intermediatetypescript

Context Window Checkpoint

Persist agent state at a natural pause point so a future invocation can resume without replaying the full history.

Code

import { createCheckpoint, loadCheckpoint } from '@dcyfr/ai';

// --- At pause point ---
const checkpoint = createCheckpoint({
  goal: 'Refactor auth module',
  completedSteps: [
    'Read src/auth/jwt.ts — found missing expiry validation',
    'Updated jwt.ts with validateExpiry() call',
  ],
  openQuestions: [
    'Does refreshToken flow also bypass expiry check?',
  ],
  keyFacts: {
    affectedFiles: ['src/auth/jwt.ts', 'src/auth/refresh.ts'],
    breakingChange: false,
  },
});

await checkpoint.save('auth-refactor-session-1');

// --- On next invocation ---
const state = await loadCheckpoint('auth-refactor-session-1');
console.log('Resuming:', state.goal);
console.log('Open questions:', state.openQuestions);

How it works

Checkpoints are the antidote to context degradation in long-running tasks. Rather than keeping 50k tokens of history, save a structured state object at natural pause points. The next invocation loads the checkpoint and resumes from a clean, high-signal context.

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