---
title: "Create Chat Session"
method: POST
path: "/v1/store/chat-sessions"
tags: ["store"]
---

# Create Chat Session

`POST /v1/store/chat-sessions`

## Request body

- CreateChatSessionRequest
  - `chat_session_id` string, nullable
  - `notebook_id` string, nullable
  - `notebook_path` string, nullable
  - `title` string, nullable
  - `workspace_id` string, nullable
  - `session_args` SessionArgs — Validated session-scoped args persisted on chat sessions as JSON. Every write validates through :func:`validated_session_args_patch`; fields are flat in storage, grouped here by role.
    - `collaborative` boolean
    - `model` string, nullable
    - `curiosity_level` string, nullable
    - `independence_level` string, nullable
    - `parallelism_level` string, nullable
    - `execution_mode` string, nullable
    - `environment_profile` string, nullable
    - `sandbox_environment` object, nullable
    - `compute_traits` object, nullable
    - `lease_id` string, nullable
    - `compute_assertion` object, nullable
    - `kernel_affinity` object, nullable
    - `rft_mode` boolean, nullable
    - `rft_deployment` string, nullable
    - `slack_icon_emoji` string, nullable
    - `attribution` string, nullable
    - `run_trigger` string, nullable
    - `kernel_actual_compute` object, nullable
    - `workspace_box_provider` string, nullable
    - `workspace_baseline` string[], nullable
    - `last_seq_at_api_call` integer, nullable
  - `ephemeral` boolean
  - `sandbox_environment` SandboxEnvironmentSpec — Per-request container image and data mounts for a sandbox.
    - `image_ref` string, nullable
    - `mounts` ObjectStoreMount[]
      - `uri` string, required
      - `mount_path` string, required
      - `read_only` boolean
    - `run_scope` string, nullable
  - `isolated_run` boolean, nullable

## Response `200`

Successful Response

- unknown

## Other responses

- `422` — Validation Error

## Changes

- **2026-09-18** `abf76937a751` — 4 info
  - added the new optional request property `session_args/anyOf[subschema #1: SessionArgs]/lease_id`
  - added the new optional request property `session_args/anyOf[subschema #1: SessionArgs]/run_trigger`
  - added the optional property `detail/items/ctx` to the response with the `422` status
  - added the optional property `detail/items/input` to the response with the `422` status
- **2026-09-15** `21910d3ae5d8` — 1 info
  - added the new optional request property `session_args/anyOf[subschema #1: SessionArgs]/collaborative`
- **2026-09-13** `9130e4640e24` — 1 info
  - added the new optional request property `session_args/anyOf[subschema #1: SessionArgs]/workspace_baseline`
- **2026-09-11** `b6d2db8786ed` — 1 info
  - added the new optional request property `session_args/anyOf[subschema #1: SessionArgs]/kernel_affinity`
- **2026-09-10** `3a8d4a28ae93` — 1 breaking, 1 info
  - removed `subschema #1` from the `session_args` request property `anyOf` list
  - added `#/components/schemas/SessionArgs` to the `session_args` request property `anyOf` list

[Full history](https://skmtc.dev/quadrillion/apis/quadrillion-cloud-api/changes/v1/store/chat-sessions/post.md)

---

[API](https://skmtc.dev/quadrillion/apis/quadrillion-cloud-api.md) · [All operations](https://skmtc.dev/quadrillion/apis/quadrillion-cloud-api/llms.txt) · [OpenAPI document](https://skmtc.dev/quadrillion/apis/quadrillion-cloud-api/revisions/d61e2ec5a271?raw)