@pcn-js/core

Core PCN implementation: verification engine, claims manager, and HTML processing.

Claims manager

Central cache and lookup for claims. Register claims by id (e.g. from tool results that include claim_id), then use get/getAll when processing content or with @pcn/ui components.

import { ClaimsManager, createDataPointExtractor } from "@pcn-js/core";

const manager = new ClaimsManager();

// Register one claim
manager.register("claim-1", { value: 42, country: "KEN", date: "2023" });

// Register an extractor for a tool that returns data points
manager.registerExtractor(
  "get_data",
  createDataPointExtractor({
    dataKey: "data",
    claimIdKey: "claim_id",
    valueKey: "OBS_VALUE",
    countryKey: "REF_AREA",
    dateKey: "TIME_PERIOD",
  })
);

// When a tool result arrives
manager.ingest("get_data", toolResult);

manager.get("claim-1");       // Claim | undefined
manager.getAll();             // Record<string, Claim>
manager.has("claim-1");       // boolean
manager.clear();

Optional: set manager.onChange = () => { ... } so UI (e.g. React) can re-render when claims change.

Data point extractor

For tools that return { data: [{ claim_id, value, country?, date?, ... }] }, use createDataPointExtractor so you don’t write custom extractors. See example above.

HTML processing

• extractClaimsFromHtml(html) – returns ClaimTag[] for all <claim> elements.
• processPCNClaims(html, claims) – replaces each <claim> with verified/pending markup (HTML string). Use when you render that HTML (e.g. with dangerouslySetInnerHTML).

For React/streaming UIs, use @pcn/ui and the ClaimMark component instead of injecting HTML.

Exports

• Types: Claim, Policy, ClaimTag, ClaimEntry, ToolResultExtractor, DataPointExtractorOptions
• ClaimsManager, createDataPointExtractor
• compareByPolicy, withMark, pcnPolicy, processPCN, extractClaimsFromHtml, processPCNClaims
• escapeAttr, toTitleAttr