For people who build with AI coding agents

Your AI wrote it. Can you explain it?

Paste the code your agent wrote, explain it back in your own words, and get a line-by-line map of what you actually understand — before it ships.

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Preview · Token-bucket rate limiter0/4 explained

1import type { Request, Response, NextFunction } from "express";

3interface Bucket {
tokens: number;
lastRefill: number;
6}

8export function createRateLimiter(capacity = 10, refillPerSecond = 1) {
const buckets = new Map<string, Bucket>();

function refill(bucket: Bucket, now: number) {
  const elapsed = (now - bucket.lastRefill) / 1000;
  bucket.tokens = Math.min(capacity, bucket.tokens + elapsed * refillPerSecond);
  bucket.lastRefill = now;
}

return function rateLimit(req: Request, res: Response, next: NextFunction) {
  const key = req.ip ?? "anonymous";
  const now = Date.now();
  let bucket = buckets.get(key);

  if (!bucket) {
    bucket = { tokens: capacity, lastRefill: now };
    buckets.set(key, bucket);
  }

  refill(bucket, now);

  if (bucket.tokens < 1) {
    const retryAfter = Math.ceil((1 - bucket.tokens) / refillPerSecond);
    res.setHeader("Retry-After", String(retryAfter));
    return res.status(429).json({ error: "Too many requests" });
  }

  bucket.tokens -= 1;
  next();
};
38}

0%owned

Bring the code

Paste a function, component or script your agent wrote. TeachBack splits it into the few chunks that carry the real decisions.

Explain it back

One review-style question per chunk. Answer in plain words. The AI grades the understanding, not your vocabulary, and tells you what you missed.

See your Ownership Map

Every line painted owned, shaky or blind spot — plus a prompt that turns your gaps into a lesson from your own coding agent.

The problem

"It works" isn't the same as "I get it."

Agents hand back code that runs but that you couldn't defend in a code review, debug at 2 a.m., or safely change next week. Asking the AI to "explain this" gives you a wall of text you read passively and forget.

The method

Teach-back, from medicine to code.

Nurses confirm a patient understood instructions by asking them to explain it back. Retrieval beats re-reading. TeachBack applies that to AI pair programming — and then flips it: your blind spots become a prompt that has your agent quiz you.

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