# Pulse — Agent Guide

RSS feed aggregator hosted at pulse.eazz.io.
Built with a strict module-per-agent architecture. Each agent owns one module and communicates with others only through documented interfaces.

---

## Golden Rules

1. **Ask before you build.** If anything is unclear, ask. Do not assume. Do not start coding until you fully understand the task.
2. **Plan before you execute.** Always produce a written plan first. Wait for approval before writing any code.
3. **Stay in your module.** Do not read or write files outside your module folder unless you are the Orchestrator.
4. **Respect the interfaces.** Never call internal functions of another module. Only use what is exported in `interfaces/`.
5. **Small commits, clear messages.** One logical change per commit.
6. **No silent assumptions.** If a requirement is ambiguous, surface it explicitly before proceeding.

---

## Project Structure

```
pulse/
├── AGENTS.md                  # This file
├── interfaces/                # Shared contracts — source of truth for all modules
│   ├── feed.types.ts          # Core data types
│   ├── fetcher.interface.ts   # Fetcher module contract
│   ├── parser.interface.ts    # Parser module contract
│   ├── storage.interface.ts   # Storage module contract
│   ├── dedup.interface.ts     # Deduplication module contract
│   └── formatter.interface.ts # Formatter module contract
├── modules/
│   ├── fetcher/               # HTTP fetching of RSS/Atom feeds
│   ├── parser/                # XML parsing into FeedItem structs
│   ├── dedup/                 # Deduplication of feed items
│   ├── storage/               # Persistence (SQLite)
│   └── formatter/             # Output rendering (terminal / HTML)
├── orchestrator/              # Coordinates modules, owns no business logic
└── opencode.json              # OpenCode agent config
```

---

## Core Data Types

These are defined in `interfaces/feed.types.ts` and are the lingua franca between all modules.

```typescript
export interface FeedItem {
  id: string           // Deterministic hash of url + publishedAt
  source: string       // Feed origin URL
  title: string
  url: string
  publishedAt: Date
  content?: string     // Optional full content
  summary?: string     // Optional short summary
}

export interface FetchError {
  source: string
  reason: string
  code: "NETWORK" | "TIMEOUT" | "PARSE" | "UNKNOWN"
}

export interface FetchResult {
  items: FeedItem[]
  errors: FetchError[]
  fetchedAt: Date
}
```

---

## Module Interfaces

### Fetcher
```typescript
// interfaces/fetcher.interface.ts
export interface IFetcher {
  fetch(feedUrl: string): Promise<FetchResult>
  fetchMany(feedUrls: string[]): Promise<FetchResult>
}
```

### Parser
```typescript
// interfaces/parser.interface.ts
export interface IParser {
  parse(rawXml: string, source: string): Promise<FeedItem[]>
  supports(contentType: string): boolean  // rss, atom, json feed
}
```

### Deduplication
```typescript
// interfaces/dedup.interface.ts
export interface IDedup {
  filter(items: FeedItem[]): Promise<FeedItem[]>  // returns only unseen items
  markSeen(items: FeedItem[]): Promise<void>
}
```

### Storage
```typescript
// interfaces/storage.interface.ts
export interface IStorage {
  save(items: FeedItem[]): Promise<void>
  getRecent(limit: number): Promise<FeedItem[]>
  getBySource(source: string, limit: number): Promise<FeedItem[]>
  search(query: string): Promise<FeedItem[]>
}
```

### Formatter
```typescript
// interfaces/formatter.interface.ts
export type OutputFormat = "terminal" | "html" | "json"

export interface IFormatter {
  format(items: FeedItem[], format: OutputFormat): Promise<string>
}
```

---

## Agent Responsibilities

| Agent | Owns | Can read interfaces | Cannot touch |
|---|---|---|---|
| `orchestrator` | `orchestrator/` | All | `modules/` internals |
| `fetcher-agent` | `modules/fetcher/` | `feed.types`, `fetcher.interface` | All other modules |
| `parser-agent` | `modules/parser/` | `feed.types`, `parser.interface` | All other modules |
| `dedup-agent` | `modules/dedup/` | `feed.types`, `dedup.interface` | All other modules |
| `storage-agent` | `modules/storage/` | `feed.types`, `storage.interface` | All other modules |
| `formatter-agent` | `modules/formatter/` | `feed.types`, `formatter.interface` | All other modules |

---

## Workflow Every Agent Must Follow

### Step 1 — Clarify
Before doing anything, re-read your task. If any of these are unclear, **ask**:
- What exact input will I receive?
- What exact output is expected?
- Are there edge cases not mentioned?
- Does this touch an interface that other modules depend on?

Do not proceed until you have answers.

### Step 2 — Plan
Write a short implementation plan in plain text:
- What files will you create or modify?
- What are the key decisions and why?
- What could go wrong?

Post the plan and **wait for approval** before writing any code.

### Step 3 — Implement
Only after plan approval:
- Stay inside your module folder
- Implement against the interface, not against other module internals
- Write tests alongside the code

### Step 4 — Verify
- Run tests for your module only
- Confirm the exported interface still matches `interfaces/`
- Do not break existing interface contracts without flagging it first

---

## Interface Change Protocol

Interfaces in `interfaces/` are shared contracts. Changing them affects all modules.

If you need to change an interface:
1. Stop. Do not change it unilaterally.
2. Post a proposed change with reasoning to the orchestrator.
3. Wait for explicit approval.
4. Only then update the interface file AND all affected modules in the same commit.

---

## Tech Stack

- Runtime: Node.js (TypeScript)
- Storage: SQLite via `better-sqlite3`
- HTTP: `undici`
- XML parsing: `fast-xml-parser`
- Testing: `vitest`
- Linting: `eslint` + `prettier`
- Web: React + Tailwindcss + shadcn/ui
- Server: Koa


---

## Questions Agents Should Ask Themselves

Before starting any task:
- [ ] Do I fully understand what "done" looks like?
- [ ] Have I read the relevant interface file?
- [ ] Is my plan written and approved?
- [ ] Am I staying inside my module?
- [ ] Will my changes break any existing interface contract?

If any answer is "no" or "unsure" — ask before proceeding.