health_check

Instructions

Implementation Reference

• src/tools/health_check.ts:26-72 (handler)

  The handler function that executes the health check logic. It iterates over requested chains, calls each adapter's searchProducts with a trivial query ('milch'), measures latency, and returns health status, capabilities, and a summary.

  export async function healthCheckHandler(
    registry: AdapterRegistry,
    input: HealthCheckInput,
  ): Promise<{ chains: HealthCheckResult[]; summary: { healthy: number; unhealthy: number; unregistered: number } }> {
    const all: Chain[] = ['migros', 'coop', 'aldi', 'denner', 'lidl'];
    const requested = input.chains ?? all;
    const timeout = input.timeoutMs ?? 5000;
  
    const results = await Promise.all(requested.map(async (chain): Promise<HealthCheckResult> => {
      const adapter = registry.get(chain);
      if (!adapter) return { chain, registered: false, ok: false };
      const start = Date.now();
      try {
        const r = await Promise.race([
          adapter.searchProducts({ query: TRIVIAL_QUERY, limit: 1 }),
          new Promise<never>((_, reject) => setTimeout(() => reject(new Error('timeout')), timeout)),
        ]);
        const latencyMs = Date.now() - start;
        if (r.ok) {
          return {
            chain, registered: true, ok: true, latencyMs,
            capabilities: { ...adapter.capabilities },
          };
        }
        return {
          chain, registered: true, ok: false, latencyMs,
          error: { code: r.error.code, reason: 'reason' in r.error ? r.error.reason : undefined },
          capabilities: { ...adapter.capabilities },
        };
      } catch (e) {
        const msg = e instanceof Error ? e.message : String(e);
        return {
          chain, registered: true, ok: false,
          error: { code: msg === 'timeout' ? 'timeout' : 'unavailable', reason: msg },
          capabilities: { ...adapter.capabilities },
        };
      }
    }));
  
    const summary = {
      healthy: results.filter((r) => r.ok).length,
      unhealthy: results.filter((r) => r.registered && !r.ok).length,
      unregistered: results.filter((r) => !r.registered).length,
    };
  
    return { chains: results, summary };
  }

• src/tools/health_check.ts:5-11 (schema)

  Zod schema defining the input: optional chains array (enum of known chains) and optional timeoutMs (1-30000).

  export const healthCheckSchema = z.object({
    chains: z.array(z.enum(['migros', 'coop', 'aldi', 'denner', 'lidl', 'farmy', 'volgshop', 'ottos']))
      .optional()
      .describe('Chains to probe. Default: all configured.'),
    timeoutMs: z.number().int().positive().max(30000).optional()
      .describe('Per-chain timeout in milliseconds. Default 5000.'),
  }).describe('Probe each registered chain adapter with a trivial query and report which are healthy. Useful for diagnosing why a particular chain is missing from search/plan results.');

• src/tools/health_check.ts:15-22 (helper)

  TypeScript interface for the per-chain health check result, including registration status, ok flag, latency, error info, and capabilities.

  export interface HealthCheckResult {
    chain: Chain;
    registered: boolean;
    ok: boolean;
    latencyMs?: number;
    error?: { code: string; reason?: string };
    capabilities?: Record<string, boolean>;
  }

• src/index.ts:29-29 (registration)

  Import of healthCheckHandler and healthCheckSchema in the main index.ts file where tools are registered.

  import { healthCheckHandler, healthCheckSchema } from './tools/health_check.js';