Yes, you can append to an existing dataset via the REST API using the POST /v1/datasets/upload endpoint with the action parameter set to "append". The request body must include the dataset name and the new examples to add, either as JSON or multipart/form-data. This allows you to add new examples to an existing dataset, not just create a new one. See the API details and example payloads in the <https://docs.arize.com/phoenix/sdk-api-reference/datasets#react-aria-%3ARd6pkd9uucqfkvfaH2%3A|official documentation> and <https://github.com/Arize-ai/phoenix/blob/main/src/phoenix/server/api/routers/v1/datasets.py|source code>.
Would you like a code example or more details on the request format?
Sources:
- <https://docs.arize.com/phoenix/sdk-api-reference/datasets#react-aria-%3ARd6pkd9uucqfkvfaH2%3A|Phoenix SDK API Reference: Datasets>
- <https://github.com/Arize-ai/phoenix/blob/main/src/phoenix/server/api/routers/v1/datasets.py|phoenix/server/api/routers/v1/datasets.py>
