DevTools protocol interception, blocking & modification of requests

third_party/WebKit/Source/core/inspector/browser_protocol.json

 {
     "version": { "major": "1", "minor": "2" },
     "domains": [{
         "domain": "Inspector",
         "experimental": true,
         "types": [],
         "commands": [
             {
                 "name": "enable",
                 "description": "Enables inspector domain notifications."
@@ skipping 1104 matching lines @@
                 "id": "LoaderId",
                 "type": "string",
                 "description": "Unique loader identifier."
             },
             {
                 "id": "RequestId",
                 "type": "string",
                 "description": "Unique request identifier."
             },
             {
+                "id": "InterceptionId",
+                "type": "string",
+                "description": "Unique intercepted request identifier."
+            },
+            {
+                "id": "ErrorReason",
+                "type": "string",
+                "enum": ["Failed", "Aborted", "TimedOut", "AccessDenied", "ConnectionClosed", "ConnectionReset", "ConnectionRefused", "ConnectionAborted", "ConnectionFailed", "NameNotResolved", "InternetDisconnected", "AddressUnreachable"],
+                "description": "Network level fetch failure reason."
+            },
+            {
                 "id": "Timestamp",
                 "type": "number",
                 "description": "Number of seconds since epoch."
             },
             {
                 "id": "Headers",
                 "type": "object",
                 "description": "Request / response headers as keys / values of JSON object."
             },
             {
@@ skipping 363 matching lines @@
             {
                 "name": "getCertificate",
                 "description": "Returns the DER-encoded certificate.",
                 "parameters": [
                     { "name": "origin", "type": "string", "description": "Origin to get certificate for." }
                 ],
                 "returns": [
                     { "name": "tableNames", "type": "array", "items": { "type": "string" } }
                 ],
                 "experimental": true
+            },
+            {
+                "name": "enableRequestInterception",
+                "parameters": [
+                    { "name": "enabled", "type": "boolean", "description": "Whether or not HTTP requests should be intercepted and Network.requestIntercepted events sent." }
+                ],
+                "experimental": true
+            },
+            {
+                "name": "continueInterceptedRequest",
+                "description": "Response to Network.requestIntercepted which either modifies the request to continue with any modifications, or blocks it, or completes it with the provided response bytes. If a network fetch occurs as a result which encounters a redirect an additional Network.requestIntercepted event will be sent with the same InterceptionId.",
+                "parameters": [
+                    { "name": "interceptionId", "$ref": "InterceptionId" },
+                    { "name": "errorReason", "$ref": "ErrorReason", "optional": true, "description": "If set this causes the request to fail with the given reason." },
+                    { "name": "rawResponse", "type": "string", "optional": true, "description": "If set the requests completes using with the provided base64 encoded raw response, including HTTP status line and headers etc..." },
+                    { "name": "url", "type": "string", "optional": true, "description": "If set the request url will be modified in a way that's not observable by page." },
+                    { "name": "method", "type": "string", "optional": true, "description": "If set this allows the request method to be overridden."},
+                    { "name": "postData", "type": "string", "optional": true, "description": "If set this allows postData to be set."},
+                    { "name": "headers", "$ref": "Headers", "optional": true, "description": "If set this allows the request headers to be changed."}
+                ],
+                "experimental": true
             }
         ],
         "events": [
             {
                 "name": "resourceChangedPriority",
                 "description": "Fired when resource loading priority is changed",
                 "parameters": [
                     { "name": "requestId", "$ref": "RequestId", "description": "Request identifier." },
                     { "name": "newPriority", "$ref": "ResourcePriority", "description": "New priority" },
                     { "name": "timestamp", "$ref": "Timestamp", "description": "Timestamp." }
@@ skipping 140 matching lines @@
                 "name": "eventSourceMessageReceived",
                 "description": "Fired when EventSource message is received.",
                 "parameters": [
                     { "name": "requestId", "$ref": "RequestId", "description": "Request identifier." },
                     { "name": "timestamp", "$ref": "Timestamp", "description": "Timestamp." },
                     { "name": "eventName", "type": "string", "description": "Message type." },
                     { "name": "eventId", "type": "string", "description": "Message identifier." },
                     { "name": "data", "type": "string", "description": "Message content." }
                 ],
                 "experimental": true
+            },
+            {
+                "name": "requestIntercepted",
+                "description": "Details of an intercepted HTTP request, which must be either allowed, blocked, modified or mocked.",
+                "parameters": [
+                    { "name": "InterceptionId", "$ref": "InterceptionId", "description": "Each request the page makes will have a unique id, however if any redirects are encountered while processing that fetch, they will be reported with the same id as the original fetch." },
+                    { "name": "request", "$ref": "Request" },
+                    { "name": "redirectHeaders", "$ref": "Headers", "optional": true, "description": "HTTP response headers, only sent if a redirect was intercepted." },
+                    { "name": "redirectStatusCode", "type": "integer", "optional": true, "description": "HTTP response code, only sent if a redirect was intercepted." },
+                    { "name": "redirectUrl", "optional": true, "type": "string", "description": "Redirect location, only sent if a redirect was intercepted."}
+                ],
+                "experimental": true 
             }
         ]
     },
     {
         "domain": "Database",
         "experimental": true,
         "types": [
             {
                 "id": "DatabaseId",
                 "type": "string",
@@ skipping 3012 matching lines @@
                 "parameters": [
                     { "name": "windowId", "$ref": "WindowID", "description": "Browser window id." }
                 ],
                 "returns": [
                     { "name": "bounds", "$ref": "Bounds", "description": "Bounds information of the window. When window state is 'minimized', the restored window position and size are returned." }
                 ]
             }
         ]
     }]
 }