---
title: "Changes to Send message"
method: POST
path: "/session/{sessionID}/message"
---

# Changes to Send message

`POST /session/{sessionID}/message`

> Every recorded change to this operation, newest first.

## Timeline

Changed in 7 of 69 revisions.

- **2026-02-14** `9df3a7d5f839`: 5 warning, 1 info
- **2026-02-12** `7eb1c31fb938`: 3 info
- **2026-02-11** `8f23f1074f57`: 2 info
- **2026-02-09** `3e70f65f33fa`: 1 info
- **2026-02-06** `73bbed0ce3ce`: 1 info
- **2026-01-15** `840036baecaf`: 2 info
- **2026-01-04** `58e0e517471e`: 3 info

## Changes

- **2026-02-14** `9df3a7d5f839`: 5 warning, 1 info
  - removed the request property `format`
  - removed the optional property `info/structured` from the response with the `200` status
  - removed the optional property `info/tokens/total` from the response with the `200` status
  - removed the optional property `info/variant` from the response with the `200` status
  - removed the optional property `parts/items/anyOf[#/components/schemas/StepFinishPart]/tokens/total` from the response with the `200` status
  - removed `#/components/schemas/StructuredOutputError, #/components/schemas/ContextOverflowError` from the `info/error` response property `anyOf` list for the response status `200`
- **2026-02-12** `7eb1c31fb938`: 3 info
  - added the new optional request property `format`
  - added the optional property `info/structured` to the response with the `200` status
  - added `#/components/schemas/StructuredOutputError` to the `info/error` response property `anyOf` list for the response status `200`
- **2026-02-11** `8f23f1074f57`: 2 info
  - added the optional property `info/tokens/total` to the response with the `200` status
  - added the optional property `parts/items/anyOf[#/components/schemas/StepFinishPart]/tokens/total` to the response with the `200` status
- **2026-02-09** `3e70f65f33fa`: 1 info
  - added `#/components/schemas/ContextOverflowError` to the `info/error` response property `anyOf` list for the response status `200`
- **2026-02-06** `73bbed0ce3ce`: 1 info
  - added the optional property `info/variant` to the response with the `200` status
- **2026-01-15** `840036baecaf`: 2 info
  - added the new optional request property `parts/items/anyOf[#/components/schemas/SubtaskPartInput]/model`
  - added the optional property `parts/items/anyOf[subschema #2]/model` to the response with the `200` status
- **2026-01-04** `58e0e517471e`: 3 info
  - added `#/components/schemas/ResourceSource` to the `parts/items/anyOf[#/components/schemas/FilePartInput]/source` request property `anyOf` list
  - added `#/components/schemas/ResourceSource` to the `parts/items/anyOf[#/components/schemas/FilePart]/source` response property `anyOf` list for the response status `200`
  - added `#/components/schemas/ResourceSource` to the `parts/items/anyOf[#/components/schemas/ToolPart]/state/anyOf[#/components/schemas/ToolStateCompleted]/attachments/items/source` response property `anyOf` list for the response status `200`

---

[Operation](https://skmtc.dev/martian-engineering/apis/voltcode/docs/session/:sessionID/message/post.md) - [API](https://skmtc.dev/martian-engineering/apis/voltcode.md) - [Page](https://skmtc.dev/martian-engineering/apis/voltcode/changes/session/:sessionID/message/post)