daruma-core

Pure domain layer for Daruma: failure classification, channel health (circuit breaker), and the recovery decision engine. Zero Node runtime dependencies — no node:* imports, no DSH symbols.

Domain

• FailureCode — provider-neutral taxonomy (RATE_LIMIT, SERVER, TIMEOUT, TRANSPORT, EMPTY_RESPONSE, QUOTA, CONTEXT_WINDOW_EXCEEDED, INVALID_CREDENTIAL, UNKNOWN).
• ChannelHealth — circuit-breaker state machine (HEALTHY → COOLDOWN → PROBE → HEALTHY).
• decide() — pure decision engine: same input → same RecoveryPlan (RETRY_NOW / FAILOVER / GIVE_UP).

Ports

Clock, ChannelHealthStore — defined here, implemented by the host adapter (dsh-daruma).

API

import { decide, channelId, modelId } from 'daruma-core'

const plan = decide({
  signal: { code: 'QUOTA', channel: channelId('mt::a'), occurredAtMs: Date.now() },
  healths: new Map(),
  failoverCount: 0,
  config: {
    channels: [
      { id: channelId('mt::a'), provider: 'mt', model: modelId('a') },
      { id: channelId('mt::b'), provider: 'mt', model: modelId('b') },
    ],
    failureBudget: 3,
    cooldownMs: 30_000,
    giveUpBudget: 8,
  },
  nowMs: Date.now(),
})
// plan.verdict.kind === 'FAILOVER'

Development

pnpm --filter daruma-core build
pnpm --filter daruma-core test