---
title: "Changes to Chat"
method: POST
path: "/v1/agent_sessions/{session_id}/chat"
---

# Changes to Chat

`POST /v1/agent_sessions/{session_id}/chat`

> Every recorded change to this endpoint, newest first.

## Timeline

Changed in 5 of 71 revisions.

- **2026-09-01** `b43e9d4f06e0` — 1 info
- **2026-08-28** `4016becf04d6` — 1 info
- **2026-08-25** `e4bf71c6ae16` — 1 breaking, 13 info
- **2026-08-21** `6107b5235c74` — 1 warning, 2 info
- **2026-08-11** `881c8eca3876` — 1 info

## Changes

- **2026-09-01** `b43e9d4f06e0` — 1 info
  - added the new optional request property `credentials`
- **2026-08-28** `4016becf04d6` — 1 info
  - added the new optional request property `message/anyOf[subschema #1: PhoenixUIMessage]/parts/items/anyOf[subschema #2: ReasoningUIPart]/id`
- **2026-08-25** `e4bf71c6ae16` — 1 breaking, 13 info
  - removed `#/components/schemas/ProjectContext, #/components/schemas/TraceContext, #/components/schemas/SessionContext, #/components/schemas/PromptContext, #/components/schemas/PromptVersionContext, #/components/schemas/AgentSpanContext, #/components/schemas/PlaygroundContext, #/components/schemas/CodeEvaluatorContext, #/components/schemas/LlmEvaluatorContext, #/components/schemas/DatasetContext` from the `contexts/items/` request property `oneOf` list
  - added the new optional request property `message/anyOf[subschema #1: PhoenixUIMessage]/metadata/anyOf[subschema #1: MessageMetadata]/phoenix/anyOf[subschema #1]/oneOf[subschema #2: PhoenixUserMessageMetadata]/editPermission`
  - added the new optional request property `message/anyOf[subschema #1: PhoenixUIMessage]/metadata/anyOf[subschema #1: MessageMetadata]/phoenix/anyOf[subschema #1]/oneOf[subschema #2: PhoenixUserMessageMetadata]/uiContexts`
  - mapped value for discriminator key `code_evaluator` changed from `#/components/schemas/CodeEvaluatorContext` to `#/components/schemas/CodeEvaluatorUIContext` for `contexts/items/` request property
  - mapped value for discriminator key `dataset` changed from `#/components/schemas/DatasetContext` to `#/components/schemas/DatasetUIContext` for `contexts/items/` request property
  - mapped value for discriminator key `llm_evaluator` changed from `#/components/schemas/LlmEvaluatorContext` to `#/components/schemas/LlmEvaluatorUIContext` for `contexts/items/` request property
  - mapped value for discriminator key `playground` changed from `#/components/schemas/PlaygroundContext` to `#/components/schemas/PlaygroundUIContext` for `contexts/items/` request property
  - mapped value for discriminator key `project` changed from `#/components/schemas/ProjectContext` to `#/components/schemas/ProjectUIContext` for `contexts/items/` request property
  - mapped value for discriminator key `prompt` changed from `#/components/schemas/PromptContext` to `#/components/schemas/PromptUIContext` for `contexts/items/` request property
  - mapped value for discriminator key `prompt_version` changed from `#/components/schemas/PromptVersionContext` to `#/components/schemas/PromptVersionUIContext` for `contexts/items/` request property
  - mapped value for discriminator key `session` changed from `#/components/schemas/SessionContext` to `#/components/schemas/SessionUIContext` for `contexts/items/` request property
  - mapped value for discriminator key `span` changed from `#/components/schemas/AgentSpanContext` to `#/components/schemas/SpanUIContext` for `contexts/items/` request property
  - mapped value for discriminator key `trace` changed from `#/components/schemas/TraceContext` to `#/components/schemas/TraceUIContext` for `contexts/items/` request property
  - added `#/components/schemas/ProjectUIContext, #/components/schemas/TraceUIContext, #/components/schemas/SessionUIContext, #/components/schemas/PromptUIContext, #/components/schemas/PromptVersionUIContext, #/components/schemas/SpanUIContext, #/components/schemas/PlaygroundUIContext, #/components/schemas/CodeEvaluatorUIContext, #/components/schemas/LlmEvaluatorUIContext, #/components/schemas/DatasetUIContext` to the `contexts/items/` request property `oneOf` list
- **2026-08-21** `6107b5235c74` — 1 warning, 2 info
  - added the new `agent_session_tool_approvals_conflict` enum value to the `code` response property for the response status `409`
  - added the new optional request property `toolApprovals`
  - request property `contexts/items/oneOf[subschema #12: GraphQLContext]/` deprecated
- **2026-08-11** `881c8eca3876` — 1 info
  - endpoint added

---

[Operation](https://skmtc.dev/arize-ai/apis/arize-phoenix-rest-api/docs/v1/agent_sessions/:session_id/chat/post.md) · [API](https://skmtc.dev/arize-ai/apis/arize-phoenix-rest-api.md) · [Page](https://skmtc.dev/arize-ai/apis/arize-phoenix-rest-api/changes/v1/agent_sessions/:session_id/chat/post)