Header Modification
FastGateway can add, overwrite, or strip HTTP headers on both requests and responses. You configure this in the route builder, with no YAML to write.
Where to configure
In the route builder, open the Traffic tab and expand the Header Modifiers section. It has two groups:
- Request Headers change headers before the request is forwarded to the backend.
- Response Headers change headers on the response sent back to the client.
Click Add in either group to create a row. Each row has three parts:
- An operation: Set, Add, or Remove.
- The header name (for example
X-Custom-Header). - The header value (hidden for Remove, since the header is just dropped).
Add as many rows as you need, then save the route.
Operations
| Operation | Description |
|---|---|
| Set | Sets the header value, overwriting any existing value |
| Add | Adds the header value, appending to any existing values |
| Remove | Removes the header completely |
Common Use Cases
- Add tracing headers (X-Request-ID, X-Trace-ID)
- Remove sensitive headers (Server, X-Powered-By)
- Set security headers (X-Frame-Options, X-Content-Type-Options)
- Add authentication context headers
After saving, the change goes through the approval workflow and is then deployed.
The REST API equivalent is documented in the API Reference.