# Anthropic Unveils FlashProve for Proving Which Model Answered You

*Author: William M. Peaster*
*Published: Nov 3, 2026*
*Source: https://www.bankless.com/read/news/anthropic-unveils-flashprove-for-proving-which-model-answered-you*

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Anthropic's Frontier Red Team released [FlashProve](https://www.anthropic.com/research/provable-inference), an Apache-licensed library that lets an AI provider cryptographically prove a response came from a specific set of model weights, without revealing the weights. It leans on the same family of hash-based proofs that power Ethereum L2s like Starknet. 

> [ — (@)
> ](https://twitter.com/gakonst/status/2117658488558272755)

# **What's the Scoop?**

- **The problem:** When you query an AI API, you can't tell whether the model you paid for actually answered, or whether a router quietly swapped in a cheaper one. FlashProve has the provider publish a fingerprint of its weights once, then attach a proof to each reply showing those exact weights produced it. 

- **The numbers:** On Llama 4 Maverick, a 400B-parameter model, the prover runs at about 110 tokens per second on a single H100. Proofs weigh in around 19 MB and a plain CPU can check one in roughly 17 to 21 seconds. 

- **The catch:** Proving still costs roughly 70 to 95x the GPU time of normal inference, a single request waits around five minutes for its batch, and context is capped at 1,024 tokens. Anthropic calls it a research prototype and says it isn't maintaining the [repo](https://github.com/anthropics/FlashProve). 

- **Crypto's fingerprints:** The report cites WHIR, STIR, and the broader STARK research lineage, and ships Lean-verified proofs alongside the code. StarkWare and Succinct, whose co-founders and fellows appear among the authors, were quick to claim a share of the win. 

- **Big picture:** An agent or oracle that can prove "model X said Y" is a missing piece for AI-driven DeFi and prediction market resolutions. At 19 MB and 17 seconds per check, that's not happening onchain without recursion that isn't part of this release. But a frontier lab publicly building on the same math as Ethereum's ZK rollups is a legitimacy transfer the STARK camp has waited years for.
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