> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://www.comet.com/docs/opik/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://www.comet.com/docs/opik/_mcp/server.

# Ollie

With **Ollie** and `opik connect`, Opik becomes the place you actually fix it. Opik is no longer just a place to watch what your agent did. Ask a question about any trace, let Ollie read your code, have it edit the file, rerun your agent, and verify the fix with a test suite — all without leaving the browser.

![](https://fdr-prod-docs-files-public.s3.us-east-1.amazonaws.com/opik.docs.buildwithfern.com/1d4a44055acb6ac2a29483a6c04a5cbee1cf77c43f6e01928e55796d1c9e0b98/img/v2/ollie/hero.png?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6KXJSKKNFOCF7G4B%2F20260921%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20260921T234544Z&X-Amz-Expires=604800&X-Amz-Signature=7c28963bd583f0492998aa95bede7db78e6bf9a882158df37a38067ab4c7554a&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)

## Meet Ollie

Ollie is a conversational AI assistant built into Opik. It lives next to every trace, dataset, experiment, and prompt you've logged — and when you pair your local project with `opik connect`, Ollie can also read your source files, run your agent, and propose code changes. One assistant, full context: your data on one side, your code on the other.

## What Ollie can do

#### Investigate any trace

Ollie reads full span trees, identifies root causes, and compares failing
runs to successful ones. Ask *"why did the final answer ignore the context?"*
and get a grounded answer, not a guess.

#### Connect to your code

Pair your local project with `opik connect` and Ollie gains the ability to
read your source files, propose edits (with your approval), and rerun your
agent with the changes in place.

#### Close the loop

Every fix becomes a test. Ollie can add a failing trace to a test suite,
then trigger the suite against your updated agent to confirm the regression
is gone.

#### Works across your workspace

Traces, threads, datasets, experiments, prompts — Ollie queries across all
of them in a single conversation. No tab-switching, no manual stitching.

## From debugging to improvement

The real workflow — and the reason Ollie exists — is the full loop from *"something looks wrong"* to *"it's fixed and it won't regress."* Here's what that looks like in Opik:

### Spot a failing trace

Start where every debugging session starts: a trace that looks wrong. Filter by error status, low feedback score, or latency spike.

### Ask Ollie what went wrong

Open Ollie from the trace view. Describe what looks off — *"the model ignored the retrieved context"*, *"the tool call returned empty"* — and Ollie walks the span tree to find the cause.

![](https://fdr-prod-docs-files-public.s3.us-east-1.amazonaws.com/opik.docs.buildwithfern.com/cc6e36d7e4c5c970af552a48767c8d9f24ea0559095b6899fe8f9d3c1c72ca8f/img/v2/ollie/step-2-ask-ollie.png?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6KXJSKKNFOCF7G4B%2F20260921%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20260921T234544Z&X-Amz-Expires=604800&X-Amz-Signature=5a275594c2d0eb1641b2bf9827e6a783e889167bbd6cb99f80ef7d1763bbe405&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)

### Let Ollie read your code

Once Ollie identifies *where* the bug lives, it asks to read the relevant source file. With `opik connect` running on your machine, it has secure access to the files in your project — and shows you exactly what it's looking at.

### Approve the fix

Ollie proposes a change. You see the diff, approve it, and the file is updated on your machine. Nothing happens without your click.

![](https://fdr-prod-docs-files-public.s3.us-east-1.amazonaws.com/opik.docs.buildwithfern.com/2692e7aa086d5961b10c3182c64eb4e1158550828b201e025c059da52dde6f87/img/v2/ollie/step-4-suggested-fix.png?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6KXJSKKNFOCF7G4B%2F20260921%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20260921T234544Z&X-Amz-Expires=604800&X-Amz-Signature=fd504f722aa32a1772ef6b1316d1a10ba25fae1cbbc5ee5728b8738ee8e703f1&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)

### Rerun the agent from Opik

With the fix applied locally, Ollie reruns your agent through `opik connect` using the same inputs from the original failing trace. The new trace streams back into Opik in real time.

### Verify with a test suite

Ask Ollie to add the original trace to a test suite as a regression case, then run the suite against the updated agent. You get a pass/fail summary — and a test that will catch the bug if it ever comes back.

![](https://fdr-prod-docs-files-public.s3.us-east-1.amazonaws.com/opik.docs.buildwithfern.com/5257da8decefa09cd73ff47ae9fdf21836e406355bc48a972099dbc230ab0417/img/v2/ollie/step-6-eval-verification.png?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6KXJSKKNFOCF7G4B%2F20260921%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20260921T234544Z&X-Amz-Expires=604800&X-Amz-Signature=943967c04da2ba44369a2409af9e4f4afcef5947302f15d6bf5587a4e40fc220&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)

## Get started with Ollie

### Run `opik connect` in your agent folder

From the root of your agent project, run:

```bash
opik connect --project <project-name>
```

That's it. `opik connect` pairs your local project with Opik, and Ollie takes care of the rest — discovering your entrypoints, running your agent, and proposing code changes.

### Chat with Ollie

Open Ollie from anywhere in the Opik UI and start asking. Traces, code, reruns, evaluations — it's all one conversation from here.

`opik connect` is opt-in and scoped to the session it's launched in. Ollie
can only read and edit files in the project you connect, and every write
operation requires your explicit approval.

## Next steps

#### [Debugging agents with Ollie](/tracing/debug-agents)

The tactical guide to the debug-fix-verify loop, with example prompts.

#### [Agent playground](/development/agent-playground)

Everything about `opik connect` — how it discovers and runs your agent.

#### [Test suites](/evaluation/overview)

Build the regression net Ollie will populate for you.

#### [MCP server](/mcp-server)

The same loop from your own editor: connect your AI coding assistant to Opik.