---
title: Tool Bridge
emoji: 🔧
colorFrom: blue
colorTo: purple
sdk: docker
app_port: 8080
pinned: false
short_description: OpenAI/Anthropic tool-calling bridge for non-tool upstreams
---

# newapi-tool-bridge

OpenAI / Anthropic compatible tool-calling bridge proxy.

Wraps an upstream API that lacks native tool calling (e.g. a ChatGPT reverse-proxy)
into an OpenAI-compatible endpoint that supports `tools` / `tool_choice` /
`parallel_tool_calls`, plus full Anthropic Messages API (`/v1/messages`) translation.

## Endpoints

- `GET /v1/models` — list models
- `POST /v1/chat/completions` — OpenAI Chat Completions
- `POST /v1/messages` — Anthropic Messages API
- `GET /health` — health check
- other paths — proxied to upstream

## Auth (this deployment)

Public Space, **bring-your-own-key**: `UPSTREAM_AUTH_HEADER` is unset, so the
upstream key you send in `Authorization: Bearer <key>` (or `x-api-key`) is passed
through to the upstream. No key is baked into this Space.

## Config (Space variables)

| var | meaning |
|-----|---------|
| `UPSTREAM_BASE_URL` | upstream root (no `/v1`) |
| `MODEL_MAP_JSON` | external model name → upstream model name |
| `PUBLIC_MODEL_IDS_JSON` | model ids returned by `/v1/models` |
| `NATIVE_TOOL_MODELS_JSON` | models with native tool calling (passthrough) |
| `ALLOW_UNMAPPED_MODEL_PASSTHROUGH` | pass unmapped model names through |

Virtual tool calling: for upstreams without native `tools`, the tool defs are
injected into the system prompt, the model's JSON output is parsed back into
standard `tool_calls`.