fix(invariants): enforce runtime relationships

packages/llm/llm-retry/README.md

@@ -6,6 +6,8 @@ The default policy permits two retries for `RATE_LIMIT`, `SERVER`, `TIMEOUT`, an
 
 Before waiting, the plugin appends a non-surface `llm/retry` event with the failure and scheduled delay. Cancellation and plugin disposal abort the wait; disposal drains the plugin's active backoffs, and a callback captured before disposal fails closed if invoked afterward.
 
+The separately published `./invariant` companion checks that every retry record names the current open turn and its latest closed step, has a unique step record and increasing retry number, and carries a positive bounded retry budget and timer delay.
+
 ```yaml
 - name: '@deepseek-ai/dsh-llm-retry'
   config:

packages/llm/llm-retry/package.json

@@ -11,10 +11,15 @@
       "types": "./lib/types/index.d.ts",
       "default": "./lib/index.js"
     },
+    "./invariant": {
+      "types": "./lib/types/invariant.d.ts",
+      "default": "./lib/invariant.js"
+    },
     "./package.json": "./package.json"
   },
   "files": [
     "lib/index.js",
+    "lib/invariant.js",
     "lib/types/**/*.d.ts",
     "lib/types/**/*.d.ts.map",
     "src"
@@ -22,6 +27,7 @@
   "license": "BSD-3-Clause",
   "peerDependencies": {
     "@deepseek-ai/dsh-agent": "^0.0.1",
+    "@deepseek-ai/dsh-invariants": "^0.0.1",
     "@deepseek-ai/dsh-llm": "^0.0.1",
     "@deepseek-ai/dsh-session": "^0.0.1",
     "@deepseek-ai/dsh-timeout": "^0.0.1",
@@ -35,6 +41,7 @@
     "@cordisjs/plugin-loader": "workspace:^",
     "@deepseek-ai/dsh-agent": "workspace:^",
     "@deepseek-ai/dsh-agent-loop": "workspace:^",
+    "@deepseek-ai/dsh-invariants": "workspace:^",
     "@deepseek-ai/dsh-llm": "workspace:^",
     "@deepseek-ai/dsh-session": "workspace:^",
     "@deepseek-ai/dsh-session-persistence-jsonl": "workspace:^",

packages/llm/llm-retry/src/invariant.ts

@@ -0,0 +1,97 @@
+/** Package-owned durable retry-event invariants. @module @deepseek-ai/dsh-llm-retry/invariant */
+
+import type { Context } from 'cordis'
+import type { Session, SessionEvent } from '@deepseek-ai/dsh-session'
+import { MAX_TIMER_DELAY_MS } from '@deepseek-ai/dsh-timeout'
+import type { InvariantFailure, InvariantInstaller } from '@deepseek-ai/dsh-invariants'
+import type {} from './index.ts'
+
+const PACKAGE_NAME = '@deepseek-ai/dsh-llm-retry'
+
+/** Cordis companion plugin name. */
+export const name = 'llm-retry-invariant'
+/** Service required before the companion can reserve package ownership. */
+export const inject = ['invariants']
+
+/** Validate one retry record against the open turn and most recently closed step. */
+function validateRetry(
+  history: readonly SessionEvent[],
+  event: SessionEvent<'llm/retry'>,
+  fail: InvariantFailure,
+): void {
+  const { turn, step, retry, maxRetries, delayMs } = event.data
+  if (!Number.isSafeInteger(retry) || retry < 1) {
+    fail('llm/retry retry must be a positive safe integer')
+  }
+  if (!Number.isSafeInteger(maxRetries) || maxRetries < 1 || retry > maxRetries) {
+    fail(`llm/retry retry ${retry} must not exceed a positive safe maxRetries ${maxRetries}`)
+  }
+  if (!(delayMs > 0 && delayMs <= MAX_TIMER_DELAY_MS)) {
+    fail(`llm/retry delayMs must be within 1..${MAX_TIMER_DELAY_MS}`)
+  }
+
+  const currentTurnEvents: SessionEvent[] = []
+  let openTurn: number | undefined
+  for (const prior of history.slice().reverse()) {
+    if (prior.type === 'turn/end') fail('llm/retry must be appended inside an open turn')
+    if (prior.type === 'turn/start') {
+      openTurn = prior.data.turn
+      break
+    }
+    currentTurnEvents.push(prior)
+  }
+  if (openTurn === undefined) fail('llm/retry must be appended inside an open turn')
+  if (turn !== openTurn) {
+    fail(`llm/retry names turn ${turn}, but the open turn is ${openTurn}`)
+  }
+
+  let closedStep: number | undefined
+  for (const prior of currentTurnEvents) {
+    if (prior.type === 'step/start') {
+      fail(`llm/retry must follow step/end, but step ${prior.data.step} is still open`)
+    }
+    if (prior.type === 'step/end') {
+      closedStep = prior.data.step
+      break
+    }
+  }
+  if (closedStep === undefined || step !== closedStep) {
+    fail(`llm/retry names step ${step}, but the latest closed step is ${String(closedStep)}`)
+  }
+
+  const priorRetries = currentTurnEvents
+    .filter((prior): prior is SessionEvent<'llm/retry'> => prior.type === 'llm/retry')
+  if (priorRetries.some(prior => prior.data.step === step)) {
+    fail(`llm/retry duplicates the retry record for turn ${turn}/step ${step}`)
+  }
+  const priorRetry = priorRetries[0]
+  if (priorRetry !== undefined && retry <= priorRetry.data.retry) {
+    fail(`llm/retry retry ${retry} must increase after retry ${priorRetry.data.retry}`)
+  }
+}
+
+/** Validate every retry record already present in one loaded session. */
+function validateSession(session: Session, fail: InvariantFailure): void {
+  for (const [index, event] of session.events.entries()) {
+    if (event.type === 'llm/retry') validateRetry(session.events.slice(0, index), event, fail)
+  }
+}
+
+/** Install validation for loaded and newly appended retry records. */
+const install: InvariantInstaller = Object.assign((ctx: Context, fail: InvariantFailure) => {
+  for (const session of ctx.sessions.list()) validateSession(session, fail)
+  ctx.on('session/created', (session) => { validateSession(session, fail) }, { global: true })
+  ctx.on('internal/dispatch', (_mode, eventName, args) => {
+    if (eventName !== 'session/event') return
+    const [session, event] = args as [Session, SessionEvent]
+    if (event.type === 'llm/retry') validateRetry(session.events, event, fail)
+  }, { global: true })
+}, { inject: ['sessions'] })
+
+/**
+ * Register the LLM retry invariant companion.
+ * @param ctx - Cordis context carrying the invariant service.
+ * @returns the installed registration's disposer after setup succeeds.
+ */
+export const apply = (ctx: Context): Promise<() => void> =>
+  Promise.resolve(ctx.invariants.register(PACKAGE_NAME, install))

packages/llm/llm-retry/tests/invariant.spec.ts

@@ -0,0 +1,144 @@
+import { describe, expect, it } from 'vitest'
+import { Context } from 'cordis'
+import SessionStore, { SessionId } from '@deepseek-ai/dsh-session'
+import { MAX_TIMER_DELAY_MS } from '@deepseek-ai/dsh-timeout'
+import InvariantService from '@deepseek-ai/dsh-invariants'
+import * as RetryInvariant from '@deepseek-ai/dsh-llm-retry/invariant'
+
+async function setup(): Promise<Context> {
+  const ctx = new Context()
+  await ctx.plugin(SessionStore)
+  await ctx.plugin(InvariantService)
+  await ctx.plugin(RetryInvariant)
+  return ctx
+}
+
+function closeStep(ctx: Context, id: string, turn = 1, step = 1) {
+  const session = ctx.sessions.create(SessionId(id))
+  session.append('turn/start', { turn, trigger: { kind: 'message', source: { kind: 'user' } } })
+  session.append('step/start', { turn, step })
+  session.append('step/end', { turn, step })
+  return session
+}
+
+const failure = { message: 'provider busy', code: 'RATE_LIMIT', status: 429 }
+
+describe('llm-retry invariants', () => {
+  it('accepts increasing retry records for successive closed steps and ignores unrelated events', async () => {
+    const ctx = await setup()
+    const session = closeStep(ctx, 'retry-invariant-valid')
+    expect(() => {
+      session.append('llm/retry', {
+        turn: 1, step: 1, retry: 1, maxRetries: 2, delayMs: 500, failure,
+      })
+      session.append('step/start', { turn: 1, step: 2 })
+      session.append('step/end', { turn: 1, step: 2 })
+      session.append('llm/retry', {
+        turn: 1, step: 2, retry: 2, maxRetries: 2, delayMs: 1_000, failure,
+      })
+    }).not.toThrow()
+    expect(() => { ctx.emit('tools/change') }).not.toThrow()
+  })
+
+  it.each([
+    [{ retry: 0, maxRetries: 2, delayMs: 1 }, /positive safe integer/],
+    [{ retry: 1.5, maxRetries: 2, delayMs: 1 }, /positive safe integer/],
+    [{ retry: 1, maxRetries: 0, delayMs: 1 }, /positive safe maxRetries/],
+    [{ retry: 1, maxRetries: 1.5, delayMs: 1 }, /positive safe maxRetries/],
+    [{ retry: 3, maxRetries: 2, delayMs: 1 }, /must not exceed/],
+    [{ retry: 1, maxRetries: 2, delayMs: 0 }, /delayMs/],
+    [{ retry: 1, maxRetries: 2, delayMs: MAX_TIMER_DELAY_MS + 1 }, /delayMs/],
+  ])('rejects invalid retry bounds %#', async (data, message) => {
+    const ctx = await setup()
+    const session = closeStep(ctx, `retry-invariant-bounds-${data.retry}-${data.maxRetries}-${data.delayMs}`)
+    expect(() => {
+      session.append('llm/retry', { turn: 1, step: 1, ...data, failure })
+    }).toThrow(message)
+  })
+
+  it('rejects retry records outside the matching closed-step boundary', async () => {
+    const ctx = await setup()
+    const absent = ctx.sessions.create(SessionId('retry-invariant-no-turn'))
+    expect(() => {
+      absent.append('llm/retry', {
+        turn: 1, step: 1, retry: 1, maxRetries: 2, delayMs: 1, failure,
+      })
+    }).toThrow(/inside an open turn/)
+
+    const wrongTurn = closeStep(ctx, 'retry-invariant-wrong-turn')
+    expect(() => {
+      wrongTurn.append('llm/retry', {
+        turn: 2, step: 1, retry: 1, maxRetries: 2, delayMs: 1, failure,
+      })
+    }).toThrow(/open turn is 1/)
+
+    const openStep = ctx.sessions.create(SessionId('retry-invariant-open-step'))
+    openStep.append('turn/start', { turn: 1, trigger: { kind: 'message', source: { kind: 'user' } } })
+    openStep.append('step/start', { turn: 1, step: 1 })
+    expect(() => {
+      openStep.append('llm/retry', {
+        turn: 1, step: 1, retry: 1, maxRetries: 2, delayMs: 1, failure,
+      })
+    }).toThrow(/step 1 is still open/)
+
+    const noStep = ctx.sessions.create(SessionId('retry-invariant-no-step'))
+    noStep.append('turn/start', { turn: 1, trigger: { kind: 'message', source: { kind: 'user' } } })
+    expect(() => {
+      noStep.append('llm/retry', {
+        turn: 1, step: 1, retry: 1, maxRetries: 2, delayMs: 1, failure,
+      })
+    }).toThrow(/latest closed step is undefined/)
+
+    const wrongStep = closeStep(ctx, 'retry-invariant-wrong-step')
+    expect(() => {
+      wrongStep.append('llm/retry', {
+        turn: 1, step: 2, retry: 1, maxRetries: 2, delayMs: 1, failure,
+      })
+    }).toThrow(/latest closed step is 1/)
+
+    const closedTurn = closeStep(ctx, 'retry-invariant-closed-turn')
+    closedTurn.append('turn/end', { turn: 1, reason: { kind: 'aborted', reason: 'cancelled' } })
+    expect(() => {
+      closedTurn.append('llm/retry', {
+        turn: 1, step: 1, retry: 1, maxRetries: 2, delayMs: 1, failure,
+      })
+    }).toThrow(/inside an open turn/)
+  })
+
+  it('rejects duplicate and non-increasing retry records', async () => {
+    const ctx = await setup()
+    const duplicate = closeStep(ctx, 'retry-invariant-duplicate')
+    duplicate.append('llm/retry', {
+      turn: 1, step: 1, retry: 1, maxRetries: 3, delayMs: 1, failure,
+    })
+    expect(() => {
+      duplicate.append('llm/retry', {
+        turn: 1, step: 1, retry: 2, maxRetries: 3, delayMs: 1, failure,
+      })
+    }).toThrow(/duplicates the retry record/)
+
+    const nonIncreasing = closeStep(ctx, 'retry-invariant-non-increasing')
+    nonIncreasing.append('llm/retry', {
+      turn: 1, step: 1, retry: 1, maxRetries: 3, delayMs: 1, failure,
+    })
+    nonIncreasing.append('step/start', { turn: 1, step: 2 })
+    nonIncreasing.append('step/end', { turn: 1, step: 2 })
+    expect(() => {
+      nonIncreasing.append('llm/retry', {
+        turn: 1, step: 2, retry: 1, maxRetries: 3, delayMs: 1, failure,
+      })
+    }).toThrow(/must increase/)
+  })
+
+  it('validates existing histories on late registration', async () => {
+    const ctx = new Context()
+    await ctx.plugin(SessionStore)
+    const session = ctx.sessions.create(SessionId('retry-invariant-late'))
+    session.append('step/end', { turn: 1, step: 1 })
+    session.append('llm/retry', {
+      turn: 1, step: 1, retry: 1, maxRetries: 2, delayMs: 1, failure,
+    })
+    await ctx.plugin(InvariantService)
+    await expect(ctx.plugin(RetryInvariant)).rejects.toThrow(/inside an open turn/)
+  })
+})

packages/llm/llm-retry/tsconfig.json

@@ -26,6 +26,9 @@
     {
       "path": "../../core/agent"
     },
+    {
+      "path": "../../support/invariants"
+    },
     {
       "path": "../../util/timeout"
     }