Header Relay

About

Header Relay helps developers verify browser-based HTTP request behavior when an API or web app depends on custom headers, gateway headers, session tokens, trace IDs, or environment-specific request metadata.

Create a profile, choose target origins, configure fixed request headers, and list response headers to capture. When a matching response includes a configured captured header, Header Relay stores that value locally and uses Chrome declarativeNetRequest session rules to attach it to later matching requests.

Main features:

- Origin-scoped header relay for local, staging, internal, and test environments.
- Fixed request headers for values that should always be attached.
- Captured response headers for values such as session tokens, trace IDs, or gateway headers.
- Excluded path prefixes for assets or endpoints that should not receive relay-managed headers.
- URL Probe to check whether a URL is matched, excluded, and which headers would be attached.
- Popup status view for active headers, captured values, session state, and DNR rule count.
- Local audit logs with automatic retention and query-string removal.

Privacy and security:

- Header Relay does not send captured headers, profile settings, audit logs, or browsing data to external servers.
- Captured values are stored locally in the browser extension storage area.
- Audit logs store only origin and pathname, not query strings or fragments.
- The broad host permission is constrained by your enabled profile's Target Origins and Excluded Paths.

This extension is intended for developers and QA workflows. Do not use it to store production credentials unless that is acceptable for your local browser profile.