> ## Documentation Index
> Fetch the complete documentation index at: https://docs.caylex.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Polar Signals

> AI-driven performance insights for developers

The Polar Signals MCP Server brings AI-powered performance engineering to your Caylex projects, enabling AI agents to directly interact with real production profiling data. Rather than manually interpreting flame graphs, agents can answer natural language questions like 'What are the main CPU bottlenecks?' or 'Which functions consume the most memory?' by querying actual profiles from Polar Signals Cloud. The server provides tools to discover projects, profile types, metadata labels, and label values, as well as execute PromQL-based profile queries for precise, filtered analysis. This makes performance optimization workflows — spanning CPU profiling, memory allocation analysis, and bottleneck identification — accessible through conversational AI interactions within Caylex Navigators.

<Warning>
  **Prerequisites:**

  * An active Polar Signals Cloud account with at least one project containing profiling data.
  * Authentication credentials obtainable from the 'AI' section of the Polar Signals dashboard.
</Warning>

<Note>
  **Important API details:**

  * Profile queries use PromQL syntax, so agents must construct valid PromQL expressions when calling the get\_profile tool (e.g., filtering by labels like app\_kubernetes\_io\_name).
  * Agents should first call get\_projects, then profile\_types, then labels/values in sequence to discover the correct query parameters before executing a get\_profile query.
  * Access to profiling data is scoped to the projects your authenticated Polar Signals account has been granted access to.
</Note>

## Server Details

| Property        | Value                                                                          |
| --------------- | ------------------------------------------------------------------------------ |
| **Transport**   | Streamable HTTP                                                                |
| **Server Type** | External                                                                       |
| **Endpoint**    | [https://api.polarsignals.com/api/mcp/](https://api.polarsignals.com/api/mcp/) |
| **Categories**  | API Tools & Services, Development & DevOps                                     |

## Authentication

This server supports the following authentication method:

### Header Authentication

This server authenticates via HTTP headers. During the server onboarding flow, you will be prompted to confirm the required headers. Note that you do not provide the values for the headers during the server on-boarding.
Header values are provided by the users during the [Auth Link](/auth/auth-links) flow.

## Getting Started

<Steps>
  <Step title="Add the server">
    Navigate to the **Server Library** and click on the **New Server** button. Find **Polar Signals** in the Caylex Catalog.
  </Step>

  <Step title="Server Onboarding flow">
    Go through the server onboarding flow.
  </Step>

  <Step title="Use in a project">
    Add the server to a [project](https://app.caylex.dev/projects) by configuring project connections. Its tools are now available to any agents connected to that project.
  </Step>
</Steps>

## Related Servers

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## References

<CardGroup cols={1}>
  <Card title="https://www.polarsignals.com/docs/mcp" href="https://www.polarsignals.com/docs/mcp" icon="arrow-up-right-from-square" />

  <Card title="https://www.polarsignals.com/blog/posts/2025/07/17/the-mcp-for-performance-engineering/" href="https://www.polarsignals.com/blog/posts/2025/07/17/the-mcp-for-performance-engineering/" icon="arrow-up-right-from-square" />
</CardGroup>