jackwener/OpenCLI · warning · CommandExecutionError

${label} returned HTTP 429 (rate limited)

Error message

${label} returned HTTP 429 (rate limited)

What it means

CommandExecutionError thrown by dblpFetch when dblp.org responds with HTTP 429 Too Many Requests. dblp rate-limits clients that issue requests too quickly; the library surfaces this explicitly with guidance because 429 is common and recoverable.

Source

Thrown at clis/dblp/utils.js:45

 * Wraps `fetch` with typed errors. We always set a UA per dblp's
 * polite-fetch guidance (https://dblp.org/faq/How+to+use+the+dblp+search+API.html).
 */
async function dblpFetch(url, label, accept) {
    let res;
    try {
        res = await fetch(url, {
            headers: {
                accept,
                'user-agent': 'opencli-dblp/1.0 (+https://github.com/jackwener/opencli)',
            },
        });
    }
    catch (err) {
        throw new CommandExecutionError(`${label} request failed: ${err?.message ?? err}`, 'Check that dblp.org is reachable from this network.');
    }
    if (!res.ok) {
        if (res.status === 429) {
            throw new CommandExecutionError(`${label} returned HTTP 429 (rate limited)`, 'dblp throttles clients that fetch too aggressively. Wait a few seconds and retry, or lower --limit.');
        }
        if (res.status === 404) {
            throw new EmptyResultError(label, 'dblp returned 404 — the requested record may not exist.');
        }
        throw new CommandExecutionError(`${label} returned HTTP ${res.status}`, 'Inspect the response in a browser at the same URL for more context.');
    }
    return res;
}

export async function dblpFetchJson(path, label) {
    const res = await dblpFetch(`${DBLP_ORIGIN}${path}`, label, 'application/json');
    let body;
    try {
        body = await res.json();
    }
    catch (err) {
        throw new CommandExecutionError(`${label} returned malformed JSON: ${err?.message ?? err}`);
    }

View on GitHub (pinned to 49907e53dc)

Solutions

1. Wait a few seconds and retry — 429 is temporary
2. Lower --limit or reduce request frequency; add a sleep between calls
3. Serialize requests instead of running them in parallel
4. Cache results locally to avoid refetching the same records
5. If in CI, add backoff/jitter or route through a less-throttled network

Example fix

// before
for (const name of names) { await run(`dblp author --name ${name}`); }
// Error: dblp author search returned HTTP 429 (rate limited)
// after
for (const name of names) {
  await run(`dblp author --name ${name}`);
  await new Promise(r => setTimeout(r, 2000));
}

// Throttle proactively so 429 never happens.
const limiter = pLimit(1); // serialize dblp calls
const throttled = (fn) => (...a) => limiter(async () => {
  await sleep(1500);
  return fn(...a);
});

async function withBackoff(fn, tries = 4) {
  for (let i = 0; i < tries; i++) {
    try { return await fn(); }
    catch (err) {
      if (/HTTP 429/.test(err.message) && i < tries - 1) {
        await sleep(2 ** i * 1000);
        continue;
      }
      throw err;
    }
  }
}

When it happens

Trigger: Any dblp subcommand executed repeatedly in quick succession — e.g. scripting many `dblp author`/`dblp paper` calls in a tight loop without delay, possibly shared across users behind one IP (CI runners, NAT).

Common situations: Batch scripts iterating over many authors/papers; parallel CI jobs hammering dblp from one IP; shared office/campus IP already throttled; aggressive retry loops.

Understand the failure class

• HTTP status errors: handling 4xx and 5xx responses — how to handle 4xx and 5xx responses properly.

Related errors

• coingecko returned HTTP 429 (rate limited)
• coingecko returned HTTP 429 (rate limited)
• coingecko derivatives returned HTTP 429 (rate limited)
• coingecko returned HTTP 429 (rate limited)
• coingecko returned HTTP 429 (rate limited)

AI-assisted analysis of jackwener/OpenCLI@49907e53dc (2026-08-29). Data as JSON: /api/errors/5e0c90b053559e0e. Report an issue: GitHub.