OpenCode

Use Fusion Model with OpenCode.

Fusion configuration

Use a FUMO Dashboard key for an account registered and funded online.

Parameter	Value
Base URL	`https://capi.fumolab.ai/api/fusion/v1`
Available model IDs	`fusion-max-2.0`, `fusion-max-1.0`, `fusion-code-1.0`
API protocol	OpenAI Chat Completions API

What is OpenCode?

OpenCode↗ is an open-source coding agent available in the terminal and as a desktop application. It supports custom providers, project-aware coding workflows, multiple sessions, and language-server integration.

Fusion connects through OpenCode's OpenAI-compatible Chat Completions adapter.

Quick start

Step 1: Install OpenCode

Install OpenCode using its install script:

curl -fsSL https://opencode.ai/install | bash

For npm, Homebrew, Windows, and other installation methods, see the OpenCode installation guide↗.

Step 2: Get your FUMO API key

Follow Getting started for online self-service accounts (see Enterprise onboarding for enterprise accounts) to create and store your API key. If you use FUMO and have a sales representative, enter their Sales Code at signup or bind it later as described in Console and account.

Step 3: Add your Fusion credential

Start OpenCode in your project:

cd /path/to/your/project
opencode

Run /connect, scroll to Other, and enter:

Provider ID: fumo
API key:     your FUMO API key

The provider ID must be fumo so it matches the configuration below.

Step 4: Configure the provider

Create or update opencode.json in your project:

{
  "$schema": "https://opencode.ai/config.json",
  "provider": {
    "fumo": {
      "npm": "@ai-sdk/openai-compatible",
      "name": "FUMO",
      "options": {
        "baseURL": "https://capi.fumolab.ai/api/fusion/v1"
      },
      "models": {
        "fusion-code-1.0": {
          "name": "Fusion Code"
        },
        "fusion-max-2.0": {
          "name": "Fusion Max 2.0"
        },
        "fusion-max-1.0": {
          "name": "Fusion Max"
        }
      }
    }
  }
}

@ai-sdk/openai-compatible keeps this configuration on /chat/completions. Fusion also exposes /responses; OpenCode uses @ai-sdk/openai for providers configured on that endpoint.

Step 5: Select Fusion Code

Run:

/models

Choose FUMO, then Fusion Code. Your OpenCode requests will now use fusion-code-1.0.

Choose a model ID

Use /models at any time to switch between the model IDs authorized for your key:

Fusion Code — the default choice for coding and software-agent workflows.
Fusion Max — the product profile for complex reasoning and broader agentic work.

OpenCode requires named models in its provider configuration. The public gateway validates the transmitted ID; after acceptance, the Fusion core treats it as a compatibility label and the internal topology remains configuration-controlled.

Troubleshooting

Authentication error

Run opencode auth list and confirm that a credential exists for fumo. If necessary, repeat /connect and use the same provider ID as opencode.json.

Model not found

Confirm that the ID is listed under provider.fumo.models in opencode.json and authorized for your key. A client or public gateway may reject the model before the request reaches the Fusion core.

404 from the API

Set options.baseURL to https://capi.fumolab.ai/api/fusion/v1. OpenCode appends /chat/completions.

Tools do not work

Confirm that the provider uses @ai-sdk/openai-compatible. If the client adds provider-specific request fields, compare the request with the Fusion Chat Completions contract.

Resources

Configure OpenClaw

Supported models: fusion-max-2.0, fusion-max-1.0, fusion-code-1.0. Only Max 2.0 supports low / medium / high / max effort (default medium); the other two models do not support adjustment.