The Dataset API makes it easy to upload, download, and manage the large datasets that you need for fine-tuning models. You can find more information in the official Dataset API specs.

💡 The examples in this guide refer to the Cohere Python SDK, which comes with some convenience methods, but most of the functionality can be accessed in any language using the HTTP API.


In this initial section, we'll cover some limitations in the Dataset API, and discuss Cohere's policy on data retention.

File Size Limits

There are certain limits to the files you can upload through the Dataset API, specifically:

  • A Dataset can be as large as 1.5GB
  • Organizations have up to 10GB of storage across all their users


You should also be aware of how Cohere handles data retention. This is the most important context:

  • Datasets get deleted 30 days after creation
  • You can also manually delete a dataset using co.delete_dataset

Dataset Creation

Datasets are created by uploading files, specifying both a name for the dataset and the dataset_type.

The file extension and file contents have to match the requirements for the selected dataset_type. See the table below to learn more about the supported dataset types.

The dataset name is useful when browsing the datasets you've uploaded. In addition to its name, each dataset will also be assigned a unique id when it's created.

Here is an example code snippet illustrating the process of creating a dataset, with both the name and the dataset_type specified.

my_dataset = co.create_dataset(
	data=open("./shakespeare.csv", "rb"),


Dataset Validation

Whenever a dataset is created, the data is validated asynchronously against the rules for the specified dataset_type . This validation is kicked off automatically on the backend, and must be completed before a dataset can be used with other endpoints.

Here's a code snippet showing how to check the validation status of a dataset you've created.

my_dataset.await_validation() # this will error if validation fails

Using Datasets for Fine-tuning

Once the dataset passes validation, it can be used to fine-tune a model. To do this properly, you must include at least five train examples per label.

In the example below, we will create a new dataset and upload an evaluation set using the optional eval_data parameter. We will then kick off a fine-tuning job using co.create_custom_model.

# create a dataset
my_dataset = co.create_dataset(
	data=open("./shakespeare.csv", "rb"),
  eval_data=open("./shakespeare-eval.csv", "rb")

# start training a custom model using the dataset

Dataset Types

When a dataset is created, the dataset_type field must be specified in order to indicate the type of tasks this dataset is meant for.

Datasets of type prompt-completion-finetune-input, for example, are expected to have entries with the fields prompt and completion, like so:

  "prompt": "Say the word fish"
	"completion": "fish"
  "prompt": "Count to three"
	"completion": "1, 2, 3"

The following table describes the types of datasets supported by the Dataset API:

Dataset TypeDescriptionSchemaRulesTask TypeStatusFile Types SupportedAre Metadata Fields Supported?Sample File
prompt-completion-finetune-inputCommand-style data with a prompt and completion.prompt:string completition:stringYou must include at least 32 unique, utf-8 encoded training examples. Only 16 are required if you've uploaded evaluation data.Generative Fine-tuningSupportedcsv and jsonlNomath_solver_total.json
single-label-classification-finetune-inputA file containing text and a single label (class) for each texttext:string label:stringYou must include 40 valid train examples,
with five examples per label. A label cannot be present in all examples
There must be 24 valid evaluation examples.
Classification Fine-tuningSupportedcsv and jsonlNoArt classification file
multi-label-classification-finetune-inputA file containing text and an array of label(s) (class) for each texttext:string label:list[string]You must include 40 valid train examples, with five examples per label
A label cannot be present in all examples. There must be 24 valid evaluation examples.
Classification Fine-tuningSupportedcsv and jsonlNon/a
reranker-finetune-inputA file containing queries and an array of passages relevant to the query. There must also be "hard negatives", passages semantically similar but ultimately not relevant.query:string relevant_passages:list[string] hard_negatives:list[string]There must be 256 train examples and at least 64 evaluation examples. There must be at least one relevant passage, with no overlap between relevant passage and hard negatives.Rerank Fine-tuningSupportedjsonlNotrain_valid.json
chat-finetune-inputA file containing conversationsmessages: list[Message]

- Message - role: text context: text
There must be two valid train examples and one valid evaluation example.Chat Fine-tuningIn progress/not supportedjsonlNotrain_celestial_fox.json

Downloading a dataset

Datasets can be fetched using its unique id. Note that the dataset name and id are different from each other; names can be duplicated, while ids cannot.

Here is an example code snippet showing how to fetch a dataset by its unique id.

# fetch the dataset by ID
my_dataset = co.get_dataset("<DATASET_ID>")

# print each entry in the dataset
for record in

# save the dataset as jsonl
# or save the dataset as csv

Deleting a dataset

Datasets are automatically deleted after 30 days, but they can also be deleted manually. Here's a code snippet showing how to do that: