---
title: Roo Code + custom endpoint — agent forks shouldn't cost frontier prices
description: Roo Code (a Cline fork) supports any OpenAI-compatible base URL. Here's the 2-minute config that routes through jusInfer and drops autonomous-edit bills 60-80% without giving up Roo's multi-mode workflow.
tldr: In Roo Code → Settings → API Configuration, pick "OpenAI Compatible". Set Base URL to https://api.jusinfer.com/v1, paste a jinf_ token, and use jusInfer-auto. All four modes (Code, Architect, Ask, Debug) keep their behavior — jusInfer picks the cheapest capable model per turn.
date: 2026-05-27
author: jusInfer
cluster: integration
tags: roo-code, vscode-agent, openai-compatible, custom-base-url, cost-optimization
---

# Roo Code + custom endpoint — fork the agent, not the bill

[Roo Code](https://roocode.com) is a Cline fork that added persistent multi-mode workflows (Code, Architect, Ask, Debug) and a richer prompt-customization surface. It's excellent for long-running refactors and architecture conversations — and like Cline, it'll happily burn through Claude tokens on default settings. Roo natively supports any OpenAI-compatible base URL, so you can route through jusInfer and keep all four modes working as designed.

## What you'll change

Two values in Roo Code's settings panel. No extension reinstall, no mode behavior change, no workflow change.

## Setup

### 1. Mint a jusInfer API key

Sign in at [jusinfer.com/login](https://jusinfer.com/login) with Google or Microsoft. Open [jusinfer.com/developer](https://jusinfer.com/developer) → **Keys** tab → **Mint key**. Copy the `jinf_…` token (shown once).

### 2. Configure Roo Code

Open Roo Code in VS Code → click the gear icon → **API Configuration**.

- **API Provider**: `OpenAI Compatible`
- **Base URL**: `https://api.jusinfer.com/v1`
- **API Key**: paste the `jinf_…` token
- **Model**: `jusInfer-auto`
- **Model Context Window**: leave at default (Roo auto-detects from the first response)

Save. That's it.

### 3. Verify

Open any project, hit **Code** mode, type `read package.json and tell me what this app does`. You should see a normal Roo response. Open the Roo output panel — request lines now show `api.jusinfer.com` instead of `api.anthropic.com`.

## Mode-by-mode notes

| Mode | What changes | What doesn't |
|---|---|---|
| **Code** | Picks a smaller model for "read file" steps, a stronger one for "rewrite this function" | Tool use, file edits, terminal commands |
| **Architect** | Routes long-context planning to a high-context model regardless of cost (it's the highest-leverage call in a session) | Plan-then-implement separation |
| **Ask** | Single-shot Q&A goes to a fast, cheap model — usually 10-15ms TTFT | Conversation persistence |
| **Debug** | Stack-trace analysis lands on a reasoning-capable model with `reasoning_effort=medium` by default | Test-run loop, breakpoint inspection |

## What if Roo's auto-detection picks the wrong context window?

Set it explicitly. In **Advanced Settings**, override `Context Window` to `200000` (DeepSeek v4 Pro's window, currently jusInfer's default upstream). If you later hit a model with a smaller window, jusInfer will route around it; the override just prevents Roo from truncating your prompt before the request leaves.

## Cost comparison — same 4-hour Roo session

| Setup | Approximate session cost | Notes |
|---|---|---|
| Roo + Claude Sonnet (direct) | $18-25 | Baseline; mixed-mode session, ~40 tool calls |
| Roo + GPT-4.1 (direct) | $14-19 | Cheaper input, comparable output |
| Roo + jusInfer-auto | $4-7 | Smaller model on tool-use steps; reasoning model only when needed |

(These are sample sessions, not benchmarks. Your numbers will vary with how much you bounce between Architect and Code modes.)

## What Roo doesn't lose

- **Multi-mode workflow** — all four modes route through the same endpoint; the mode switch is client-side
- **Custom instructions** — Roo's mode-level custom instructions go in the system prompt; jusInfer passes them through unchanged
- **Prompt history** — stored locally in your VS Code profile; not touched by the endpoint change
- **Approval flows** — Roo's "review before applying" toggles are client-side; unaffected

## When to stay on Roo's default provider

Two cases:
1. **Strict provider compliance** — your team has a contract with Anthropic or OpenAI that requires direct billing. jusInfer is a passthrough; the underlying provider sees jusInfer's account, not yours.
2. **Provider-specific features Roo doesn't abstract** — e.g. Claude's prompt caching headers, if Roo exposes them in a future release. As of today, all mode behaviors are abstractable through OpenAI-compatible calls.

## Switching back

Same gear icon, change **API Provider** back to your prior choice. No state is lost. jusInfer keys keep working until you revoke them — you can A/B between endpoints without churn.

## Further reading

- [Cline + custom endpoint](/blog/cline-custom-endpoint) — the parent project's setup
- [Custom agent harness on an OpenAI-compatible base URL](/blog/custom-agent-harness-openai-compatible) — what every harness needs
- [jusInfer API reference](/docs/api-reference) — every supported field including `reasoning_effort` and `thinking`