Function, a Bitcoin-centric DeFi infrastructure entity, has unveiled the FBTC Agent software development kit. With this toolkit, which aims to turn Bitcoin into programmable capital, Function is transforming beyond cross-chain liquidity and packaged assets. As Function announced in its official press release, the initiative lets AI agents read positions, prepare transfers, and evaluate market context. As a result, the SDK creates the $BTC liquidity flows to various credit markets, while the user retains control over the final execution.
Bitcoin becomes programmable capital.
Introducing the FBTC Agent SDK feature: agent-native tools to bring FBTC to DeFi via Ethereum and @Mantle_Official.
Built for developers using Vercel AI SDK, custom agent loops, or Coinbase AgentKit.— Function 🌗 (@FunctionBTC) July 20, 2026
Function’s FBTC Agent SDK goes live to revolutionize Bitcoin’s role in DeFi
Function’s launch of the FBTC Agent SDK marks a major development toward redefining Bitcoin ($BTC) into an accessible and active means for agents to work within the DeFi networks. Additionally, the SDK provides agent-native tools that allow developers to seamlessly integrate with entities such as Vercel AI SDK, custom agent loops, and Coinbase AgentKit.
Additionally, it exposes FBTC metadata, transfer flows for $FBTC offerings, and credit market data on Aave V3 (Mantle and Ethereum). Builders can now develop workflows where AI agents reportedly query balances, prepare credit transfers, and inspect reserves, all while ensuring deterministic validation and execution. The respective approach addresses the increasing demand for exclusive and programmable BTCFi instruments that combine user-controlled security with automation.
At the same time, Function officially released a number of packages with specific execution boundaries. In particular, the package “@functionfbtc/sdk-agent” is reportedly framework-agnostic and focuses on conservative transfer preparation. Thus, it generates transfer parameters for consumer assessment. As a result, it ensures that agents never submit or sign transfers directly. On the other hand, the package “@functionfbtc/sdk-agentkit” extends Coinbase AgentKit with the registration of Aave V3 and FBTC actions. The version also performs authorizations and deliveries via configured wallets, returning transfer receipts for greater transparency.
Transforming Bitcoin into programmable capital
According to Function, the SDK supports Aave V3-based $FBTC lending positions in Mantle and Ethereum. Therefore, agents can seamlessly observe health factors, query balances, and manage withdrawal, delivery, repayment, and lending activities, including stablecoins such as $USDe, $USDT, and $USDC. Interestingly, the SDK implements network prompts, ensuring that the Mantle and Ethereum contexts remain recognizable. Overall, the rollout highlights a broader market trend where Bitcoin ($BTC) is more than digital gold and transforms into a programmable capital that can be integrated into the next generation DeFi stack.