Models — Eva docs

Set the model for one run with a flag, inside a session with the model command, or permanently with the model key. The Catalog holds what Eva knows.

A model reference is provider/model. Out of the box, Eva starts on anthropic/claude-opus-5.

Set the model for one run

eva --model anthropic/claude-sonnet-5

The flag works on every command, including --print.

Set it inside a session

/model anthropic/claude-sonnet-5

With no argument, /model shows the current model and offers the ones Eva knows about.

Set it permanently

The top-level model key in config:

~/.eva/config.yaml

model: anthropic/claude-sonnet-5

Configuration explains where that file goes and which layer wins when several set it.

What the catalog ships

Reference	Context window
`anthropic/claude-opus-5`	1,000,000
`anthropic/claude-sonnet-5`	1,000,000
`anthropic/claude-opus-4-8`	1,000,000
`anthropic/claude-haiku-4-5`	200,000
`openai/gpt-5.6`	1,050,000
`openai/gpt-5.4`	1,050,000
`openai/gpt-5.4-mini`	400,000
`openai/gpt-5.4-nano`	400,000
`openai/gpt-4o-mini`	128,000

A model behind a compatible endpoint joins this list when its entry names it, and runs either way when you type its reference.

The Catalog

The Catalog is the Domain holding providers, their models, and the default. Provider plugins write to it and nothing owns it, so adding a provider is adding a plugin rather than editing a list.

The Catalog also holds Price — what a vendor publishes per million tokens, vendored into the binary so boot needs no network. Price feeds an Estimate and never a Cost; cost and usage explains why those stay apart.

Credentials and retries

A model runs behind a provider, and the provider owns both. One API key in the environment connects each of the first-party providers, and retries are tunable per run. Providers has the whole of it.

More harnesses

The harnesses you already pay for — driven behind the same contract — arrive with the multi-harness stage. The roadmap says when.