The bdg cdp command provides direct access to the Chrome DevTools Protocol (CDP), enabling you to execute any of the 300+ methods across 53 domains.
Quick Start
# List all available CDP domains
bdg cdp --list
# Search for methods by keyword
bdg cdp --search cookie
# Describe a method's parameters and return types
bdg cdp Network.getCookies --describe
# Execute a method
bdg cdp Network.getCookies
bdg cdp Runtime.evaluate --params '{"expression":"document.title"}'
Syntax
bdg cdp [method] [options]
CDP method name in the format Domain.method (e.g., Network.getCookies, Page.navigate)Case-insensitive: network.getcookies works the same as Network.getCookies
Discovery Flags
Before executing methods, use these flags to explore the available API surface.
List Domains
Shows all 53 CDP domains with descriptions, command counts, and experimental status.
Example output:
{
"count": 53,
"domains": [
{
"name": "Network",
"description": "Network domain allows tracking network activities",
"commands": 48,
"events": 23,
"experimental": false
},
{
"name": "Page",
"description": "Actions and events related to the inspected page",
"commands": 42,
"events": 28,
"experimental": false
}
]
}
List Domain Methods
bdg cdp Network --list
bdg cdp Page --list
{
"domain": "Network",
"description": "Network domain allows tracking network activities",
"count": 48,
"methods": [
{
"name": "getCookies",
"fullName": "Network.getCookies",
"description": "Returns all browser cookies",
"parameterCount": 1,
"example": "bdg cdp Network.getCookies"
}
]
}
Search Methods
bdg cdp --search cookie
bdg cdp --search screenshot
bdg cdp --search performance
{
"query": "cookie",
"count": 5,
"methods": [
{
"name": "Network.getCookies",
"domain": "Network",
"method": "getCookies",
"description": "Returns all browser cookies",
"parameterCount": 1,
"example": "bdg cdp Network.getCookies"
},
{
"name": "Network.setCookie",
"domain": "Network",
"method": "setCookie",
"description": "Sets a cookie with the given cookie data",
"parameterCount": 1,
"example": "bdg cdp Network.setCookie --params '{...}'"
}
]
}
Describe Method
bdg cdp Network.getCookies --describe
bdg cdp Runtime.evaluate --describe
- Parameter names, types, and whether they’re required
- Return value types
- Usage examples
- Special behavior notes (for event-based methods)
Example output:
{
"type": "method",
"name": "Runtime.evaluate",
"domain": "Runtime",
"method": "evaluate",
"description": "Evaluates expression on global object",
"parameters": [
{
"name": "expression",
"type": "string",
"required": true,
"description": "Expression to evaluate"
},
{
"name": "returnByValue",
"type": "boolean",
"required": false,
"description": "Whether the result is expected to be a JSON object"
}
],
"returns": [
{
"name": "result",
"type": "RemoteObject",
"optional": false,
"description": "Evaluation result"
}
],
"example": {
"command": "bdg cdp Runtime.evaluate --params '{\"expression\":\"...\"}'",
"params": {
"expression": "..."
}
}
}
Execution
Simple Methods (No Parameters)
bdg cdp Network.getCookies
bdg cdp Page.getNavigationHistory
bdg cdp Runtime.getIsolateId
Methods with Parameters
Use --params with a JSON string:
bdg cdp Runtime.evaluate --params '{"expression":"document.title"}'
bdg cdp Page.navigate --params '{"url":"https://example.com"}'
bdg cdp DOM.querySelector --params '{"nodeId":1,"selector":"h1"}'
- Use single quotes around the JSON string to avoid shell escaping issues
- If the JSON contains single quotes, use double quotes outside and escape inner quotes
Error Handling
If a method name is not found, bdg suggests similar methods:
$ bdg cdp Network.getCookie
Error: Method 'Network.getCookie' not found
Did you mean:
- Network.getCookies
- Network.setCookie
- Network.deleteCookies
Use: bdg cdp Network --list (to see all Network methods)
Options
Method parameters as a JSON stringExample: --params '{"expression":"document.title"}'
List all domains (without method argument) or all methods in a domain (with domain argument)Examples:
bdg cdp --list - List all domainsbdg cdp Network --list - List all Network methods
Show method signature, parameters, and return typesExample: bdg cdp Network.getCookies --describe
Search methods by keywordExample: bdg cdp --search cookie
Event-Based Methods
Some CDP methods trigger asynchronous operations where results arrive via events rather than immediate responses. When these methods return empty results, bdg provides contextual hints.
Example:
$ bdg cdp Audits.checkContrast
{
"method": "Audits.checkContrast",
"result": {},
"hint": "This method triggers contrast analysis but results are sent via Audits.issueAdded events. Alternative: bdg dom eval with getComputedStyle() for direct contrast checking."
}
| Domain | Behavior | Alternative |
|---|
| Audits | Issues via Audits.issueAdded events | bdg dom eval with getComputedStyle() |
| Profiler | Data after Profiler.stop | Call start, perform actions, then stop |
| HeapProfiler | Events after takeHeapSnapshot | Collect events or use snapshots |
| Tracing | Data via Tracing.dataCollected | Call start, perform actions, then end |
| Overlay | Visual only, returns empty | Use Overlay.hideHighlight to clear |
--describe on these domains to see detailed notes about their behavior:
bdg cdp Audits --describe
Blocked Methods
Certain methods are blocked from direct execution because they return large binary data that can corrupt terminal sessions:
- Page.captureScreenshot - Use
bdg dom screenshot instead
Attempting to call blocked methods will show an error with the recommended alternative:
$ bdg cdp Page.captureScreenshot
Error: Page.captureScreenshot is blocked via raw CDP
Reason: Returns large base64 data that corrupts terminal sessions
Use: bdg dom screenshot [path]
Exit Codes
| Code | Meaning |
|---|
| 0 | Success |
| 81 | Invalid arguments (method not found, invalid JSON) |
| 83 | Resource not found (domain not found) |
| 102 | CDP timeout |
bdg dom - High-level DOM inspection and interactionbdg network - Network request inspectionbdg console - Console message inspection
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