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A dataset is a curated set of records for supervised fine-tuning. Each record is one agent run, reconstructed into a chat-with-tools trajectory ({messages, tools}) — the training target. There’s no separate “expected” answer: SFT learns from the trajectory itself.

Build a dataset

Datasets are built from your real runs. Create one, then add the traces worth training on.
1

Create a dataset

From Datasets, give it a name. Empty to start.
2

Add traces

Use the trace selector to filter your runs (by intent, status, cost, tools, and more), preview the matches, and add them. Each trace is reconstructed into a record with its full message + tool trajectory.

Judge quality before you train

A fine-tune is only as good as its data. bryel surfaces the dimensions that make or break an SFT set — in the dataset view and through bryel_inspect_dataset.
Balance
intent distribution
How records spread across intents. One intent dominating makes the model overfit it and forget the rest.
Redundancy
duplicate clusters
Near-identical inputs waste capacity and bias the model. bryel groups them so you can prune to a few exemplars.
Trajectory health
looping / errored
Runs that looped or errored teach the model bad behavior. They’re flagged so you can drop or repair them.
Length
token & step distribution
Records that exceed the fine-tune context window get truncated mid-trajectory; trivially short ones add no signal.
In the dataset view you can filter to duplicates or problematic records and prune them in place.

Export for training

Export a dataset to fine-tune JSONL — one {messages, tools} object per line, ready for a training run.
1

Export JSONL

From the dataset, choose Export JSONL — bryel streams the records to a file you can download. A coding agent can do the same with bryel_export_dataset, then poll bryel_export_status for the download URL.
2

Train

Feed the JSONL to your fine-tuning pipeline.

Build datasets from your editor

Connect a coding agent over the remote MCP to query, curate, and inspect datasets.