# Daily Brief — Implementation Notes

## Architecture: context-from Chaining

The daily brief uses a **no-agent script → agent curation** pipeline:

```
┌──────────────────────────────┐
│  cron: 0 15 * * *            │
│  script: collector.sh        │  ← no-agent, free public APIs
├──────────────────────────────┤
│  Script stdout → agent       │  ← injected as prompt context
│  context                     │
├──────────────────────────────┤
│  Agent: curates → formats    │  ← lightweight LLM pass only
│  → delivers to Telegram      │
└──────────────────────────────┘
```

## Cost Breakdown

| Stage | Token Cost | Frequency |
|-------|-----------|-----------|
| Script fetch (shell) | $0 | 1x per tick |
| Agent curation | Full model | 1x per tick |
| **Total vs old approach** | **~90% cheaper** | Old: agent had to web search + X search (both failing) |

## Sources (Free, No API Key)

| Source | Endpoint | Reliability |
|--------|----------|-------------|
| Weather | `wttr.in/Placerville,CA` | 99.9% |
| Hacker News | Firebase API (v0) | 99.9% |
| GitHub Trending | `api.github.com/search/repositories` | 99% (unauthed rate limit: 60/hr — fine for daily) |

## Previous State (Before June 20)

The old prompt instructed the agent to use web_search and x_search tools to gather data. Both were failing silently — Firecrawl was unconfigured and xAI credits were exhausted. The brief was returning `[SILENT]` every run (zero useful output for weeks).

## Key Insight

The **script + context_from** pattern from the masterclass turned a dead cron job into a working one in <5 minutes, with zero ongoing API costs. The script does the heavy lifting (API calls, parsing), and the agent only does the lightweight curation pass.