 7. Organization
**Decision**: Domain-based household directories

**Rationale**:
- Each household member owns their tools
- Clear bounded contexts
- Example: `src/agents/tatlock_core/`, `src/agents/librarian/` (future)

---

## Infrastructure Requirements

### Redis Setup

Development (quick start):
```bash
# Docker (recommended)
docker run -d -p 6379:6379 --name tatlock-redis redis:7-alpine

# Or local installation
# macOS: brew install redis && brew services start redis
# Linux: sudo apt install redis-server && sudo systemctl start redis
```

Production (docker-compose.yml):
```yaml
services:
  redis:
    image: redis:7-alpine
    ports:
      - "6379:6379"
    volumes:
      - redis_data:/data
    command: redis-server --appendonly yes

volumes:
  redis_data:
```

### Dependencies Update

Add to `requirements.txt`:
```txt
redis[hiredis]>=5.0.0,<6.0.0
structlog>=24.1.0,<25.0.0
```

### Configuration

Add to `.env`:
```env
# Redis Configuration
REDIS_URL=redis://localhost:6379/1

# Logging
LOG_LEVEL=INFO
LOG_FORMAT=json
ENABLE_BENCHMARKS=true
```

---

## Timeline

**Week 1-2**: Household Registry + Logging Infrastructure
- Household registry with Toolsets
- Structured logging with structlog
- Redis benchmark storage
- Tatlock core reorganization
- Tests: Registry + benchmarking

**Week 3-4**: Steward Agent with Context Analysis
- Steward agent with conversation context
- ConversationContext in recommendations
- Missing capabilities handling
- Tests: Context analysis, missing capabilities

**Week 5-6**: Integration + Tool Tracking
- Request preprocessing with full conversation
- Tool usage tracking middleware
- Scoped toolset creation
- Streaming transparency
- Tests: Full flow + tool tracking

**Week 7**: Testing, Benchmarking & Refinement
- End-to-end integration tests
- Benchmark analysis tools
- Prompt refinement
- Performance validation
- Documentation updates

**Total: 4-5 weeks** (core implementation complete in 6 weeks, polish in week 7)

---

## Success Metrics

### Technical
- ✅ Household registry operational with executive summaries
- ✅ Steward produces accurate recommendations (> 90%)
- ✅ Steward analyzes full conversation context
- ✅ Tool scoping enforced (Tatlock can't use non-recommended tools)
- ✅ Model efficiency preserved (no reload delays)
- ✅ Added latency < 3 seconds
- ✅ Performance benchmarks recorded to Redis
- ✅ Tool usage tracking (recommended vs. actual)

### Observability
- ✅ Structured logging (JSON format)
- ✅ Benchmark analysis tools available
- ✅ Tool recommendation accuracy measurable
- ✅ Cross-session performance trends visible

### Error Handling
- ✅ Missing capabilities explicitly communicated
- ✅ Steward can guide user toward needed resources
- ✅ Code errors properly surfaced (not suppressed)

### Architectural
- ✅ PydanticAI patterns followed (Toolsets, decorators, structured outputs)
- ✅ Clean separation: registry vs. agents vs. tools
- ✅ Two-tier abstraction working (summaries vs. details)
- ✅ Future-proof for expert agents (Phase 4)

### Testing
- ✅ Maintain 80%+ test coverage
- ✅ Integration tests for full flow
- ✅ Performance benchmarks established

---

## Future-Proofing for Phase 4

### Expert Agent Pattern (Template)

When adding The Librarian, The Developer, etc., follow this structure:

```
src/agents/librarian/
├── __init__.py
├── agent.py          # Librarian PydanticAI agent
├── tools.py          # Librarian-specific tools (wiki, research, etc.)
├── toolset.py        # PydanticAI toolset creation
└── capability.py     # Executive summary for registry
```

Example capability registration:
```python
# capability.py
LIBRARIAN_CAPABILITY = HouseholdCapability(
    name="librarian",
    role="The Librarian",
    category="research",
    description="Research assistance, knowledge management, and information synthesis",
    domains=["research", "knowledge_base", "documentation"],
    cost="medium",
    requires_network=True
)

def register_librarian():
    household_registry.register(
        name="librarian",
        capability=LIBRARIAN_CAPABILITY,
        toolset=librarian_toolset,
        agent=librarian_agent  # Expert agent for delegation
    )
```

Tatlock delegation pattern (Phase 4):
```python
@tatlock_agent.tool
async def consult_librarian(
    ctx: RunContext[None],
    research_query: str
) -> str:
    """Consult the Librarian for research assistance."""
    from src.agents.librarian.agent import librarian_agent
    
    result = await librarian_agent.run(
        research_query,
        usage=ctx.usage  # Aggregate usage
    )
    return result.data
```

---

## Risk Mitigation

### Identified Risks

1. **Steward recommendations too broad**
   - Mitigation: Conservative prompt engineering, benchmark tracking, iterate based on false positives

2. **Added latency unacceptable**
   - Mitigation: Stream Steward reasoning for transparency, optimize prompt, use same base model

3. **Tool registry becomes unwieldy**
   - Mitigation: Good categorization, semantic search (future), regular pruning

4. **Model VRAM competition**
   - Mitigation: Use same base model for Steward and Tatlock, sequential calls

5. **Redis dependency**
   - Mitigation: Make benchmarking optional, graceful degradation if Redis unavailable

---

## Open Questions - RESOLVED

All major design questions have been resolved. See "Design Decisions Summary" section above.

---

## Next Steps

### Immediate (Today/This Week)
1. Set up Redis (Docker or local)
2. Create `src/core/logging_config.py` with structured logging
3. Create `src/core/benchmarks.py` with Redis storage
4. Add `redis` and `structlog` to requirements.txt
5. Create household registry skeleton

### Week 1-2
1. Complete household registry with Toolset integration
2. Reorganize Tatlock core tools into domain directory
3. Implement logging infrastructure
4. Write tests for registry + benchmarking

### Week 3-4
1. Create Steward agent with conversation context
2. Implement missing capabilities handling
3. Test context analysis accuracy
4. Iterate on system prompt

### Week 5-6
1. Build preprocessing pipeline
2. Integrate with Responses API
3. Implement tool tracking
4. Add streaming transparency

### Week 7
1. End-to-end testing
2. Benchmark analysis
3. Performance optimization
4. Documentation updates

---

## Document Status

**Status**: Active Planning Document  
**Created**: 2025-12-07  
**Last Updated**: 2025-12-07  
**Version**: 1.0  
**Next Review**: After Milestone 1 completion

---

**Reference Documents**:
- [PHILOSOPHY.md](PHILOSOPHY.md) - System vision and architecture
- [IMPLEMENTATION_ROADMAP.md](IMPLEMENTATION_ROADMAP.md) - Full project roadmap
- [AGENTS.md](AGENTS.md) - Agent development guidelines
- [README.md](README.md) - User documentation