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POST
Create an experiment and its setup

Authorizations

X-Auth-Token
string
header
required

Project API key for sending traces and accessing project-scoped resources. Format: sk-lw-... (no underscore). Obtain one by creating a project via the Admin API or the LangWatch UI.

Body

application/json
name
string

Name for the experiment. A draft name is picked when omitted.

Minimum string length: 1
state
object

Setup to start from. Omit for a blank workbench with one inline dataset.

Response

Experiment created

id
string
required

Identifier of the created experiment

slug
string
required

Slug to address the experiment by

version
number
required

Version of the saved setup, starting at 1

Last modified on August 24, 2026