---
title: "Signature-Agent header: definition | Agent Ready Crawlers"
description: "Signature-Agent header: The request header in Web Bot Auth that names the URL of the signer's key directory, telling the site where to fetch public keys."
canonical: https://agentreadycrawlers.com/glossary/signature-agent-header
site: "Agent Ready Crawlers"
last_updated: 2026-11-04
section: "Glossary"
---

# Signature-Agent header: definition | Agent Ready Crawlers

> Signature-Agent header: The request header in Web Bot Auth that names the URL of the signer's key directory, telling the site where to fetch public keys.

Source: https://agentreadycrawlers.com/glossary/signature-agent-header
Site: Agent Ready Crawlers
Last reviewed: 2026-11-04

Glossary

# Signature-Agent header

In short

The request header in Web Bot Auth that names the URL of the signer's key directory, telling the site where to fetch public keys. Log it on every request: it is the only field that tells you which key directory to fetch. Example: ChatGPT's Cloud browser sends Signature-Agent: "https://chatgpt.com". Related: Verify Web Bot Auth signatures and ChatGPT agent profile.

## Definition

The request header in Web Bot Auth that names the URL of the signer's key directory, telling the site where to fetch public keys.

## Sourced example

ChatGPT's Cloud browser sends Signature-Agent: "https://chatgpt.com". [Source](https://help.openai.com/en/articles/11845367-chatgpt-agent-allowlisting), read 2026-11-04.

## How it shows up here

Log it on every request: it is the only field that tells you which key directory to fetch.

-   [Verify Web Bot Auth signatures](https://agentreadycrawlers.com/guides/verify-web-bot-auth/)
-   [ChatGPT agent profile](https://agentreadycrawlers.com/crawlers/chatgpt-agent/)

Previous: [Search-index crawler](https://agentreadycrawlers.com/glossary/search-index-crawler/). Next: [Signed agent](https://agentreadycrawlers.com/glossary/signed-agent/). [All 41 terms](https://agentreadycrawlers.com/glossary/).

## Sources

-   [ChatGPT Work's Cloud browser allowlisting](https://help.openai.com/en/articles/11845367-chatgpt-agent-allowlisting) read 2026-11-04

Last reviewed 2026-11-04