add-model

name	add-model
description	Add or remove LLM model definitions for providers (Anthropic, OpenAI, Gemini, VertexAI, Bedrock). Use when the user provides a model card URL, documentation link, or plain text description of a new model to register. Also use when asked to remove/deprecate an existing model. Handles model struct definition, provider registration, README update, and schema regeneration.
user-invocable	true

Add/Remove Model Skill

Overview

Add a new model definition to the opencode project, or remove a deprecated one. Models live in internal/llm/models/ with one file per provider.

Model Struct Fields

Every model must populate these fields in Model{}:

Model{
    ID:                       ModelID,       // e.g. "claude-4.5-sonnet[1m]"
    Name:                     string,        // Human-readable, e.g. "Claude 4.5 Sonnet [1M]"
    Provider:                 ModelProvider, // e.g. ProviderAnthropic
    APIModel:                 string,        // API model identifier sent to provider
    CostPer1MIn:              float64,       // Cost per 1M input tokens (USD)
    CostPer1MOut:             float64,       // Cost per 1M output tokens (USD)
    CostPer1MInCached:        float64,       // Cost per 1M cached input tokens
    CostPer1MOutCached:       float64,       // Cost per 1M cached output tokens
    ContextWindow:            int64,         // Max context window size in tokens
    DefaultMaxTokens:         int64,         // Default max output tokens (0 if unset)
    CanReason:                bool,          // Whether model supports reasoning/thinking
    SupportsAdaptiveThinking: bool,          // Whether model supports adaptive thinking (reasoningEffort)
    SupportsMaximumThinking:  bool,          // Whether model supports "max" reasoning effort
    SupportsXHighThinking:    bool,          // Whether model supports "xhigh" reasoning effort (Opus 4.7+)
    SupportsTaskBudget:       bool,          // Whether model supports task_budget (beta, Opus 4.7+)
    SupportsAttachments:      bool,          // Whether model supports file attachments
}

Required Information from Model Card

Extract these from the model card/documentation. If any are missing, ask the user specifically:

1. API model name (the string sent in API calls)
2. Pricing: input cost, output cost, cached input cost, cached output cost (per 1M tokens)
3. Context window size (in tokens)
4. Max output tokens (default)
5. Reasoning support: does it support thinking/reasoning? Adaptive thinking? Maximum thinking? XHigh thinking?
6. Task budget support: does it support the task_budget beta feature? (requires task-budgets-2026-03-13 beta header)
7. Attachments: does it support file/image attachments?

For VertexAI models: the API model name format differs (e.g. claude-sonnet-4-5@20250929 instead of claude-sonnet-4-5). The model card usually provides this.

Adding a Model — Step by Step

1. Determine the provider file

Provider	File	Map variable	Provider const
Anthropic	anthropic.go	AnthropicModels	ProviderAnthropic
OpenAI	openai.go	OpenAIModels	ProviderOpenAI
Gemini	gemini.go	GeminiModels	ProviderGemini
VertexAI (Gemini)	vertexai.go	VertexAIGeminiModels	ProviderVertexAI
VertexAI (Anthropic)	vertexai.go	VertexAIAnthropicModels	ProviderVertexAI
Bedrock	bedrock.go	BedrockAnthropicModels	ProviderBedrock

2. Add the ModelID constant

Add a new ModelID constant in the provider file's const block. Follow naming conventions:

• Anthropic: Claude{Version}{Variant} e.g. Claude45Sonnet1M
• OpenAI: model name e.g. GPT5, O4Mini
• Gemini: Gemini{Version}{Variant} e.g. Gemini30Pro
• VertexAI: prefix with VertexAI e.g. VertexAISonnet45M
• The string value uses the provider prefix: "vertexai.claude-sonnet-4-5-m", "claude-4-5-sonnet[1m]", "gemini-3.0-pro"

3. Add the model definition to the map

Add entry to the appropriate map variable. For VertexAI models that mirror Anthropic/Gemini models, reference the base model's costs:

VertexAINewModel: {
    ID:               VertexAINewModel,
    Name:             "VertexAI: Model Name",
    Provider:         ProviderVertexAI,
    APIModel:         "model-api-name@version",
    CostPer1MIn:      AnthropicModels[BaseModelID].CostPer1MIn,
    // ... reference base model for shared fields
},

4. Verify bootstrap registration

Check bootstrap.go — the init() function must copy the model's map into SupportedModels. Existing maps are already registered. Only add a new maps.Copy() line if you created a new map variable.

5. Update README.md

Update the "Supported Models" table at line ~287 in README.md. Add the new model name to the appropriate provider row.

6. Regenerate schema

Run: go run cmd/schema/main.go > opencode-schema.json

This picks up new model IDs automatically via models.SupportedModels iteration.

7. Build check

Run: go build ./... to verify compilation.

Removing a Model

Reverse the add steps:

1. Remove the ModelID constant from the provider file
2. Remove the model entry from the map
3. Remove any VertexAI/Bedrock mirrors that reference the removed model
4. Update README.md to remove the model name
5. Regenerate schema: go run cmd/schema/main.go > opencode-schema.json
6. Build check: go build ./...

Output

After completing, provide a brief summary:

• Model name and ID
• Provider
• Key specs (context window, pricing tier, reasoning support)
• Whether it was added or removed