Ax Learn

Modes

• batch: offline prompt learning only.
• continuous: offline optimization plus bounded feedback-aware applyUpdate(...).
• playbook: structured context/playbook learning plus applyUpdate(...).

Preferred Construction

import {
  AxLearn,
  ax,
  ai,
  type AxCheckpoint,
  type AxStorage,
  type AxTrace,
} from '@ax-llm/ax';

const storage: AxStorage = {
  save: async (_name, _item) => {
    // persist trace/checkpoint
  },
  load: async (_name, _query) => {
    // return traces/checkpoints
    return [];
  },
};

const teacher = ai({
  name: 'openai',
  apiKey: process.env.OPENAI_APIKEY!,
});

const runtimeAI = ai({
  name: 'openai',
  apiKey: process.env.OPENAI_APIKEY!,
});

const gen = ax(`
  customerQuery:string "User message" ->
  supportReply:string "Agent reply"
`);

const agent = new AxLearn(gen, {
  name: 'support-bot-v1',
  storage,
  teacher,
  runtimeAI,
  mode: 'continuous',
  budget: 12,
  examples: [
    {
      customerQuery: 'Where is my order?',
      supportReply: 'Your order is in transit and should arrive in 2 days.',
    },
    {
      customerQuery: 'I need a refund.',
      supportReply: 'I can help with that. Please share your order number.',
    },
  ],
  generateExamples: false,
});

await agent.ready();

Runtime Pattern

const prediction = await agent.forward(runtimeAI, {
  customerQuery: 'My package is late.',
});

const traces = await agent.getTraces({ limit: 1 });
if (traces[0]) {
  await agent.addFeedback(traces[0].id, {
    score: 0,
    label: 'needs-empathy',
    comment: 'Acknowledge the frustration more directly.',
  });
}

Offline Optimization

const result = await agent.optimize({
  // Optional overrides
  budget: 20,
});

console.log(result.mode);
console.log(result.score);
console.log(result.improvement);
console.log(result.checkpointVersion);

result.improvement is the gain relative to the prior/restored score.

Continuous Update

Use applyUpdate(...) only in continuous or playbook mode.

• In continuous mode, example may be input-only.
• prediction is the observed runtime output being critiqued.
• If example includes expected output fields, that expected-output row stays eligible for scored optimization.
• The observed prediction row is feedback/reflection context, not a scored train/validation row by itself.
• Feedback-bearing scored examples should stay in the training pool when non-feedback rows can fill validation.
• In playbook mode, getInstruction() returns the active composed prompt.

const update = await agent.applyUpdate({
  example: {
    customerQuery: 'My package is late.',
  },
  prediction,
  feedback: {
    score: 0,
    label: 'needs-empathy',
    comment: 'Acknowledge the frustration more directly.',
  },
});

Playbook Mode

• Use mode: 'playbook' when the learned artifact should be structured guidance, not just an instruction tweak.
• Playbook checkpoints restore through ready().
• applyUpdate(...) in playbook mode performs an online structured update.
• getInstruction() should be treated as the active composed runtime prompt, even before optimization if the base prompt lives in the signature description.
• artifact.playbookSummary should match the persisted checkpoint state.artifactSummary.

How Learning Data Is Used

• examples and usable traces become scored optimization rows.
• Feedback stored with addFeedback(...) becomes reflection feedback for later optimization.
• In continuous updates, example + prediction + feedback is used as an observed feedback event.
• Input-only update examples are useful for reflection, but they are not promoted into scored examples unless expected outputs are present.

Important Options

const agent = new AxLearn(gen, {
  name: 'agent-id',
  storage,
  teacher,
  runtimeAI,
  mode: 'batch', // 'batch' | 'continuous' | 'playbook'
  budget: 20,
  metric: async ({ prediction, example }) => {
    return prediction.supportReply === example.supportReply ? 1 : 0;
  },
  criteria: 'accuracy and tone',
  judgeOptions: {},
  examples: [],
  useTraces: true,
  generateExamples: false,
  synthCount: 20,
  validationSplit: 0.2,
  continuousOptions: {
    feedbackWindowSize: 25,
    maxRecentTraces: 100,
    updateBudget: 4,
  },
  playbookOptions: {
    maxEpochs: 2,
  },
  onTrace: (trace) => {
    console.log(trace.id);
  },
  onProgress: (progress) => {
    console.log(progress.round, progress.score);
  },
});

Result Shape

type AxLearnResult = {
  mode: 'batch' | 'continuous' | 'playbook';
  score: number;
  improvement: number;
  checkpointVersion: number;
  stats: {
    trainingExamples: number;
    validationExamples: number;
    feedbackExamples: number;
    durationMs: number;
    mode: 'batch' | 'continuous' | 'playbook';
  };
  state?: {
    mode: 'batch' | 'continuous' | 'playbook';
    instruction?: string;
    baseInstruction?: string;
    score?: number;
    continuous?: {
      feedbackTraceCount?: number;
      lastUpdateAt?: string;
    };
    playbook?: Record<string, unknown>;
    artifactSummary?: Record<string, unknown>;
  };
  artifact?: {
    playbook?: Record<string, unknown>;
    playbookSummary?: {
      feedbackEvents: number;
      historyBatches: number;
      bulletCount: number;
      updatedAt?: string;
    };
    lastUpdateAt?: string;
    feedbackExamples?: number;
  };
};

Storage Notes

• AxStorage.save(name, item) receives either a trace or checkpoint.
• AxStorage.load(name, query) should return arrays of traces or checkpoints.
• Checkpoints may be returned unsorted. AxLearn restores the newest one client-side.

Do This

• Use runtimeAI explicitly.
• Await ready() before relying on restored state.
• Run optimize() off the hot path.
• Use continuous mode when you want bounded feedback-aware updates.
• Use playbook mode when you want persistent structured guidance.
• Pass the real observed model output as prediction in applyUpdate(...).
• Treat getInstruction() in playbook mode as the live composed prompt, not just the raw base instruction.

Avoid This

• Do not assume teacher is the optimized runtime model.
• Do not call applyUpdate() in batch mode.
• Do not claim feedback affects learning unless you are storing it with addFeedback(...) or passing it to applyUpdate(...).
• Do not assume checkpoints load synchronously in the constructor.
• Do not treat prediction as the gold answer in continuous updates.