---
title: "Chat"
method: POST
path: "/chat"
tags: ["chat"]
---

# Chat

`POST /chat`

## Query parameters

- `root` union, required
  - CustomProviderChatSearchParams — Chat against a stored custom provider record. The wire format of ``provider_id`` is a relay GlobalID (e.g. ``UHJvdmlkZXI6MTM=``). It is decoded to its integer node ID at parse time so downstream consumers don't need to know the GlobalID encoding.
    - `provider_type` 'custom', required
    - `provider_id` integer, required
    - `model_name` string, required
  - BuiltInProviderChatSearchParams — Chat against a Phoenix built-in provider. Credentials and connection details (base URL, Azure endpoint, AWS region) are resolved from the secret store first and the process environment second. ``openai_api_type`` is honoured by the OpenAI and Azure OpenAI branches; other providers ignore it.
    - `provider_type` 'builtin', required
    - `provider` 'OPENAI' | 'AZURE_OPENAI' | 'ANTHROPIC' | 'GOOGLE' | 'DEEPSEEK' | 'XAI' | 'OLLAMA' | 'AWS' | 'CEREBRAS' | 'FIREWORKS' | 'GROQ' | 'MOONSHOT' | 'PERPLEXITY' | 'TOGETHER', required
    - `model_name` string, required
    - `openai_api_type` 'chat_completions' | 'responses'

## Response `200`

Successful Response

- unknown

## Other responses

- `422` — Validation Error

## Changes

- **2026-05-07** `4714c409fd3d` — 1 info
  - endpoint added

[Change history](https://skmtc.dev/arize-ai/apis/arize-phoenix-rest-api/changes/chat/post.md)

---

[API](https://skmtc.dev/arize-ai/apis/arize-phoenix-rest-api.md) · [All operations](https://skmtc.dev/arize-ai/apis/arize-phoenix-rest-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/arize-ai/arize-phoenix-rest-api/revisions/4714c409fd3d/schema)