---
title: "Call Start"
method: POST
path: "/call/start"
tags: ["Calls"]
---

# Call Start

`POST /call/start`

## Request body

- CallStartReq
  - `start` StartedCallSchemaForInsert, required
    - `project_id` string, required
    - `id` string, nullable
    - `op_name` string, required
    - `display_name` string, nullable
    - `trace_id` string, nullable
    - `parent_id` string, nullable
    - `thread_id` string, nullable
    - `turn_id` string, nullable
    - `started_at` string, date-time, required
    - `attributes` object, required
    - `inputs` object, required
    - `otel_dump` object, nullable
    - `wb_user_id` string, nullable — Do not set directly. Server will automatically populate this field.
    - `wb_run_id` string, nullable
    - `wb_run_step` integer, nullable

## Response `200`

Successful Response

- CallStartRes
  - `id` string, required
  - `trace_id` string, required

## Other responses

- `422` — Validation Error

---

[API](https://skmtc.net/wandb/apis/fastapi.md) · [All operations](https://skmtc.net/wandb/apis/fastapi/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/wandb/fastapi/versions/56745769989b/schema)