crux-mcp
Server Configuration
Describes the environment variables required to run the server.
| Name | Required | Description | Default |
|---|---|---|---|
| CRUX_API_KEY | Yes | Your Google Chrome UX Report API key. |
Instructions
Guidance the server publishes about itself, which clients place ahead of the tool catalog so the model reads it before choosing anything.
This server publishes no instructions, or was last inspected before Glama recorded them.
Capabilities
Features and capabilities supported by this server
Protocol revision2025-11-25
| Capability | Details |
|---|---|
| tools | {
"listChanged": false
} |
| prompts | {
"listChanged": false
} |
| resources | {
"subscribe": false,
"listChanged": false
} |
| experimental | {} |
Tools
Functions exposed to the LLM to take actions
| Name | Description |
|---|---|
| crux_recordA | Current p75 Core Web Vitals for an origin or a single URL. Pass EITHER origin (e.g. https://www.betterpic.io — covers the whole site) OR url (one page). form_factor is PHONE, DESKTOP, TABLET or ALL. Returns each metric's p75 with a good / needs-improvement / poor assessment, plus an overall core_web_vitals_pass. Set raw=true for the untouched API response. |
| crux_historyA | Weekly Core Web Vitals trend, up to 25 points, for charting or regression checks. Same origin / url / form_factor rules as crux_record. Pass metric to return just one series, e.g. largest_contentful_paint, interaction_to_next_paint, cumulative_layout_shift, first_contentful_paint, experimental_time_to_first_byte. |
| crux_compareA | Compare Core Web Vitals across several origins — yours against competitors. origins is a comma-separated list, e.g. "https://www.betterpic.io,https://www.aragon.ai,https://www.headshotpro.com". Returns one row per origin with the three Core Web Vitals and whether it passes. Origins with no CrUX record are reported rather than dropped silently. |
Prompts
Interactive templates invoked by user choice
| Name | Description |
|---|---|
No prompts | |
Resources
Contextual data attached and managed by the client
| Name | Description |
|---|---|
No resources | |
TDQS
Scored across 3 tools
Each tool targets a distinct use case: crux_record for current snapshot, crux_history for trends, crux_compare for multi-origin comparison. No overlap in purpose or output.
All tools share the crux_ prefix followed by a clear descriptive word (record, history, compare). The naming pattern is consistent and predictable.
With only three tools, the server is tightly scoped to Core Web Vitals data retrieval. Each tool covers a distinct need and none feel redundant or extraneous.
The server provides the essential CrUX operations: current performance, historical trend, and cross-origin comparison. No obvious gaps exist for its stated purpose.