---
title: "List custom tool runtimes"
method: GET
path: "/v1/custom-tools/runtimes"
tags: ["custom_tools"]
---

# List custom tool runtimes

`GET /v1/custom-tools/runtimes`

Returns the supported custom tool runtimes (Python, JavaScript) with the exact entrypoint signature, required return shape, starter template, built-in modules, and auto-installable third-party packages for each. Read this before authoring `code` for create/update.

## Response `200`

Supported custom tool runtimes

- object — Supported custom tool runtimes, with the entrypoint signature, return contract, and available dependencies per language.
  - `data` object[], required
    - `language` string, required
    - `display_name` string, required
    - `file_extension` string, required
    - `package_manager` string, required
    - `entrypoint_signature` string, required
    - `return_contract` string, required
    - `starter_template` string, required
    - `builtin_modules` string[], required
    - `available_packages` string[], required

## Other responses

- `401` — Unauthorized
- `429` — Rate limit exceeded

---

[API](https://skmtc.net/conduit/apis/conduit-api.md) · [All operations](https://skmtc.net/conduit/apis/conduit-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/conduit/conduit-api/versions/3ad7e17f96ad/schema)