---
title: "Update a runtime harness"
method: PUT
path: "/api/runtime-harnesses/{alias}"
tags: ["Runtimes"]
---

# Update a runtime harness

`PUT /api/runtime-harnesses/{alias}`

## Path parameters

- `alias` string, required

## Request body

- CreateRuntimeHarnessRequest
  - `alias` string, required
  - `api_spec` 'claude_managed_agents' | 'cursor' | 'gemini_antigravity' | 'elastic_agent_builder', required
  - `api_base` string, required
  - `api_key` string, required

## Response `200`

Updated

- RuntimeHarnessesResponse
  - `harnesses` RuntimeHarness[]
    - `alias` string
    - `api_spec` 'claude_managed_agents' | 'cursor' | 'gemini_antigravity' | 'elastic_agent_builder'
    - `display_name` string
    - `api_base` string
    - `is_default` boolean
    - `connected` boolean
    - `masked_api_key` string, nullable
    - `tools` object[]

## Other responses

- `401` — Unauthorized
- `404` — Harness not found

---

[API](https://skmtc.dev/litellm-agent-platform/apis/litellm-agent-platform-api.md) · [All operations](https://skmtc.dev/litellm-agent-platform/apis/litellm-agent-platform-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/litellm-agent-platform/litellm-agent-platform-api/revisions/92039c29a228/schema)