---
title: "Update custom tool definition."
method: PUT
path: "/ai_assistants/{assistant_id}/tool"
tags: ["AI Assistants"]
---

# Update custom tool definition.

`PUT /ai_assistants/{assistant_id}/tool`

## Request

- Base URL: `https://h2ogpte.genai.h2o.ai/api/v1`
- URL: `https://h2ogpte.genai.h2o.ai/api/v1/ai_assistants/{assistant_id}/tool`
- Auth: HTTP bearer
- TypeScript: <https://skmtc.dev/h2o/apis/h2ogpte-rest-api/docs/ai_assistants/:assistant_id/tool/put.ts> (a function with typed inputs; its response is checked against the schema)

## Path parameters

- `assistant_id` string, required

## Request body

- AiAssistantToolRequest
  - `custom_tool_definition` string, required

## Response `204`

No Content

## Other responses

- `401`: Unauthorized - Invalid or missing API key
- `default`: Unexpected error

## Changes

- **2026-11-06** `a82a117320f4`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/h2o/apis/h2ogpte-rest-api/changes/ai_assistants/:assistant_id/tool/put.md)

---

[API](https://skmtc.dev/h2o/apis/h2ogpte-rest-api.md) - [All operations](https://skmtc.dev/h2o/apis/h2ogpte-rest-api/llms.txt) - [OpenAPI document](https://skmtc.dev/h2o/apis/h2ogpte-rest-api/revisions/a82a117320f4?raw)