Opencode Desktop configuration

Step-by-step instructions to configure OpenCode Desktop on to use the ElettraGateway LLM gateway (https://llm-api-gw.elettra.eu/v1) and its models.

All steps below are for your Windows user account. <you> means your existing user name used to log-in to your machine, e.g. C:\Users\name.surname\...on Windows or /home/name.surname on Linux.

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Step 1 — Create the configuration file opencode.jsonc

OpenCode reads its global configuration from:from the file:

C:\Users\<you>\.config\opencode\opencode.jsonc

Create the .config\opencode folder and the opencode.jsonc file if they do not exist yet:

Paste the following content into opencode.jsonc and save it:

{
  "$schema": "https://opencode.ai/config.json",
  "provider": {
    "elettragateway": {
      "name": "ElettraGateway",
      "npm": "@ai-sdk/openai-compatible",
      "options": {
        "baseURL": "https://llm-api-gw.elettra.eu/v1"
      },
      "models": {
        "balanced": {
          "name": "balanced",
          "limit": {
            "context": 262144,
            "input": 262144,
            "output": 100000
          },
          "modalities": {
            "input": ["text", "image"]
          }
        },
        "top": {
          "name": "top",
          "limit": {
            "context": 1000000,
            "input": 1000000,
            "output": 100000
          },
          "modalities": {
            "input": ["text", "image"]
          }
        },
        "fast": {
          "name": "fast",
          "limit": {
            "context": 131000,
            "input": 131000,
            "output": 100000
          }
        }
      }
    }
  }
}

What this does

• Registers a custom, OpenAI-compatible provider named ElettraGateway pointing at the gateway URL.
• Declares the available models and their context limits (limit.context, limit.input, limit.output) — this is what OpenCode uses for context accounting.
• modalities.input: ["text", "image"] marks the models that accept images.

Tip: No API-KEY is stored in this file.

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Step 2 — Start (or reload) OpenCode Desktop

Launch OpenCode Desktop.

If the app was already running while you edited opencode.jsonc, please restart it.

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Step 3 — Enable the models

The desktop app keeps its own list of which models appear in the model picker. Models that are not enabled there are hidden, even when they are correctly configured.

1. Click on the "three rows icon" (see screenshot), select File -> Settings.
2. Go to Providers — "Chooseverify whichthat modelsElettraGateway appear in model picker".appears.
3. Go to Models, — "Choose which models appear in model picker".

Switch off everything not belonging to ElettraGateway,ElettraGateway and switch on the ElettraGateway models (top, balanced, `fast), or use Enable all models.

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Step 4 — Set the api key

1. Go back to the main Opencode Desktop window clicking on the "back to app" on the top left corner.
2. Type /connect as in the screenshot below, select it and click enter.
3. Type ElettraGateway as in the screenshot below, select the gateway from the services by cliking on it.
4. Paste the provided apikey in the appearing dialog window and press continue.

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Step 5 — Testing

1. You should be on the main Opencode Desktop window.
2. The main screen presents 3 elements (refer to the screenshot below):

• a: the selection box, allowing to switch between the build/plan phase; start in plan mode to analyse and plan the work, switch to build to actually edit existing files, perform actions, etc.
• b: when clicked, the model selection box allow you choose between the configured modelsmodels. Top should already be the default.
• c: Opencode utiliseutilises "workspaces" to organise the work. A workspace is an existing folder in the filesystem. Opencode will edit, write new files within that folder and will not asks for permissions.

Pick

Set the project workspace fodler, pick one of the ElettraGateway models, e.g. top or balanced.

Send a test prompt "hello" and check that a reply arrives.

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Troubleshooting

Symptom Cause / fix Only some models appear in the picker Step 4: the model is disabled in Settings → Models (models not listed there are hidden by default). No ElettraGateway provider at all opencode.jsonc not found or not valid JSON/JSONC. Check the path from Step 1 and validate the syntax (a missing } or a trailing comma breaks the whole file). 401 / "API key required" errors The key is missing or wrong — re-check auth.json (Step 2) or the apiKey field. Changes to opencode.jsonc seem ignored Use /reload in the app, or restart it. Config is merged from the global file plus any opencode.json(c) in the project folder. Still stuck Inspect the logs: C:\Users\<you>\.local\share\opencode\log\opencode.log (background service) and C:\Users\<you>\AppData\Roaming\ai.opencode.desktop\logs\ (app). Look for configuration normalization diagnostic warnings — they point to malformed config.

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Appendix — where things live

What Path Global configuration (providers, models) C:\Users\<you>\.config\opencode\opencode.jsonc CLI/TUI settings (not used by the desktop) C:\Users\<you>\.config\opencode\cli.json API keys / credentials C:\Users\<you>\.local\share\opencode\auth.json Sessions database C:\Users\<you>\.local\share\opencode\opencode.db Service log C:\Users\<you>\.local\share\opencode\log\opencode.log Desktop app GUI settings (model visibility, layout, tabs) C:\Users\<you>\AppData\Roaming\ai.opencode.desktop\drafts.sqlite Desktop app logs C:\Users\<you>\AppData\Roaming\ai.opencode.desktop\logs\

Appendix — useful keyboard shortcuts

Action Shortcut Open settings Ctrl+, Choose model Ctrl+' New session Ctrl+T / Ctrl+N Open project Ctrl+O Toggle terminal `Ctrl+`` Command palette search everything (Settings → Search everything)