---
title: "Start a simulation"
method: POST
path: "/simulations"
---

# Start a simulation

`POST /simulations`

Start a new simulation using a simulation case.

## Headers

- `Authorization` string, required

## Request body

- SimulationCreateIn — Input payload to start a simulation.
  - `simulation_case_id` string, uuid, required
  - `simulation_session_id` string, uuid, nullable
  - `target_agent_id` string, uuid, required
  - `custom_variables` object

## Response `200`

200

- StartSimulationResponse200
  - `status` string — Whether the request was successful.
  - `response` SimulationReadOut — Simulation details.
    - `simulation_id` string, uuid
    - `simulation_session_id` string, uuid
    - `simulation_case_id` string, uuid
    - `simulation_case_name` string, nullable
    - `simulation_case_prompt` string, nullable
    - `success_criteria` string[], nullable
    - `call_success_type` 'all' | 'any'
    - `persona_agent_id` string, uuid, nullable
    - `persona_phone_number` string, nullable
    - `target_agent_id` string, uuid
    - `agent_name` string, nullable
    - `agent_avatar_url` string, nullable
    - `target_phone_number` string, nullable
    - `target_call_id` string, nullable
    - `custom_variables` object, nullable
    - `status` 'in-progress' | 'completed' | 'failed'
    - `workspace_id` string
    - `created_at` string, date-time
    - `updated_at` string, date-time
    - `error_info` SimulationErrorInfo — Error information for failed simulations.
      - `message` string, required
      - `code` integer, required
      - `type` string, required
    - `recording_url` string, nullable
    - `timeline` TimelineItem[], nullable
      - `sender_type` string, nullable
      - `value` string, nullable
      - `type` string, nullable
      - `timestamp_datetime` string, date-time, nullable
      - `timestamp` string, nullable
    - `success_criteria_analysis` SimulationSuccessCriteriaAnalysis — Summary of the success criteria evaluation results.
      - `success` boolean, required
      - `evaluations` SimulationSuccessCriteriaEvaluation[], required
        - `success` boolean, required
        - `reasoning` string, required

## Other responses

- `400` — 400
- `404` — 404
- `422` — 422

---

[API](https://skmtc.dev/synthflow/apis/platform-api.md) · [All operations](https://skmtc.dev/synthflow/apis/platform-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/synthflow/platform-api/revisions/6976456ad422/schema)