Models & Providers

yoyo supports 13 providers out of the box — from Anthropic and OpenAI to local models via Ollama.

Default model

The default model is claude-opus-4-6 (Anthropic). You can change it at startup or mid-session.

Changing the model

At startup:

yoyo --model claude-sonnet-4-20250514
yoyo --model gpt-4o --provider openai
yoyo --model llama3.2 --provider ollama

During a session:

/model claude-sonnet-4-20250514

Note: Switching models with /model preserves your conversation history — you can change models mid-task without losing context.

Providers

Use --provider <name> to select a provider. Each provider has a default model and an environment variable for its API key.

Tip: If you run yoyo without any API key configured, an interactive setup wizard will walk you through choosing a provider and entering your key. You can also save the config to .yoyo.toml directly from the wizard.

Provider	Default Model	API Key Env Var
`anthropic` (default)	`claude-opus-4-6`	`ANTHROPIC_API_KEY`
`openai`	`gpt-4o`	`OPENAI_API_KEY`
`google`	`gemini-2.0-flash`	`GOOGLE_API_KEY`
`openrouter`	`anthropic/claude-sonnet-4-20250514`	`OPENROUTER_API_KEY`
`ollama`	`llama3.2`	(none — local)
`xai`	`grok-3`	`XAI_API_KEY`
`groq`	`llama-3.3-70b-versatile`	`GROQ_API_KEY`
`deepseek`	`deepseek-chat`	`DEEPSEEK_API_KEY`
`mistral`	`mistral-large-latest`	`MISTRAL_API_KEY`
`cerebras`	`llama-3.3-70b`	`CEREBRAS_API_KEY`
`zai`	`glm-4-plus`	`ZAI_API_KEY`
`minimax`	`MiniMax-M2.7`	`MINIMAX_API_KEY`
`custom`	`claude-opus-4-6`	(none — bring your own)

Examples

# OpenAI
OPENAI_API_KEY=sk-... yoyo --provider openai

# Google Gemini
GOOGLE_API_KEY=... yoyo --provider google --model gemini-2.5-pro

# Local with Ollama (no API key needed)
yoyo --provider ollama --model llama3.2

# Custom endpoint (OpenAI-compatible API)
yoyo --provider custom --base-url http://localhost:8080/v1 --model my-model

You can also set these in .yoyo.toml:

provider = "openai"
model = "gpt-4o"
base_url = "https://api.openai.com/v1"

Cost estimation

Cost estimation is built in for many providers:

Model Family	Input (per MTok)	Output (per MTok)
Opus 4.5/4.6	$5.00	$25.00
Opus 4/4.1	$15.00	$75.00
Sonnet	$3.00	$15.00
Haiku 4.5	$1.00	$5.00
Haiku 3.5	$0.80	$4.00

Cost estimates are also available for OpenAI, Google, DeepSeek, Mistral, xAI, Groq, ZAI and more.

Context window

yoyo assumes a 200,000-token context window (the standard for Claude models). When usage exceeds 80% of this, auto-compaction kicks in. See Context Management.