Set Up ASI:One in OpenCode

Overview

ASI:One is OpenAI-compatible, so OpenCode can use it as a custom provider through the OpenAI-compatible runtime package. You declare the provider, its endpoint, and its models in opencode.json, then store your API key with OpenCode’s credential commands.

Custom providers like ASI:One are not loaded from ASI:One’s GET /v1/models. OpenCode reads the model list and context limits from your config. Built-in providers on Models.dev can pull metadata from that catalog; your asi block is the source of truth for ASI:One.

Prerequisites

• OpenCode v2 installed and on your PATH.
• An ASI:One API key. Create one at asi1.ai/developer. Keys start with sk_.
• An ASI:One plan that includes asi1-ultra. The same key also works for asi1 and asi1-mini.

Add the provider

Create or edit opencode.json or opencode.jsonc at the root of your project. OpenCode v2 expects a providers object. Each provider needs settings.baseURL. Without it, sessions fail with an error about the route missing an endpoint.

{
  "$schema": "https://opencode.ai/config.json",
  "model": "asi/asi1-ultra",
  "providers": {
    "asi": {
      "name": "ASI:One",
      "package": "aisdk:@ai-sdk/openai-compatible",
      "settings": {
        "baseURL": "https://api.asi1.ai/v1"
      },
      "models": {
        "asi1": {
          "name": "ASI1",
          "limit": { "context": 300000, "output": 40000 },
          "capabilities": {
            "tools": true,
            "input": ["text", "image"],
            "output": ["text"]
          }
        },
        "asi1-ultra": {
          "name": "ASI1 Ultra",
          "limit": { "context": 800000, "output": 40000 },
          "capabilities": {
            "tools": true,
            "input": ["text", "image"],
            "output": ["text"]
          }
        },
        "asi1-mini": {
          "name": "ASI1 Mini",
          "limit": { "context": 160000, "output": 40000 },
          "capabilities": {
            "tools": true,
            "input": ["text", "image"],
            "output": ["text"]
          }
        }
      }
    }
  }
}

To make ASI:One available in every project, put the same providers.asi block in ~/.config/opencode/opencode.json instead.

Older configs that used provider, npm, and options still load on OpenCode v2 through migration. New setups should use providers, package, and settings as above.

OpenCode uses each model’s limit to decide when to compact the conversation. context is the working window ASI:One publishes for tools like OpenCode (not the raw API maximum). output is how much room OpenCode reserves for the assistant reply. Both fields are required whenever a model has a limit block. If you omit limit, OpenCode falls back to generic defaults that are too small for asi1-ultra, so always set the limits above. The sample uses 40,000 for output as a safe default; raise it if replies feel cut off before compaction should kick in.

Optional: reasoning depth

asi1 and asi1-ultra support configurable reasoning depth. To expose effort levels in OpenCode, replace the existing asi1-ultra entry under providers.asi.models with the object below (same fields work on asi1; not needed for a first successful run):

{
  "asi1-ultra": {
    "name": "ASI1 Ultra",
    "compatibility": { "reasoningField": "reasoning" },
    "settings": { "reasoningEffort": "high" },
    "variants": [
      { "id": "low", "settings": { "reasoningEffort": "low" } },
      { "id": "medium", "settings": { "reasoningEffort": "medium" } },
      { "id": "high", "settings": { "reasoningEffort": "high" } }
    ],
    "limit": { "context": 800000, "output": 40000 },
    "capabilities": {
      "tools": true,
      "input": ["text", "image"],
      "output": ["text"],
      "reasoning": { "supported": true, "effort": ["low", "medium", "high"] }
    }
  }
}

Pick a variant when you start a session, for example opencode -m asi/asi1-ultra#high.

Store the API key

Add the provider block to your config file (opencode.json or opencode.jsonc) first so OpenCode knows about the asi integration. Then connect your key:

opencode auth login asi --method key

OpenCode prompts for the key without echoing it. The key is stored in OpenCode’s local credential store, not in your project.

To see saved integrations:

opencode auth list

Verify

List models that come from your config (look for the asi/ prefix):

opencode models | grep '^asi/'

You should see:

asi/asi1
asi/asi1-mini
asi/asi1-ultra

To confirm OpenCode merged the provider block and endpoint:

opencode debug config

Then send a request to each model you plan to use:

opencode run -m asi/asi1-mini "Reply with exactly: OK"
opencode run -m asi/asi1-ultra "Reply with exactly: OK"

Each should reply with OK.

Run it

Because the config sets "model": "asi/asi1-ultra", plain opencode starts on asi1-ultra. To pick a model for one session:

opencode -m asi/asi1-mini

Troubleshooting

Next steps

1. OpenWork: use the same models in OpenWork’s task UI
2. Codex: the same models in the Codex CLI
3. Cursor: the same models in the Cursor editor
4. Zed: the same models in the Zed editor
5. ASI:One Models: choosing between asi1, asi1-ultra and asi1-mini
6. Chat Completions API: the endpoint OpenCode talks to