Rewrites

Rewrites let you modify requests and responses as they pass through the proxy — without pausing traffic. Unlike breakpoints (which pause for manual intervention), rewrites apply automatically and instantly. Use them to redirect traffic, inject headers, replace response bodies, or fix URLs on the fly.

How Rewrites Work

Rewrites are evaluated first in the interception pipeline, before mocks and breakpoints. When a request matches a rewrite rule:

1. The rewrite modifies the request (or response) according to your rules
2. The modified traffic continues through the pipeline normally
3. The original and modified versions are both visible in the traffic detail

Quick Templates

For common scenarios, you don't have to configure rewrites by hand. Madhyamas ships rewrite templates — pre-built rules you can apply with a single click, including No Caching (disable all caching), Block Cookies (strip cookies both ways), Add CORS, HTTP to HTTPS, Add Auth Header, and Remove Security Headers. See the Rewrite Templates guide for details.

Creating a Rewrite

1. Navigate to the Rewrites view using the left navigation rail
2. Click Add Rewrite
3. Configure the match and action:

Match Criteria

Field	Description
URL Pattern	Regex pattern to match the request URL (e.g., https://api\.example\.com). Empty matches all traffic — use with care.
Method	HTTP method to match — leave empty for any
Phase	Apply on Request or Response (or both)

Escape regex metacharacters

The URL pattern and the URL rewrite pattern are both regular expressions, not glob/wildcard patterns. If you want to match a literal dot in a hostname, use \. — an unescaped . matches any character. For example, use https://api\.example\.com to match the literal host, not https://api.example.com.

Rewrite Actions

Action	Direction	Description
Set Header	Request / Response	Add or overwrite a header
Remove Header	Request / Response	Remove a specific header
URL Rewrite	Request	Replace part of the URL using a regex pattern and replacement string
Body Rewrite	Request / Response	Replace text in the body using a regex pattern and replacement string

The backend also supports two additional actions via the REST API and CLI that are not yet exposed in the web UI:

Action	Direction	Description
Map to URL (map_to_url)	Request	Replace the entire request URL with a fixed target
Map to File (map_to_file)	Response	Replace the response body with the contents of a local file

4. Click Save to activate the rewrite

Common Use Cases

Redirect API Calls to a Different Server

Map API calls from production to your local development server:

• Match: */api/* on production-server.com
• Action: Redirect URL to localhost:3000/api/*

Inject Authentication Headers

Add an authorization token to all API requests:

• Match: */api/*
• Action: Add Header Authorization: Bearer <your-token>

Replace Response Bodies

Swap out specific content in API responses for testing:

• Match: */api/config on Response
• Action: Replace Body with custom JSON configuration

Remove Security Headers for Testing

Strip Content-Security-Policy headers to test if your app works without them:

• Match: * on Response
• Action: Remove Header Content-Security-Policy

Force HTTPS to HTTP

Redirect HTTPS requests to HTTP for easier debugging:

• Match: https://*.example.com/*
• Action: Replace URL https:// → http://

Managing Rewrites

Enabling / Disabling

Each rewrite has a toggle switch. Disabled rewrites remain in your list but don't modify traffic. This lets you keep configurations ready and toggle them as needed.

Priority

If multiple rewrites match the same request, they're applied in order of priority (lower number = higher priority). Set the priority when creating or editing a rewrite.

Editing and Deleting

• Click any rewrite to edit its configuration
• Use the trash icon to delete a rewrite
• Rewrites are persisted across restarts

See also

• Rewrite Templates — pre-built rules for common scenarios
• Breakpoints — interactive, one-off modifications
• Mocks — return fake responses without hitting the server
• Scripting — programmatic transformations
• REST API reference — /api/rewrites endpoints