> ## Documentation Index
> Fetch the complete documentation index at: https://docs.metacogna.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Agent API

> Specialized agent workers API

Parti Architecture uses 7 specialized agent workers, each responsible for a specific phase of software architecture generation.

## Agent Workers

### PRD Agent

**Worker**: `parti-prd-agent`

Generates Product Requirements Documents from product seeds.

**Input**: Product seed description
**Output**: Comprehensive PRD with user personas, functional requirements, roadmap

**System Prompt Focus:**

* Executive summary
* User personas
* Functional requirements
* Non-functional requirements
* MoSCoW roadmap (Must/Should/Could/Won't Have)

### Data Agent

**Worker**: `parti-data-agent`

Creates data models and database schemas.

**Input**: PRD and requirements
**Output**: Entity-relationship models, database schemas, migration scripts

**System Prompt Focus:**

* Entity identification
* Relationship modeling
* Database schema design
* Migration strategies

### Design Agent

**Worker**: `parti-design-agent`

Designs UI/UX systems and design tokens.

**Input**: PRD and data models
**Output**: Design system, color tokens, typography, component specs

**System Prompt Focus:**

* Design tokens (colors, typography, spacing)
* Component library structure
* UI/UX patterns
* Accessibility guidelines

### Logic Agent

**Worker**: `parti-logic-agent`

Defines business logic and workflows.

**Input**: PRD, data models, design system
**Output**: Business rules, state machines, validation logic, workflows

**System Prompt Focus:**

* Business rules
* State machines
* Validation rules
* Error handling
* **Triggers HITL interrupt** after completion

### API Agent

**Worker**: `parti-api-agent`

Designs REST/GraphQL API specifications.

**Input**: PRD, data models, business logic
**Output**: API endpoints, request/response schemas, OpenAPI specification

**System Prompt Focus:**

* RESTful API design
* Resource modeling
* Request/response schemas
* Authentication/authorization
* Rate limiting
* Error handling

### Frontend Agent

**Worker**: `parti-frontend-agent`

Architects React frontend systems.

**Input**: PRD, design system, API specification
**Output**: Component hierarchy, state management, routing, build configuration

**System Prompt Focus:**

* Component architecture
* State management (Zustand/Redux)
* Routing structure
* Data fetching patterns
* Performance optimization
* Accessibility

### Deployment Agent

**Worker**: `parti-deployment-agent`

Creates infrastructure and CI/CD pipelines.

**Input**: API specification, frontend architecture, overall system
**Output**: Infrastructure as Code, CI/CD pipelines, deployment configs

**System Prompt Focus:**

* Cloudflare Workers/Pages configuration
* CI/CD pipelines (GitHub Actions)
* Database migrations
* Monitoring and observability
* Security configuration
* Disaster recovery

## Agent Communication

Agents communicate via Cloudflare service bindings:

```typescript theme={null}
// Supervisor calls agent
const response = await env.PRD_AGENT.fetch(request);

// Agent receives request
export default {
  async fetch(request: Request, env: Env): Promise<Response> {
    // Process request and generate artifact
    return new Response(JSON.stringify(artifact));
  }
};
```

## Agent Request Format

All agents receive requests with this structure:

```json theme={null}
{
  "system_state": {
    "current_phase": "prd",
    "project_id": "project-uuid"
  },
  "context": "Previous artifacts and context...",
  "user_input": "Product description..."
}
```

## Agent Response Format

All agents return responses in this format:

```json theme={null}
{
  "system_state": {
    "current_phase": "prd",
    "status": "complete",
    "interrupt_signal": false
  },
  "artifact": {
    "type": "markdown",
    "content": "# Product Requirements..."
  },
  "trace": {
    "agent": "prd-agent",
    "timestamp": "2024-01-01T00:00:00.000Z"
  }
}
```

## System Prompts

Each agent has a specialized system prompt that defines:

* **Role**: Agent's expertise and responsibilities
* **Instructions**: Step-by-step process
* **Output Structure**: Required format and sections
* **Constraints**: Rules and limitations

System prompts are defined in `workers/{agent}/src/systemPrompts.ts`.

## Parallel Execution

Some phases support parallel execution:

* **PRD, Data, Logic** - Can execute in parallel (fan-out/fan-in pattern)
* **Design, API, Frontend** - Sequential execution
* **Deployment** - Final phase, sequential

## Related Documentation

* [Supervisor API](/parti-architecture/api/supervisor) - Orchestration API
* [Backend Agents](/parti-architecture/backend/agents) - Implementation details
* [Design Architecture](/parti-architecture/design/architecture) - System architecture