> ## Content Index > Fetch the complete content index at: https://blog.arbitrum.foundation/llms.txt > Use this file to discover other available public pages before exploring further. # Builder's Block #007 - Solidity's Rebuild, Fusaka Upgrade & ERC-8004 - URL: https://blog.arbitrum.foundation/builders-block-007-soliditys-rebuild-fusaka-upgrade-erc-8004/ - Published: 2025-12-04T14:12:01.000Z - Updated: 2025-12-04T14:12:01.000Z - Author: Arbitrum Foundation - Tags: Builder Newsletter 💡 ****What's Important This Week** 🚂 Fusaka is now live. The wait is over! 🧬 Solidity's rebuild: Meet the new implementation ⚡ Real-time ZK proving is finally here ## 📣 Announcements *Key updates from the Arbitrum ecosystem and Foundation.* ### Fusaka: Ethereum's next major upgrade ![G63HAHtXgAEKGoP.jpeg](https://storage.ghost.io/c/d4/cc/d4cc8040-691e-4dd2-8282-0c08d45fc5a8/content/images/2025/12/G63HAHtXgAEKGoP.jpeg) Fusaka (Fulu + Osaka) combines PeerDAS scalability and native mobile security. Check the new upgrades: - **For Rollup Devs**: [PeerDAS](https://eips.ethereum.org/EIPS/eip-7594?ref=blog.arbitrum.foundation) & [Elastic Blobs](https://eips.ethereum.org/EIPS/eip-7892?ref=blog.arbitrum.foundation) decouple data capacity to slash fees (introduces "sampling") and dynamically scale throughput. - **For DeFi Devs**: [Based Preconfirmations](https://eips.ethereum.org/EIPS/eip-7917?ref=blog.arbitrum.foundation) & [Gas Caps](https://eips.ethereum.org/EIPS/eip-7825?ref=blog.arbitrum.foundation) enable sub-second "instant" UX and prevent single-tx block monopoly. - **For Wallet & Infra Devs**: [Native Passkeys](https://eips.ethereum.org/EIPS/eip-7951?ref=blog.arbitrum.foundation) via secp256r1 & [eth\_config](https://eips.ethereum.org/EIPS/eip-7910?ref=blog.arbitrum.foundation) unlock Secure Enclave signing and standardized node ops. - **For Protocol Devs**: [60M Gas Limit](https://eips.ethereum.org/EIPS/eip-7935?ref=blog.arbitrum.foundation) & [CLZ Opcode](https://eips.ethereum.org/EIPS/eip-7939?ref=blog.arbitrum.foundation) double L1 capacity and optimize heavy cryptographic operations. Also includes: [History expiry](https://eips.ethereum.org/EIPS/eip-7642?ref=blog.arbitrum.foundation) for lighter nodes, [MODEXP repricing](https://eips.ethereum.org/EIPS/eip-7883?ref=blog.arbitrum.foundation), and max block size [limits](https://eips.ethereum.org/EIPS/eip-7934?ref=blog.arbitrum.foundation). ➡️ [Fusaka Roadmap Here](https://ethereum.org/es/roadmap/fusaka/?ref=blog.arbitrum.foundation) --- ## 🛠️ Dev Tooling & Infra *Updates to SDKs, CLIs, and developer workflows across the stack.* ### Solidity faces a full rebuild The team behind Solidity maintenance has posted a new prototype called *Core Solidity*, which introduces a rebuild of the Solidity type system and compiler to improve compiler correctness, empower library authors, and expand the capabilities of analysis tooling. new language features Core Solidity takes ideas from pure functional and modern programming languages (e.g., Haskell, Lean, Rust, Zig). New features include: - Algebraic datatypes (also known as sum/ product types) and pattern matching - Generics/parametric polymorphism - Traits/type classes - Type inference - Higher-order and anonymous functions - Compile-time evaluation [Check the announcement ](https://www.soliditylang.org/blog/2025/11/14/core-solidity-deep-dive/?ref=blog.arbitrum.foundation) ### Scaffold Stylus has a new Chainlink integration The best template for starting your Stylus project now includes a new feature. Check out Chainlink Verifiable Randomness on Stylus. ➡️ [Try it with a single command](https://www.scaffoldstylus.com/?ref=blog.arbitrum.foundation) ### Nitro v.3.9.3 fixes Gas Target & Pricing Framework Nitro v.3.9.3, which introduces ArbOS 51, is optional on mainnet, but ArbSepolia node operators must upgrade before this activation to continue syncing the chain. ➡️ [Check the release](https://github.com/OffchainLabs/nitro/releases/tag/v3.9.3?ref=blog.arbitrum.foundation) --- ## 📚 Learn & Build *New learning drops and hands-on resources from across the Arbitrum ecosystem.* ### ERC-8004: The agentic economy is coming onchain AI on Arbitrum has a promising future. We recommend this 5-minute read about trust-minimized agent registries and how Stylus unlocks onchain validation for AI agents. ➡️ [Read the blog](https://blog.arbitrum.foundation/ai-on-arbitrum-establishing-an-agent-registry-with-erc-8004-2/) ### Ethereum Foundation presents OpenAC OpenAC is an anonymous credential design purposely constructed to be compatible with the European Digital Identity Architecture. ➡️ [Read the whitepaper](https://github.com/privacy-ethereum/zkID/blob/main/paper/zkID.pdf?ref=blog.arbitrum.foundation) ### Fortune Cookie Mini-App w/ Farcaster + Arbitrum Are you interested in minting your own fortune cookie? Be sure to check out our contributor's Farcaster mini-app, which is deployed on Arbitrum. Curious about how it's coded? Don't let learning be a mystery. ➡️ [Check out the code here](https://github.com/hummusonrails/holiday-fortune-cookie?ref=blog.arbitrum.foundation) --- ## 🔦 Ecosystem Highlights *Fresh launches and standout threads from around the Arbitrum ecosystem.* ### SP1 Hypercube proves 99.7% of Ethereum blocks in real time Succinct, an exclusive Arbitrum Partner, has unveiled a breakthrough in zero-knowledge tech, introducing real-time proving capabilities that promise to democratize proof generation and maintain liveness and a censorship-resistant network. ➡️ [Read the Thread on X](https://x.com/SuccinctLabs/status/1990764341264855356?ref=blog.arbitrum.foundation) ### Post-Quantum Resistant messaging with Session on Arbitrum ![v2v3.jpg](https://storage.ghost.io/c/d4/cc/d4cc8040-691e-4dd2-8282-0c08d45fc5a8/content/images/2025/12/v2v3.jpg) This move brings post-quantum cryptography to onchain communication, ensuring future-proof privacy for users. ➡️ [Read about Session Protocol](https://getsession.org/blog/session-protocol-v2?ref=blog.arbitrum.foundation) ### Reminder: $10M Audit Program Security is key. Applications are open for the Audit Program, an accelerator for your launch timeline that subsidizes security reviews and helps developers ship battle-tested contracts. ➡️ [Apply now](https://tally.so/r/3xzEzv?program=aap&ref=blog.arbitrum.foundation) ### Reminder: ArbiFuel Don't miss out on Arbifuel. This adoption accelerator provides gas sponsorship to help projects scale effectively, removing friction for users and improving the onboarding experience. ➡️ [Apply now](https://airtable.com/appzb4GfqGfrnDXjW/shrulGIIp6l6ezAlt?ref=blog.arbitrum.foundation) --- ## 🗓️ Events *Workshops, hackathons, and ecosystem meetups to watch.* ### ArbiVerse Highlights in Buenos Aires Missed the action? Catch up on the energy from ArbiPanadas, the insights from ArbiVerse, and all the key takeaways from DevConnect in this wrap-up of the week's events. ➡️ [Read the Thread on X](https://x.com/arbitrum/status/1994496466900193674?ref=blog.arbitrum.foundation) ### ArbiLink Brasil Recap is ready ![G6h_cH6aAAArnXd.jpeg](https://storage.ghost.io/c/d4/cc/d4cc8040-691e-4dd2-8282-0c08d45fc5a8/content/images/2025/12/G6h_cH6aAAArnXd.jpeg) The Arbitrum community in Brazil is heating up. Check out the recap from ArbiLink Brasil. ➡️ [Read the Forum post](https://x.com/arbitrum%5Fpt/status/1992982834601173351?ref=blog.arbitrum.foundation) --- ## 🧵 Forum & Community Discussions *What builders are debating and proposing this week.* ### Developers are encouraged to provide feedback on "The Long-term Solidity Roadmap" As you may have seen in the *What's Important This Week* or *Learn & Build* sections, Solidity is undergoing a significant redesign to give developers a better toolkit for the next generation of smart contracts. We invite developers to share their opinions and provide feedback on what they would like to see or what they already appreciate about Solidity. ➡️ [Read the Forum post](https://forum.soliditylang.org/t/call-for-feedback-the-long-term-solidity-roadmap/3530?ref=blog.arbitrum.foundation) --- That’s all from Builder’s Block #007\. Thank you for reading, and keep building. Arbitrum Everywhere.