---
title: "POST /applications/{applicationId}/sessions"
method: POST
path: "/applications/{applicationId}/sessions"
---

# POST /applications/{applicationId}/sessions

`POST /applications/{applicationId}/sessions`

Creates and starts a new session on the specified application. The application must be in the <code>STARTED</code> state or have <code>AutoStart</code> enabled, and have interactive sessions enabled. This operation is supported for EMR release 7.13.0 and later.

## Path parameters

- `applicationId` string, required

## Request body

- object
  - `clientToken` string, required — A unique, case-sensitive identifier that you provide to ensure the idempotency of the request. If you retry a request that completed successfully using the same client token, the server returns the successful response without performing the operation again.
  - `executionRoleArn` string, required — The execution role ARN for the session. Amazon EMR Serverless uses this role to access Amazon Web Services resources on your behalf during session execution.
  - `configurationOverrides` object — The configuration overrides for a session.
    - `runtimeConfiguration` Configuration[] — The runtime configuration for the session. Contains Spark configuration properties specified at session creation time.
      - `classification` string, required — The classification within a configuration.
      - `properties` unknown
      - `configurations` Configuration[] — A list of additional configurations to apply within a configuration object.
  - `tags` object — The tags to assign to the session.
  - `idleTimeoutMinutes` integer — The idle timeout in minutes for the session. After the session remains idle for this duration, Amazon EMR Serverless automatically terminates it.
  - `name` string — The optional name for the session.

## Response `200`

Success

- StartSessionResponse
  - `applicationId` string, required — The output contains the application ID on which the session was started.
  - `sessionId` string, required — The output contains the ID of the session.
  - `arn` string, required — The output contains the ARN of the session.

## Other responses

- `480` — ValidationException
- `481` — ResourceNotFoundException
- `482` — InternalServerException
- `483` — ConflictException
- `484` — ServiceQuotaExceededException

---

[API](https://skmtc.net/aws/apis/emr-serverless.md) · [All operations](https://skmtc.net/aws/apis/emr-serverless/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/aws/emr-serverless/versions/d7a4ce0af1b7/schema)