Bolt-Agent
Bolt-Agent is an AI coding tool operated by Stackblitz. Developers use it to write, debug, or understand code, and it visits the web to fetch documentation, package metadata, code samples, or related references.
Visits are user-initiated. A developer types a question or pastes a URL and Bolt-Agent retrieves it on their behalf. You will not see scheduled crawling, just bursts that follow user activity.
Allowing this agent makes your developer documentation available to a much larger audience than just the people who land on your site directly. Your docs end up inside the IDE.
See Bolt-Agent on your own site
Match the User-Agent header on incoming requests against the pattern below.
regex
For higher confidence, also verify the source IP against the operator's published ranges. UA strings can be spoofed; IP ownership is harder to fake.
Renders JavaScript
Sometimes
IP verification
User-Agent only
Crawl frequency
Burst, user-driven
Honors robots.txt
Yes
Honors Crawl-delay
Varies
Stackblitz runs 2 bots in total. Each one is a separate user-agent so you can allow or block them independently.
AI Coding Tool
1- Bolt-AgentYou are here
Agentic Browser
1Should I let Bolt-Agent through?
In most cases, yes. Lets your developer documentation reach a much larger audience inside the IDE. If volume gets noisy, rate-limit it before you block it outright.
Does blocking Bolt-Agent affect my Google rankings?
No. Bolt-Agent fetches a page only when a user is actively asking Stackblitz a question. It has nothing to do with how Google or Bing rank you. The cost of blocking is that Stackblitz can't quote your content in its answer.
How do I confirm a request is really from Bolt-Agent?
Look at the User-Agent header in your access logs and match it against the strings listed above. Worth knowing that the User-Agent is easy to fake, so this check tells you "the traffic claims to be Bolt-Agent", not "the traffic is genuinely Bolt-Agent". If you need stronger guarantees, look for a reverse-DNS check or wait for Stackblitz to publish IP ranges.
Does a Bolt-Agent visit count as a real user visit?
Sort of. There is a human asking Stackblitz a question on the other end, but they never load your page in their own browser. They see whatever Stackblitz quotes back, usually a snippet plus a citation link. Count it as upstream attention rather than as a session.
How is Bolt-Agent different from Stackblitz's other bots?
Stackblitz splits work across multiple user-agents so site owners can decide on each one independently. Training crawlers, live-fetch agents, search indexers, and agentic browsers each get their own name. Worth scanning the rest of the Stackblitz family above to see which ones actually matter for your site.
What's the cleanest way to control Bolt-Agent?
Two layers. Robots.txt for the polite crawlers that read it, and rules at your CDN or edge for the ones that don't. Rankly's Agent Experience handles both from a single config, so you can allow, block, rate-limit, or serve a stripped-down version per bot. Agent Analytics handles the observation half so you know which bots are actually worth a rule.