The Fugu app is a browser, a console, or a CLI

1. A store search will not find a stated Fugu app

People who type "fugu app" are usually looking for something they can install. On 10 October 2026 the official Sakana Chat FAQ, the Fugu product page, the Get Started page, and the pricing page do not name an Apple App Store or Google Play listing, an iOS build, or an Android build. A dedicated phone app is not stated.

What those pages do name is a website, a developer console, and two command-line launchers. SakanaFugu.com is an independent guide. It is not the Fugu app, it is not operated by Sakana AI, and it cannot sign you in.

Treat any third-party "Fugu APK", browser extension, or unofficial wrapper as outside this check. This page does not review them, because none of the first-party pages above list one.

2. Sakana Chat is the consumer app

Sakana Chat lives at chat.sakana.ai. Sakana AI's 17 September 2026 post describes it as the place to try Sakana models without going through an API. The same post says Chat launched in March 2026 with Sakana Namazu, that an August update added Sakana Fugu plus code execution and image and document attachments, and that the Fugu option in Chat now runs on Fugu Max.

The Chat FAQ, read the same day, still defines the product as Namazu with web search and Japanese answers. Both pages are official, and they do not say the same sentence. Use the FAQ for account, price, region, and data rules. Use the 17 September post for the model picker. The post says no extra setup is required: select Fugu Max in the model picker. It does not publish an API model ID such as fugu-max-v1.0 for that picker, so this site will not claim the Chat button and the API ID are the same build.

Price, on the FAQ: Sakana Chat is currently free, and a future price change would be announced in advance. You can send messages without registering an email. Registration saves conversation history and raises the usage cap. A numeric cap is not stated. The FAQ says a request limit exists so the service stays stable, and that logged-in ordinary use rarely hits it. How many messages that is, is not stated.

The 17 September post also adds memory. What you tell Chat once, such as your role or how you want answers written, can carry into later conversations for both Namazu and Fugu Max. You can review or turn memory off in settings. Memory starts with conversations after that update; earlier conversations are not included. The post does not say memory is a paid feature.

Phone use is a browser, not an install. The FAQ recommends the latest Google Chrome and says PC and smartphone are supported. Data rules on that FAQ: conversation history and account information are stored on Google Cloud infrastructure in Japan; inputs may be used to improve models unless you opt out under Privacy in settings; personal information of yourself or others must not be entered. A chat window inside the API console is not what this FAQ describes.

Billing depth for a chat you build yourself is a different page. The Sakana Fugu chat guide prices an API conversation. This page only decides which app you open.

3. The console is the developer app, not the chat app

The Get Started page at console.sakana.ai says Sakana AI offers Fugu and Sakana Namazu through one API key, on OpenAI-compatible endpoints, with every endpoint under https://api.sakana.ai. You create the key in the console. The key is shown once. Store it before you close the dialog. Namazu is not included in subscription plans and is billed pay-as-you-go. Fugu and Namazu share the key.

The console's documented jobs are the key, billing mode, and, for the default fugu model, which providers stay in the pool. Get Started says the fugu model routes across supported providers by default. To opt a provider out, turn on the custom model pool while creating or editing the key and leave only the providers you want. Leave that setting off to keep the full default pool. The product FAQ says the same opt-out lives in the console settings menu, and that it applies to Fugu. Ultra and Max keep a fixed pool. A transcript view, a model picker that looks like Chat, or a mobile console app is not stated on these pages.

Pricing, rechecked on the console pricing page on 10 October 2026, is an API fact. Pay-as-you-go tokens are served at higher priority than monthly-plan tokens. Subscriptions are Standard at $20 a month, Pro at $100 (ten times Standard usage), and Max at $200 (twenty times Standard usage). Every tier includes Fugu, Fugu Ultra, and Fugu Max. The Standard allowance in tokens is not published. Fugu Ultra v2.0 is $5 input, $0.50 cached input, and $30 output per million tokens up to 272K request context, and $10, $1.00, and $45 above that, with orchestration tokens billed on top. Fugu Max v1.0 is a flat $2, $0.25, and $6 at any context length, and web_search or web_fetch is $0.007 per call. Fugu Cyber rates are not published; the page points readers to sales. The pricing guide and the calculator apply those published rates. They do not price Chat, because Chat has no token table.

One sentence on the pricing page matters more than the rate table if you came here from an app search: these subscriptions are for the Sakana AI API platform only. Sakana Chat has no subscription plan, and subscribing does not remove or change Sakana Chat usage limits. Paying $20 does not turn Chat into Ultra, and it does not raise the Chat cap. The subscription versus pay-as-you-go page covers that split.

4. Codex and Claude Code are the coding apps

The closest thing to an installable Fugu app, on the Get Started page, is a launcher for tools you already run in a terminal. Sakana documents one command:

curl -fsSL https://sakana.ai/fugu/install | bash

After that, the same page says to launch Codex with codex-fugu or Claude Code with claude-fugu. The one-line install supports Ubuntu and macOS. On Windows, or if the install does not finish, the page says to set the files up by hand. The claude-fugu launcher does not auto-update. To pick up newer Fugu models for Claude Code, the page says to recheck Get Started and apply the update yourself. Compatibility differences with Claude Code are described as mostly cosmetic, because Claude Code is closed source. This site has not run the installer, so the commands above are quoted from that page, not from a local test.

The product page's own "how do I get started" answer is the same idea without a brand name: point an existing client or coding harness at the Fugu endpoint with your API key. No SDK migration is required. New work should use the Responses API. The API quickstart shows the model IDs and the usage fields to store. Timeouts need to be longer for Ultra and Cyber; the Get Started note says so, and it does not publish a required millisecond value beyond the Codex stream settings in its manual setup.

Those launchers are still the paid API. They are not Sakana Chat. A coding session spends the key's subscription or pay-as-you-go balance. Which model the launcher lists is a catalog on the Get Started page, including Fugu, Fugu Ultra v2.0, and Fugu Max. Pin a version when a comparison has to stay still. See when to pin a model ID.

5. Which Fugu surface to open

Pick Chat when you want a conversation and you are in Japan. Pick the console when the Fugu app is software you are writing. Pick the launcher when the Fugu app is the coding tool already on your machine. If you need a model you can opt providers out of, that control is documented for default fugu only. Ultra and Max stay on a fixed pool, which the model chooser treats as a product constraint, not a setting you missed.

Partner websites are a fourth door, not a fifth app. The product page lists other platforms. A listing is not a copy of Chat's free tier or of the console's training opt-out. What this site can and cannot verify is on the third-party access page.

6. How to start, using only the official steps

Open the browser app

1. Go to chat.sakana.ai. The FAQ says this works from Japan, in the latest Google Chrome, on a PC or a smartphone.
2. Send a message without an account if you only need a one-off answer. Register if you want history and the higher cap. The size of either cap is not stated.
3. If the model picker shows Fugu Max, the 17 September 2026 post says that is the current Fugu option and that no extra setup is required. If the picker does not show it, that absence is not stated as an error code anywhere on the pages checked today.
4. Memory and training opt-out are settings, not install steps. Review both before you paste a work document. The FAQ forbids entering personal information.

Open the developer console

1. Create an API key in the console. Copy it before the dialog closes. It is shown once.
2. Choose a billing mode. Subscriptions start at $20 a month and include Fugu, Ultra, and Max. Pay-as-you-go is the higher-priority path and the only published path for Cyber, after a reviewed request. See Cyber access before you treat Cyber as a hidden app.
3. For default fugu, decide whether the custom model pool stays off. Turning it on and clearing providers changes the single rate you pay, because Fugu bills the top-tier model left in the pool and does not stack fees. Ultra and Max do not offer that opt-out.
4. Send a first request to https://api.sakana.ai/v1 with the Responses API for new work. Log orchestration fields on Ultra or the invoice will look smaller than the charge.

Open Fugu inside a coding tool

1. On Ubuntu or macOS, run the installer command published on Get Started. On Windows, follow that page's manual setup. This site does not republish a second installer.
2. Start codex-fugu or claude-fugu. Keep the API key out of the shell history you share.
3. If Claude Code stays on an old Fugu model, that matches the documented behavior: claude-fugu does not auto-update. Recheck Get Started and apply the update it describes.

7. Region rules decide whether the app opens

The two products do not share a region rule. Sakana Chat's FAQ says Chat is available only from inside Japan. The Fugu product FAQ says the API is available from outside Japan, and that Sakana does not provide the service to users in EU or EEA member states. The product page banner says Fugu is not yet available in the EU or EEA while Sakana works toward GDPR and EU-specific rules. Other regions may also fail because of network conditions or local regulations. That last clause does not name the countries.

If a production user is in the EU or EEA, do not plan the architecture on Fugu, and do not read a failure as a slow network. This site does not describe a VPN, a proxy, or a billing-address workaround. The EU and EEA page records that stop. A phone in Japan can open Chat. A laptop in the EU should not be pointed at the API and then "fixed" with a tunnel.

Training use is also per product. Chat's FAQ says you can opt out in the Privacy section of settings, and that opting out keeps the basic Chat features. The Fugu product FAQ says API customers can opt out of training use from the console. Neither page says one opt-out covers the other product.

8. A practical pick

Frequently asked questions

Sources and verification boundary

• Sakana Chat FAQ: free status, optional account, Chrome, PC and smartphone, Japan-only access, unpublished rate limit, Japan Google Cloud storage, training opt-out (checked October 10, 2026)
• Sakana AI, Sakana Chat update: Fugu Max in the Chat picker, memory, March 2026 launch, August attachments and code execution (posted September 17, 2026; page fetched October 10, 2026)
• Sakana AI Get Started: API host, one-time key, Ubuntu and macOS installer, codex-fugu, claude-fugu, Windows manual setup, no auto-update for claude-fugu (checked October 10, 2026)
• Sakana AI Pricing: API-only subscriptions, Chat limits unchanged by a subscription, Ultra and Max rates, Cyber unpublished (checked October 10, 2026)
• Sakana AI Fugu product page: EU and EEA restriction, get-started answer, fixed Ultra and Max pools, console opt-out for Fugu (checked October 10, 2026)

SakanaFugu.com is an independent guide and is not affiliated with Sakana AI. A store app, a numeric Chat cap, and the API model ID behind Chat's Fugu Max button are not stated on the pages above. Recheck those pages before you rely on a price or a region rule.