# linkedin-trends-store

Persistent **trend store** — the foundation layer of the research engine
(retning §5). A topic-tagged, provenance-bearing inventory of trend signals
captured over time, so the engine accumulates **history** instead of starting
amnesiac each session.

Twin of [`scripts/specifics-bank`](../specifics-bank): same deterministic
store / dedup / query discipline, different dedupe key — a trend is identified by
its **normalized title+URL**, not by free-text content.

## Generic by architecture

Nothing niche-specific lives here. A `TrendRecord` carries free-form `topics`
tags and a free-form `source` string; *which* topics matter and *which* sources
to poll are decided upstream (config/profile + the capture agent), never
hard-coded in this module. The same store serves any niche.

## Data location

The store lives under the per-user data dir (M0 data-path convention), so trend
history survives plugin upgrades/reinstalls:

```
${LINKEDIN_STUDIO_DATA:-$HOME/.claude/linkedin-studio}/trends/trends.json
```

`LINKEDIN_STUDIO_DATA` overrides the root. No path is hard-coded in prose.

## Record shape (minimal generic core)

```ts
interface TrendRecord {
  id: string;          // sha256(normalized title+url).slice(0,12) — also the dedupe key
  title: string;       // headline, verbatim
  url: string;         // source URL, verbatim
  source: string;      // "tavily" | "websearch" | "manual" | <mcp-name>
  capturedAt: string;  // ISO-8601 date
  topics: string[];    // query tags; unioned across re-captures
  summary?: string;    // optional, verbatim
}
```

Fields (relevance score, first-mover timing, status) can be added in a later
slice without breaking the shape.

## CLI

```bash
# Capture a freshly-polled trend (dedupes on title+url; unions topics on re-capture)
node --import tsx src/cli.ts add \
  --title "Agentic workflows hit production" \
  --url "https://example.com/agentic" \
  --topics "agents,engineering" --source tavily \
  --summary "Teams ship multi-step agents past the demo stage."

# Topic-scoped history — trends matching these topics, ranked by overlap then recency
node --import tsx src/cli.ts query --topics "agents,engineering" [--json]

# Time-scoped history — newest first, optionally windowed/capped
node --import tsx src/cli.ts list [--since 2026-06-01] [--limit 10] [--json]
```

Re-running `add` with the same title+url never appends a duplicate.

## Tests

```bash
cd scripts/trends
npm install
npm test     # deterministic store: normalize/id, load/save, dedup+union, query, history
npm run build
```