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WebRun runs AI agents inside real browsers on behalf of users. So that site operators, CDNs, and bot-management providers such as Cloudflare can recognize this traffic - and tell it apart from spoofed or malicious automation - WebRun publishes a stable, verifiable bot identity. This page is the canonical, public reference for that identity. It documents the User-Agent, the cryptographic and network-level ways to verify a request genuinely originates from WebRun, and the behavior operators can expect. It also serves as the public documentation required by Cloudflare’s Verified Bots program.
Verifying identity matters. A malicious client can copy WebRun’s User-Agent string, but it cannot forge a valid message signature or originate from WebRun’s published egress IPs. Always verify before allow-listing.

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User-Agent

WebRun’s automated traffic identifies itself with the WebRunAgent product token in the User-Agent header:
The token meets Cloudflare’s Verified Bots policy requirements for a User-Agent: it is longer than five characters, contains no special characters, and is unique to WebRun.
The underlying browser can still present a standard Chrome User-Agent for individual page rendering (see What User-Agent does WebRun use?). The WebRunAgent token and the verification methods below are how WebRun’s traffic is identified and authenticated at the network layer - they do not depend on the browser’s rendering User-Agent, so match on the signature or egress IP when you need a spoof-proof signal.

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Verifying WebRun traffic

Use either method below to confirm a request is genuinely from WebRun. Message signatures are preferred - they verify each request independently and are Cloudflare’s recommended method - with IP-range and reverse-DNS validation available as a fallback for operators who filter by network.

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HTTP Message Signatures (Web Bot Auth)

WebRun signs its requests using HTTP Message Signatures, the mechanism behind Cloudflare’s Web Bot Auth. Each request carries Signature and Signature-Input headers signed with a key published in WebRun’s public key directory:
To verify:
1

Fetch the key directory

Retrieve the JSON Web Key Set from https://webrun.ai/.well-known/http-message-signatures-directory. Cache it and refresh periodically; keys rotate.
2

Match the keyid

Read the keyid from the request’s Signature-Input header and select the matching public key from the directory.
3

Verify the signature

Verify the Signature header over the covered components per RFC 9421. A valid signature proves the request came from WebRun and was not tampered with in transit.
Cloudflare customers do not need to implement this manually. Once WebRun is approved in the Verified Bots directory, signed WebRun requests are matched automatically and exposed through the cf.bot_management.verified_bot field.

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IP ranges and reverse DNS

WebRun’s identifiable agent traffic originates from a stable, published set of egress IP ranges. The authoritative, machine-readable list is served at:
Always fetch the live list - do not hardcode individual addresses. Ranges change as capacity scales, and the JSON endpoint is the single source of truth. Requests routed through WebRun-managed or custom proxies intentionally exit from proxy IPs and will not appear in this list.
Each egress IP is also validated with forward-confirmed reverse DNS. To verify an IP without the range list:
1

Reverse lookup

Run a reverse DNS (PTR) lookup on the source IP. WebRun addresses resolve to a hostname under bot.webrun.ai, for example edge-203-0-113-7.bot.webrun.ai.
2

Forward-confirm

Run a forward DNS (A/AAAA) lookup on that hostname and confirm it resolves back to the original source IP. This forward-confirmation step is what makes the check spoof-resistant - never trust the PTR record alone.

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Expected behavior

WebRun operates as a transparent, well-behaved agent. Operators can expect the following from WebRunAgent traffic:
  • User-initiated, not mass crawling. Traffic is generated by explicit user automation tasks running in isolated browser sessions, not by autonomous, large-scale site indexing.
  • No automated CAPTCHA solving or bot-defense evasion. When a CAPTCHA or challenge is encountered, the session pauses for human takeover - WebRun does not attempt to defeat it programmatically (see handling CAPTCHAs).
  • Respects rate-limiting signals. WebRun honors 429 Too Many Requests responses and the Retry-After header, and backs off accordingly.
  • Honors robots.txt. WebRun observes robots.txt directives that target the WebRunAgent token (see Controlling WebRun).
  • Isolated, ephemeral sessions. Each session is a clean browser instance with no shared cookies, cache, or state, destroyed on termination.
  • Encrypted transport. All WebRun traffic uses HTTPS/TLS.

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Cloudflare Verified Bots

WebRun participates in Cloudflare’s Verified Bots program so that Cloudflare-protected sites can distinguish legitimate WebRun traffic from spoofed automation and apply their own allow, challenge, or rate-limit policies to it. If you run a Cloudflare-protected site, you can identify verified WebRun requests using the cf.bot_management.verified_bot field in a WAF custom rule, and allow-list them following Cloudflare’s guide for allowing verified bots. For the WebRun team, the Verified Bots application is submitted from the Cloudflare dashboard under Manage Account → Configurations → Bot Submission Form, using this page as the required public documentation, the WebRunAgent User-Agent, and the message-signature key directory above.

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Controlling WebRun traffic

Site operators can allow, throttle, or disallow WebRun using standard mechanisms.

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robots.txt

Target the WebRunAgent token directly:

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Firewall / WAF rules

Match on the verified-bot signal or the WebRunAgent User-Agent to allow, rate-limit, or block WebRun at the edge. Prefer matching the verified-bot field or a validated signature over the raw User-Agent string, since the User-Agent alone can be spoofed.
Blocking WebRun blocks the automation your own users have asked WebRun to run on your site. If WebRun traffic is causing load problems, consider rate-limiting or contacting us before an outright block.

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Reporting abuse

If you believe WebRun traffic is misbehaving on your site, email abuse@webrun.ai with the affected domain, timestamps (with timezone), and a sample of request logs (source IP and User-Agent). Verified reports are investigated promptly. For general questions, contact support@webrun.ai.

Proxies

Route sessions through proxy IPs instead of WebRun’s egress ranges

Sessions

How WebRun’s isolated browser sessions work

Automation Policies

Runtime rules that constrain agent behavior

FAQs

Technical details, including the browser User-Agent