Sakana (Fugu)

Sakana AI serves its Fugu model family over an OpenAI-compatible API. Ptah converts between the Anthropic Messages protocol and OpenAI Chat Completions with a local translation proxy, so Fugu behaves like any other provider in the model picker.

What you need

An API key from console.sakana.ai/api-keys.

Setup

Open Settings → Providers → Sakana (Fugu).
Paste your API key.
Click Test connection.

Or from the CLI:

ptah provider set-key --provider sakana --key <your-key>
ptah provider default set sakana

The key is stored in the operating system’s secure credential store.

Models

Model	Role	Context
Fugu	Default routing model.	200K
Fugu Ultra	Highest-capability model.	200K

Both support tool use.

Ptah also fetches the live catalog from Sakana’s /v1/models endpoint, so dated aliases such as fugu-ultra-20260615 appear in the picker as Sakana publishes them. The two models above are the offline fallback and the source of the tool-use metadata that the OpenAI-style /v1/models response omits.

Model tiers

Sakana ships a verified tier map:

Tier	Model
`opus`	`fugu-ultra`
`sonnet`	`fugu`
`haiku`	`fugu`

Fugu ids do not name a tier, so this explicit map is what makes “Default (recommended)” resolve correctly. You can override any slot from the model picker, or from the CLI:

ptah provider tier set --tier opus --model fugu-ultra

Cost

Sakana does not publish pricing, so Ptah ships no cost data for Fugu models. The cost bar reports zero rather than guessing. Check your Sakana console for actual spend.

Troubleshooting

“Unauthorized” — the key is wrong or revoked. Regenerate it in the Sakana console and re-paste it.

Tool calls behave oddly — Sakana runs behind a translation proxy, so tool calls cross a protocol boundary. If a tool result looks malformed, report it with the execution tree attached.

The cost bar reads $0 — that is expected. Sakana’s pricing is unpublished, so Ptah records no rates for it.