---
title: "Use Goose (Block) with a custom provider: 5-minute setup"
description: Block's open-source Goose agent toolkit accepts any OpenAI-compatible provider. Here's how to route it through jusCode for cheaper, model-agnostic coding without changing your goose-extensions or workflow.
tldr: Run `goose configure`, pick OpenAI as the provider, point host to https://api.juscode.co and paste a jcg_ token. Goose's tool-use loop keeps working exactly as before; per-call routing drops typical bills 60-80%.
date: 2026-05-26
author: jusCode
cluster: integration
tags: goose, block, openai-compatible, custom-provider, agent-toolkit, ai-coding
---

# Use Goose (Block) with a custom provider

[Goose](https://block.github.io/goose/) is Block's open-source agent toolkit, strong on extensions (called "goose-extensions"), tool-use, and giving you full control over the agent loop. It accepts any OpenAI-compatible provider, which makes pointing it at jusCode a 5-minute config change with immediate cost savings.

## The 5-minute setup

```sh
goose configure
```

When prompted:

```
? Which provider?
  ↳ OpenAI

? Host (without trailing slash)
  ↳ https://api.juscode.co

? API key
  ↳ jcg_your_key_here

? Model
  ↳ jusCode-auto
```

Goose stores this in `~/.config/goose/config.yaml`. Verify:

```yaml
GOOSE_PROVIDER__TYPE: openai
GOOSE_PROVIDER__HOST: https://api.juscode.co
GOOSE_PROVIDER__API_KEY: jcg_…
GOOSE_PROVIDER__MODEL: jusCode-auto
```

Done. Start a session:

```sh
goose session start
```

## Getting an API key

Sign in at [juscode.co/login](https://juscode.co/login) → [juscode.co/developer](https://juscode.co/developer) → **Keys** tab → **Mint key**. Copy the `jcg_…` token (shown once). Paste into the configure prompt above.

## What works

| Feature | Status |
|---|---|
| `goose session start` interactive loop | ✅ |
| Tool extensions (`goose-extensions`) | ✅ |
| Memory between sessions | ✅ |
| Custom system prompts | ✅ |
| Streaming responses | ✅ |
| Plan-then-execute mode | ✅ |
| Image inputs (vision) | ✅ auto-routes to vision-capable model |

## Pinning a specific model

`jusCode-auto` lets jusCode pick per call. If you want every Goose interaction to hit a specific upstream:

```yaml
GOOSE_PROVIDER__MODEL: anthropic/claude-sonnet-4.5
# or
GOOSE_PROVIDER__MODEL: nousresearch/hermes-4-405b
# or
GOOSE_PROVIDER__MODEL: openai/gpt-5
```

jusCode normalizes provider prefixes, so you don't need separate accounts at each upstream.

## Why Goose benefits from per-call routing

Goose sessions tend to be tool-heavy: the agent calls `developer__list_files`, then `developer__read_file`, then `developer__write_file`, then `developer__shell` to run tests. That's 4 LLM round-trips just to apply one edit and verify it. Most of those round-trips are tactical (parse a directory listing, propose a small edit) and don't need a frontier model.

jusCode's per-call routing sends the tactical steps to a small fast model (Qwen3 8B, Hermes 70B) and reserves the frontier model for steps that actually need reasoning (architect a refactor, debug a confusing failure). On real Goose workloads we see 60-80% cost reduction with no task-completion regression.

## Goose-extensions still work

If you have custom goose-extensions (Slack integration, internal API wrappers, custom tool sets), they keep working unchanged: extensions communicate via Goose's tool-call protocol, which is OpenAI-compatible, which is what jusCode speaks. No extension-side change required.

## Common gotchas

- **`HOST` is the base URL without `/v1`.** Goose appends `/v1/chat/completions` itself. So set `https://api.juscode.co`, not `https://api.juscode.co/v1`.
- **Streaming is on by default** in Goose. If you see "Connection closed by peer" mid-stream, that's network, not the gateway. Retry the session.
- **Goose retries failed tool calls** up to N times. If you hit `429 RATE_LIMIT` on a burst, either wait or raise the per-key rpm in your [dashboard](https://juscode.co/developer) → Tenant tab.

## Multi-engineer setup

Each engineer mints their own `jcg_` key via `/developer` (separate keys = per-user spend attribution). They each run `goose configure` once with their own key. The owner can set per-user monthly soft caps under the Tenant tab to prevent any one engineer's runaway loop from draining the team wallet.

## Setup checklist

1. Sign up at [juscode.co/login](https://juscode.co/login).
2. Mint a `jcg_` key at [/developer](https://juscode.co/developer) → Keys.
3. `goose configure` → OpenAI provider, host `https://api.juscode.co`, paste key.
4. `goose session start`, run a normal workflow.
5. Check spend on the [Usage tab](https://juscode.co/developer).
6. (Multi-engineer) set per-user caps under Tenant tab.

## Related reading

- [OpenAI-compatible drop-in (Cursor, Aider, Cline, Continue, Goose…)](/docs/openai-drop-in/)
- [Cline + custom endpoint](/blog/cline-custom-endpoint/)
- [Continue.dev custom model](/blog/continue-custom-model/)
- [The cheapest LLM API for coding agents in 2026](/blog/cheapest-llm-api-for-coding-2026/)

---

*Raw markdown: [/blog/goose-custom-provider.md](/blog/goose-custom-provider.md)*