Advanced

network route intercepts matching requests through CDP's Fetch domain — no proxy, and no extension permissions. You can mock a fake response, rewrite the outgoing request, tamper with the real response, or simply block certain traffic. The verbs and fields mirror Playwright's conventions, so there's almost nothing to learn.

Three modes

Which mode a single network route rule falls into depends on which flags you pass. They each step in at a different moment:

Mock response

Pass flags like --body and the request is fulfilled directly — a fake response returns immediately and the real network request is never sent. Ideal for producing empty lists, permission states, or isolating the backend.

# Mock response (fulfill — the request never leaves the browser)
$ chrome-use network route "**/api/users" --body '{"users":[]}' --status 200 --content-type application/json
$ chrome-use network route "**/api/me" --body '{"vip":true}' --header X-From=mock

Rewrite the outgoing request

Pass --method, --set-body, --set-header, or --rewrite-url, and the request continues with your overrides (continue with overrides), after which the real response comes back as usual. This is how you inject a test auth header, replace the request body, or route traffic to staging.

# Rewrite the outgoing request (the real response still comes back)
$ chrome-use network route "**/api/save" --method POST --set-header Authorization="Bearer test"
$ chrome-use network route "**/api/save" --set-body '{"x":1}'          # replace the request body
$ chrome-use network route "**/v1/*" --rewrite-url https://staging.example.com/v1/thing

Edit the real response

Pass --edit-status, --edit-header, or --replace 'from=>to', and the request goes out normally; once the real response returns, you tamper with it, and the page sees the modified version. Perfect for forcing an endpoint into a 503 error state, or swapping one field in the response without touching the backend.

# Edit the real response (request sent, response returns, then modified)
$ chrome-use network route "**/api/me" --edit-status 503                # override the status code
$ chrome-use network route "**/api/me" --edit-header X-Env=test         # add/override a response header
$ chrome-use network route "**/api/me" --replace 'prod=>staging'        # substring replace in the real response body (repeatable)
$ chrome-use network route "**/api/me" --set-json data.user.vip=true     # structured edit of one JSON field in the response body

--set-json <dot.path>=<value> locates a field in the response body's JSON by a dot-separated path and creates or overwrites it — nested paths fill in the intermediate objects automatically. If the body isn't valid JSON, it falls back to a plain string replace, the same safe behavior as --replace, instead of failing on the parse error.

Block and scope by resource type

Use --abort to cut off a request outright. Any rule can be scoped with --resource-type to limit its reach and avoid catching other traffic by accident.

# Block completely
$ chrome-use network route "**/analytics" --abort

# Scope a rule to certain resource types
$ chrome-use network route "**/*.json" --abort --resource-type xhr,fetch

Observe and record traffic

Before rewriting, see clearly which requests are in flight. network requests lists captured traffic, and --clear starts recording fresh; network har records the whole session into a standard HAR file.

$ chrome-use network requests --clear        # clear and start capturing again
$ chrome-use network requests                # see which requests went out

$ chrome-use network har start               # record all traffic
# ... perform your actions ...
$ chrome-use network har stop /tmp/trace.har

Clean up rules

All route rules are persistent and stay in effect until you explicitly remove them. When you're done, use network unroute to drop them all at once so they don't affect later sessions.

$ chrome-use network unroute                 # remove all route rules

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