> ## Documentation Index > Fetch the complete documentation index at: https://docs.baseten.co/llms.txt > Use this file to discover all available pages before exploring further. # Create a run > Creates a Loops run with an associated sampler in the given session. ## OpenAPI ````yaml post /v1/loops/runs openapi: 3.1.0 info: description: REST API for management of Baseten resources title: Baseten management API version: 1.0.0 servers: - url: https://api.baseten.co security: - BearerAuth: [] paths: /v1/loops/runs: post: summary: Creates a Loops run description: Creates a Loops run with an associated sampler in the given session. requestBody: content: application/json: schema: $ref: '#/components/schemas/CreateLoopsRunRequestV1' required: true responses: '200': description: '' content: application/json: schema: $ref: '#/components/schemas/CreateLoopsRunResponseV1' x-codeSamples: - lang: bash source: |- curl --request POST \ --url https://api.baseten.co/v1/loops/runs \ --header "Authorization: Bearer $BASETEN_API_KEY" \ --data '{ "session_id": null, "base_model": null, "name": null, "max_seq_len": null, "seed": null, "path": "bt://loops:k4q95w5/weights/step-100", "reuse_from_session_id": null }' - lang: python source: |- import requests import os API_KEY = os.environ.get("BASETEN_API_KEY", "") url = "https://api.baseten.co/v1/loops/runs" headers = {"Authorization": f"Bearer {API_KEY}"} response = requests.request( "POST", url, headers=headers, json={'session_id': None, 'base_model': None, 'name': None, 'max_seq_len': None, 'seed': None, 'path': 'bt://loops:k4q95w5/weights/step-100', 'reuse_from_session_id': None} ) print(response.text) components: schemas: CreateLoopsRunRequestV1: properties: session_id: description: ID of the Loops session this run belongs to. title: Session Id type: string base_model: description: Base model ID (e.g. 'Qwen/Qwen3-8B'). title: Base Model type: string name: anyOf: - maxLength: 255 minLength: 1 type: string - type: 'null' default: null description: >- Optional display name for the run. Defaults to the base model name when omitted. title: Name max_seq_len: anyOf: - type: integer - type: 'null' default: null description: >- Maximum prompt length (in tokens) the run must handle. Set this to the longest training example you plan to send. Defaults to the maximum supported by the model configuration. title: Max Seq Len lora_rank: default: 64 description: LoRA rank. title: Lora Rank type: integer seed: anyOf: - type: integer - type: 'null' default: null description: Random seed for reproducibility. title: Seed scale_down_delay_seconds: default: 3600 description: >- Seconds of inactivity before the run scales to zero. Must be between 1 and 3600 (1 hour). Defaults to 3600. exclusiveMinimum: 0 maximum: 3600 title: Scale Down Delay Seconds type: integer replicas: default: 1 description: >- Number of data-parallel trainer replicas. Each replica is one full copy of the model's preset node group, so the trainer deployment runs (preset node_count * replicas) nodes (e.g. replicas=4 on a 4-node preset → 16 nodes, 4 DP workers). Must be a positive integer. Defaults to 1. minimum: 1 title: Replicas type: integer path: anyOf: - type: string - type: 'null' default: null description: >- Optional bt:// URI of an existing checkpoint to load weights from on startup. Form: bt://loops:/weights/. examples: - bt://loops:k4q95w5/weights/step-100 title: Path reuse_from_session_id: anyOf: - type: string - type: 'null' default: null description: >- Optional Loops session ID whose trainer deployment should be reused for this run, sharing the infrastructure across sessions instead of provisioning fresh. The named session must belong to the same team. Reuse is best-effort: if the prior deployment is stopped, failed, its sampler is unhealthy, or this run requests replicas != 1, a new deployment is provisioned instead. title: Reuse From Session Id required: - session_id - base_model title: CreateLoopsRunRequestV1 type: object CreateLoopsRunResponseV1: properties: run: $ref: '#/components/schemas/LoopsRunV1' required: - run title: CreateLoopsRunResponseV1 type: object LoopsRunV1: properties: id: description: The run ID. title: Id type: string session_id: description: The session ID this run belongs to. title: Session Id type: string deployment_id: description: The ID of the Loops deployment the run executes on. title: Deployment Id type: string name: description: The run's display name. title: Name type: string base_model: description: The HuggingFace base model the run is fine-tuning. title: Base Model type: string base_url: description: The run's base URL. title: Base Url type: string created_at: description: Time the run was created in ISO 8601 format format: date-time title: Created At type: string sampler: $ref: '#/components/schemas/LoopsSamplerV1' description: The sampler bound to this run. required: - id - session_id - deployment_id - name - base_model - base_url - created_at - sampler title: LoopsRunV1 type: object LoopsSamplerV1: properties: id: title: Id type: string base_url: title: Base Url type: string base_model: description: The HuggingFace base model the sampler is serving. title: Base Model type: string created_at: description: Time the sampler was created in ISO 8601 format format: date-time title: Created At type: string model_id: description: Hashid of the underlying Baseten model. title: Model Id type: string deployment_id: description: Hashid of the specific model deployment (version). title: Deployment Id type: string status: $ref: '#/components/schemas/LoopsSamplerStatusV1' description: The sampler's current status. required: - id - base_url - base_model - created_at - model_id - deployment_id - status title: LoopsSamplerV1 type: object LoopsSamplerStatusV1: description: The current status of a Loops sampler. properties: name: $ref: '#/components/schemas/DeploymentStatusV1' description: The current status of the Loops sampler. required: - name title: LoopsSamplerStatusV1 type: object DeploymentStatusV1: description: The status of a deployment. enum: - BUILDING - DEPLOYING - DEPLOY_FAILED - LOADING_MODEL - ACTIVE - UNHEALTHY - BUILD_FAILED - BUILD_STOPPED - DEACTIVATING - INACTIVE - FAILED - UPDATING - SCALED_TO_ZERO - WAKING_UP title: DeploymentStatusV1 type: string securitySchemes: BearerAuth: type: http scheme: bearer description: >- Send `Authorization: Bearer `. The legacy `Authorization: Api-Key ` scheme is also accepted. ````