Observability for Cursor with Opik
The Cursor extension for Opik allows you to log all your Cursor conversations to Opik. Once they are available in Opik, you can easily review them and share them with your team.
Cursor does not expose an OpenTelemetry exporter for its chat, so the extension is the supported way to get Cursor sessions into Opik. If you want the other direction, letting Cursor read your traces, score outputs and run evaluations from chat, the extension registers the Opik MCP server for you; see the MCP Server Integration section on this page.
Opik shows you what Cursor did. If the question is where the tokens went and how to spend fewer of them, that is Cost Intelligence: every Cursor API call captured on the wire and attributed to system prompt, tools, MCP servers and user input, per user and per repository, with policy controls that typically cut spend by 15% to 30%. Only counts and metadata leave the machine, never content. It runs side by side with this extension.
Installation
You can also install the Cursor extension manually by navigating to the Extensions tab at the top of the file sidebar and search for Opik.
From there, simply click on the Install button.
Configuring the extension
In order to use the extension, you will need to configure your Opik API key. There are a few ways to do this:
Extension settings
Configuration file
The most straightforward way to configure the extension is to use the extension settings.
When you install the extension, you will see the following modal in the bottom left of your screen:
In this modal, click on Open Settings and paste your Opik API key in the Opik: Opik API Key field.
You can find your API key in the Opik dashboard.
Once the extension is installed, all your new Cursor conversations will be logged to Opik.
MCP server
To let Cursor’s agent read your traces, score outputs and run evaluations, connect the Opik MCP server. One command sets it up and installs the Opik skills:
Token usage and cost
Each logged conversation turn also records how many tokens it used and what it cost. You will see the model, the prompt and completion tokens, the cache read and write tokens, and an estimated cost on the LLM span of every trace.
These numbers come from Cursor itself, using the Cursor account you are already signed in to. You do not need a separate API key, and you do not need to be a team admin.
The token counts arrive a few seconds after the conversation is logged, so a trace may briefly appear without them. A turn that did not result in a billable request, such as one you cancelled, keeps its trace but has no usage attached.
To turn this off, set Opik: Usage Enrichment Enabled to false in the extension settings. Your
conversations are still logged, just without token counts or cost.
Viewing your conversations
Once the extension is installed and configured, all your conversations will be available in the cursor project in Opik. To
view the full conversation, you can navigate to the threads tab and click on any of the chats.
You can also review individual LLM responses by clicking on a trace in the traces tab. In the traces sidebar view, you can
see the full cursor event data in the metadata section.