Mock Response

Chute can return mock data for matched HTTP/HTTPS requests. For decrypted HTTP/2 streams the mock response is answered locally without forwarding the request; for HTTP/1.1 requests (plain proxying and MitM HTTP/1.1) the request is still sent to the real server, and the real response is replaced with the mock data before it reaches the client. This is useful for testing, development, or blocking unwanted content with a custom response.

Mock rules are defined in the [Map Local] section.

Only one mock rule is applied per request — the first rule whose URL pattern matches.

Map Local Format

For serving mock responses from local files or with base64-encoded content:

[Map Local]
^https://example\.com/api.* data="/path/to/mock-response.json"
^https://example\.com/page.* data="/path/to/page.html" header="SGVhZGVyOiBWYWx1ZQ=="
^https://example\.com/pixel.* base64="R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7"

Notice: The URL regular expression must match the complete request URL, not just a substring of it. Patterns should usually end with .* so that URLs with any path and query string are matched.

Map Local Parameters

At least one of data= or base64= must be specified.

Notice: When parsing header=, all whitespace is stripped and each line must be exactly Key:Value with a single colon. Header values that themselves contain a colon (such as URLs) are silently dropped, and spaces inside values are lost.

Template Variables

When using data= or base64=, the response body supports template variable substitution:

Example mock response file (response.json):

{
    "requested_url": "{{ "{{url}}" }}",
    "host": "{{ "{{host}}" }}",
    "method": "{{ "{{method}}" }}"
}

Note: For HTTPS requests, MitM decryption must be enabled for the matching hostname. Mock rules for HTTPS traffic without MitM will be ignored.