add-opencode-model

name	add-opencode-model
description	REQUIRED when adding OpenCode Zen models - provides a script that fetches accurate context, max tokens, pricing, and capabilities from the API. Use this skill whenever the user asks to add, register, or configure a new OpenCode Zen model. Do NOT guess model specifications—always fetch real data from the API.

Add OpenCode Zen Model

Fetches model details from both OpenCode and OpenRouter APIs to provide structured information for the agent to add the model to source/models/opencode-zen-provider.ts.

Usage

Run this script from this file's directory.

./add-model.js google/gemini-3-flash-preview

How It Works

1. Confirms model exists in OpenCode API (https://opencode.ai/zen/v1/models)
2. Searches OpenRouter API (https://openrouter.ai/api/v1/models) for matching model to get:
   • Context window length
   • Max output tokens
   • Pricing information
   • Supported features (reasoning/tool calling)
3. Determines client type based on model provider:
   • openai → uses @ai-sdk/openai (Responses API)
   • google → uses @ai-sdk/google (custom base URL)
   • anthropic → uses @ai-sdk/anthropic
   • openai-compatible → uses createOpenAICompatible
4. Outputs JSON with all details needed to add the model

JSON Output Format

The script outputs a JSON object wrapped in markers:

--- MODEL_DETAILS_JSON_START ---
{...}
--- MODEL_DETAILS_JSON_END ---

JSON Structure

{
  "modelKey": "gemini-3-flash-preview",
  "opencodeId": "google/gemini-3-flash-preview",
  "openrouterId": "google/gemini-3-flash-preview",
  "providerFile": "./source/models/opencode-zen-provider.ts",
  "registryId": "opencode:gemini-3-flash-preview",
  "clientType": "google",
  "registryEntry": {
    "id": "opencode:gemini-3-flash-preview",
    "provider": "OpenCode",
    "contextWindow": 1048576,
    "maxOutputTokens": 65535,
    "defaultTemperature": 0.5,
    "promptFormat": "markdown",
    "supportsReasoning": 
     
     
     
  
   
     
     
     
     
  
   
     
     
     
     
     
     
     ...
     ...
  

Client Type Reference

Client Type	Library	Base URL	Example Models
openai	@ai-sdk/openai	Responses API	openai/gpt-4o
google	@ai-sdk/google	https://opencode.ai/zen/v1/models/<model-id>	google/gemini-3-flash-preview
anthropic	@ai-sdk/anthropic	Messages API	anthropic/claude-3-5-sonnet
openai-compatible	@ai-sdk/openai-compatible	https://opencode.ai/zen/v1	All other models

How to Add Model to Provider File

Step 1: Add client if needed

In source/models/opencode-zen-provider.ts, check if you need to add a new client based on clientType:

// For OpenAI models (Responses API)
import { createOpenAI } from "@ai-sdk/openai";
const openaiClient = createOpenAI({
  apiKey: process.env["OPENCODE_ZEN_API_TOKEN"] ?? "",
  baseURL: "https://opencode.ai/zen/v1",
});

// For Google models
import { createGoogle } from "@ai-sdk/google";
const googleClient = createGoogle({
  apiKey: process.env["OPENCODE_ZEN_API_TOKEN"] ?? "",
  baseURL: "https://opencode.ai/zen/v1/models/<model-id>",
});

Step 2: Add to opencodeZenModels object

Find the opencodeZenModels const object and add the new model entry in alphabetical order by key, using the appropriate client:

const opencodeZenModels = {
  "glm-4-7": completionsClient("glm-4.7-free"),
  "minimax-m2-1": messagesClient("minimax-m2.1-free"),
  // For OpenAI-compatible models:
  "new-model": completionsClient("provider/new-model"),
  // For Anthropic models:
  "claude-model": messagesClient("anthropic/claude-model"),
  // For Google models:
  "gemini-flash": googleClient("google/gemini-3-flash-preview"),
} as const;

Step 3: Add to opencodeZenModelRegistry object

Find the opencodeZenModelRegistry object and add the registry entry in alphabetical order by registryId:

export const opencodeZenModelRegistry: {
  [K in ModelName]: ModelMetadata<ModelName>;
} = {
  "opencode:glm-4-7": {
    id: "opencode:glm-4-7",
    provider: "opencode",
    // ... existing entry ...
  },
  // ... existing entries ...
  "opencode:new-model": {
    id: "opencode:new-model",
    provider: "opencode",
    contextWindow: 1048576,
    maxOutputTokens: 65535,
    defaultTemperature: 0.5,
    promptFormat: "markdown",
    supportsReasoning: true,
    supportsToolCalling: true,
    costPerInputToken: 0.0000005,
    costPerOutputToken: 0.000003,
  },
  // ...
};

Step 4: Validate changes

Run the project's validation commands:

npm run typecheck
npm run lint
npm run format

Field Mapping Reference

JSON Field	Registry Field	Notes
registryEntry.id	id	Full registry ID
registryEntry.provider	provider	Always "opencode"
registryEntry.contextWindow	contextWindow	From OpenRouter API
registryEntry.maxOutputTokens	maxOutputTokens	From OpenRouter API
registryEntry.defaultTemperature	defaultTemperature	Inferred from model ID
registryEntry.promptFormat	promptFormat	Inferred from model family
registryEntry.supportsReasoning	supportsReasoning	From OpenRouter API
registryEntry.supportsToolCalling	supportsToolCalling	From OpenRouter API
registryEntry.costPerInputToken	costPerInputToken	From OpenRouter API
registryEntry.costPerOutputToken	costPerOutputToken	From OpenRouter API

Matching Strategy

The script uses multiple strategies to find a matching OpenRouter model:

1. Direct key match: Match by model key (e.g., glm-4.7 matches glm-4.7)
2. Provider + name match: Match by provider prefix and model name (e.g., google/gemini-3-flash matches google/gemini-3-flash-preview)
3. Partial name match: Match by partial model name (fallback)

If no match is found, defaults are used for pricing and capability fields.

Default Value Inferences

Field	Logic
defaultTemperature	Returns -1 if model ID contains "codex", "coder", or "code"; otherwise 0.5
promptFormat	Maps model family to format: gemini/claude/qwen/mistral/moonshotai → "markdown", gpt/openai → "xml", deepseek → "bracket", defaults to "markdown"
maxOutputTokens	Falls back to context_length if not available from OpenRouter
costPerInputToken	Defaults to 0 if no OpenRouter match
costPerOutputToken	Defaults to 0 if no OpenRouter match

Error Handling

• Validates model ID exists in OpenCode API
• Shows first 10 available OpenCode models if ID not found
• Warns if no matching OpenRouter model found
• Provides clear error messages with suggestions

Examples

# Add Google Gemini Flash
./add-model.js google/gemini-3-flash-preview

# Add OpenAI GPT model
./add-model.js openai/gpt-4o

# Add Anthropic Claude model
./add-model.js anthropic/claude-3-5-sonnet

# Add other provider model
./add-model.js deepseek/deepseek-v3