Agent Grade / AI bots by site / nasa.gov
Does nasa.gov block ChatGPT?
nasa.gov lets Google and AI search in. ChatGPT search is allowed, and OpenAI's training bot is allowed. From its public robots.txt, checked 23 to 24 October 2026. It ranks #360 on the Tranco list of top sites.
| Bot | What it does | Home page | Deciding rule |
|---|---|---|---|
| Googlebot | Google Search | Allowed | User-agent: * / Allow: / |
| Bingbot | Bing / Copilot | Allowed | User-agent: * / Allow: / |
| OAI-SearchBot | ChatGPT search | Allowed | User-agent: * / Allow: / |
| ChatGPT-User | ChatGPT (user asks) | Allowed | User-agent: * / Allow: / |
| GPTBot | OpenAI training | Allowed | User-agent: * / Allow: / |
| Claude-SearchBot | Claude search | Allowed | User-agent: * / Allow: / |
| Claude-User | Claude (user asks) | Allowed | User-agent: * / Allow: / |
| ClaudeBot | Anthropic training | Allowed | User-agent: * / Allow: / |
| PerplexityBot | Perplexity search | Allowed | User-agent: * / Allow: / |
| Perplexity-User | Perplexity (user asks) | Allowed | User-agent: * / Allow: / |
| Google-Extended | Gemini training | Allowed | User-agent: * / Allow: / |
| Applebot-Extended | Apple AI training | Allowed | User-agent: * / Allow: / |
| CCBot | Common Crawl | Allowed | User-agent: * / Allow: / |
| meta-externalagent | Meta AI | Allowed | User-agent: * / Allow: / |
| Bytespider | ByteDance | Allowed | User-agent: * / Allow: / |
"Blanket rule": nasa.gov never names that bot; a rule for every bot (User-agent: *) applies. llms.txt: No. robots.txt is what a site asks bots to do; some sites also block bots at the network edge.
Questions
Does nasa.gov block ChatGPT search?
No. In its robots.txt as checked 23 to 24 October 2026, nasa.gov lets OAI-SearchBot, the crawler behind ChatGPT search, read its home page.
Does nasa.gov block GPTBot?
No. nasa.gov lets GPTBot, OpenAI's training crawler, read its home page.
Does nasa.gov block Claude?
ClaudeBot (Anthropic training): allowed. Claude-SearchBot (Claude search): allowed. Claude-User (fetches for a person): allowed.
Does nasa.gov have an llms.txt file?
We did not find an llms.txt file on nasa.gov, or its robots.txt did not allow us to fetch it.
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