Fugu Ultra for Contract Review

Fugu Ultra is a multi-agent orchestration system released by Sakana AI, a Tokyo-based AI company, on June 22, 2026. It does not run its own model weights; instead it routes each part of a task to frontier models such as Claude, GPT, and Gemini through one OpenAI-compatible API and returns a single combined answer. Its coordination approach is based on two ICLR 2026 papers, TRINITY and Conductor.

Fugu Ultra is the higher-performance tier of the Fugu family, aimed at harder tasks, while standard Fugu prioritizes lower latency and cost. It is available only as a hosted API; its weights are not open-source. Sakana lists pricing of $5 per million input tokens and $30 per million output tokens, with subscription tiers.

This page covers where Fugu Ultra can help with contract review - comparing clauses, spotting issues, and drafting redline suggestions - always subject to attorney review, and the important fact that reviewing a client contract sends its text to third-party models.

What Fugu Ultra can do in contract review

As a general assistant, Fugu Ultra can accelerate the mechanical parts of contract review that a lawyer would otherwise do line by line. It works from the text you supply and produces suggestions for a human to accept, reject, or refine.

The tasks below are ones where a capable general model can save time. Each output is a draft observation, not a legal conclusion, and must be checked against the actual contract, the deal terms, and applicable law.

• Compare two versions of a contract and list where they differ.
• Compare a clause against a standard or playbook clause you provide.
• Spot potentially missing or one-sided terms for a lawyer to review.
• Draft suggested redline language for a human to evaluate.
• Summarize a long agreement into a plain-language overview.

Confidentiality: client contracts leave to third-party models

Contract review is high-stakes for confidentiality because the document itself is the client's sensitive material, often containing party names, pricing, and negotiated positions. With Fugu Ultra, the contract text you submit is routed to third-party frontier vendors (Anthropic, OpenAI, or Google), so confidentiality and privilege depend on both Sakana's terms and every downstream vendor's terms.

Sakana has not stated that it offers a BAA or any specific certification for Fugu. Before pasting a client contract into the tool, confirm in writing how the document is stored, logged, and routed by every model in the chain, and whether any provider retains it or uses it for training.

Under ABA Model Rule 1.6, lawyers must make reasonable efforts to prevent unauthorized disclosure. Sending a full client contract through an unvetted multi-vendor pipeline can jeopardize that duty and, depending on the terms, may affect privilege. Consider whether the counterparty or an NDA restricts sending the document to third-party processors at all.

Accuracy limits in clause analysis

Fugu Ultra can be confidently wrong about contracts. It may misread a defined term, miss a cross-reference that changes a clause's meaning, invent a standard that does not apply, or overlook a material risk. It can also state a legal effect for a clause that is incorrect for the governing jurisdiction.

Because it fabricates plausibly, a suggestion can look authoritative while being wrong. Do not accept a flagged issue or a redline without confirming it against the full contract and the relevant law. The tool does not know your client's commercial priorities unless you tell it, and even then its judgment is not a substitute for a lawyer's.

If you ask it to cite law about a clause, the same fabrication risk applies as in legal research: verify any citation in a primary source.

• Confirm defined terms and cross-references before trusting a clause reading.
• Do not accept a redline without checking it against the whole contract.
• Verify any cited law separately - AI citations can be fabricated.

Human review and responsibility

Contract review output from Fugu Ultra is a draft that a qualified attorney must review, correct, and own. The lawyer remains responsible for the advice given to the client, regardless of how the first pass was produced.

Under ABA Model Rules 5.1 and 5.3, supervising lawyers are responsible for work produced with technology and non-lawyer assistance. A clear internal rule - that AI suggestions are never sent to a client or counterparty without attorney sign-off - keeps that responsibility intact.

Layer3 Labs is not a law firm and this page is not legal advice. It describes how the tool behaves so a firm can set its own review policy.

• A responsible attorney reviews and signs off on every AI suggestion.
• No AI-drafted redline goes to a client or counterparty unreviewed.
• The lawyer, not the tool, owns the advice.

Honest fit for contract review

Fugu Ultra is a reasonable fit for first-pass comparison and issue-spotting on lower-sensitivity contracts, or on de-identified or templated documents, where a lawyer reviews everything. It can genuinely save time on version diffs and clause-by-clause comparison.

It is a poor fit for reviewing sensitive client contracts before the multi-vendor routing and retention terms are confirmed in writing, or where an NDA prohibits third-party processing. It is also a poor fit when a firm requires a signed BAA or specific certification that Sakana has not stated for Fugu. For high-volume, low-complexity comparison, the lower-cost standard Fugu tier may be more economical than Ultra's $30-per-million output-token pricing.

• Good fit: de-identified or lower-sensitivity comparison and issue-spotting with review.
• Poor fit: sensitive client contracts before written routing/retention confirmation.
• Poor fit: documents an NDA bars from third-party processing.
• Poor fit: firms needing a BAA or certification Sakana has not stated.