# Developers - [Tech Hub](https://docs.fira.money/developers/developers.md) - [Protocol Primer](https://docs.fira.money/developers/fira-protocol-primer.md): A high-level introduction to the Fira protocol — what it does, why it exists, and how the pieces fit together. - [Features](https://docs.fira.money/developers/features.md): The Fira protocol provides a comprehensive set of features for yield tokenization, fixed-rate lending, and liquidity provisioning on Ethereum. - [Fixed-Rate Lending](https://docs.fira.money/developers/features/fixed-rate-lending.md): Fira enables fixed-rate borrowing through a lending market where BT serves as the loan token, giving borrowers predictable costs. - [Variable-Rate Lending](https://docs.fira.money/developers/features/variable-rate-lending.md): Fira supports variable-rate lending and borrowing through the SisuVault and a standard lending market with oracle-enforced LTV. - [Bond Token (BT)](https://docs.fira.money/developers/features/bond-token-bt.md): Bond Token (BT) is the fixed-rate principal token in Fira's yield tokenization system. - [Coupon Token (CT)](https://docs.fira.money/developers/features/coupon-token-ct.md): Coupon Token (CT) is the floating-yield token in Fira's yield tokenization system, representing a claim on variable yield generated by the underlying asset. - [FW (FiraWrapped)](https://docs.fira.money/developers/features/fw-fira-wrapped.md): FW (Fira Wrapped) tokens are ERC-20 wrappers around yield-bearing assets that provide the base layer for the entire Fira protocol. - [Fira Market AMM](https://docs.fira.money/developers/features/fira-market-amm.md): The Fira Market is a specialized AMM for trading Bond Tokens against Fira Wrapped tokens, with time-decaying implied-rate pricing. - [Rehypothecation](https://docs.fira.money/developers/features/rehypothecation.md): The Rehypothecation Module controls how FW tokens balance between idle reserves and yield-generating vault deployments. - [Liquidity Injector](https://docs.fira.money/developers/features/liquidity-injector.md): The Liquidity Injector bootstraps fixed-rate lending markets by minting and supplying BT as initial liquidity. - [Architecture](https://docs.fira.money/developers/architecture.md): An overview of Fira's system architecture, module dependencies, and cross-cutting design decisions. - [Router Architecture](https://docs.fira.money/developers/architecture/router-architecture.md): The Fira Router uses a diamond-like proxy pattern where each function selector maps to a specialized action facet via delegatecall. - [Protocol Contracts](https://docs.fira.money/developers/protocol-contracts.md): Protocol contracts form the core logic of the Fira protocol — the AMM, yield tokenization, router, lending markets, and supporting modules. - [Core](https://docs.fira.money/developers/protocol-contracts/core.md): The core directory contains the AMM trading infrastructure and yield tokenization system — the two pillars of the Fira protocol. - [FiraMarket](https://docs.fira.money/developers/protocol-contracts/core/fira-market.md): FiraMarket is the BT/FW AMM — it holds reserves, executes swaps, manages LP tokens, and maintains TWAP oracle state. - [FiraMarketFactory](https://docs.fira.money/developers/protocol-contracts/core/fira-market-factory.md): FiraMarketFactory deploys FiraMarket instances via split-code CREATE2 and manages fee configuration. - [MarketMathCore](https://docs.fira.money/developers/protocol-contracts/core/market-math-core.md): MarketMathCore encodes the time-decaying pricing curve and trade execution math used by FiraMarket. OracleLib provides the TWAP ring buffer. - [Lending](https://docs.fira.money/developers/protocol-contracts/lending.md): Fira's lending infrastructure includes separate markets for fixed-rate (BT-denominated) and variable-rate (USDC-denominated) lending. - [Router](https://docs.fira.money/developers/protocol-contracts/router.md): The Fira Router is a diamond-like proxy that delegates user calls to specialized action facets via selector-to-facet mappings. - [ActionSwapBT](https://docs.fira.money/developers/protocol-contracts/router/action-swap-bt.md): ActionSwapBTV3 provides entry points for swapping tokens or FW to/from Bond Tokens via the Fira Market AMM. - [ActionSwapCT](https://docs.fira.money/developers/protocol-contracts/router/action-swap-ct.md): ActionSwapCTV3 synthesizes CT swaps through the BT/FW AMM using a flash-callback pattern with BT+CT minting/redeeming. - [ActionAddRemoveLiq](https://docs.fira.money/developers/protocol-contracts/router/action-add-remove-liq.md): ActionAddRemoveLiqV3 supports 10 liquidity operation variants — dual-sided, single-sided, and keep-CT strategies for providing and removing liquidity. - [ActionBorrow](https://docs.fira.money/developers/protocol-contracts/router/action-borrow.md): ActionBorrow integrates with the lending market for fixed-rate borrowing and repayment in a single transaction. - [ActionSimple](https://docs.fira.money/developers/protocol-contracts/router/action-simple.md): ActionSimple provides gas-optimized swap and liquidity functions using on-chain approximation instead of off-chain hints. - [ActionMisc](https://docs.fira.money/developers/protocol-contracts/router/action-misc.md): ActionMiscV3 handles FW and BT+CT minting/redemption, position exits, multicall batching, and transaction simulation. - [Yield Contracts](https://docs.fira.money/developers/protocol-contracts/yield-contracts.md): Yield contracts split FW into a fixed-rate principal token (BT) and a floating-yield token (CT), minted and redeemed at the BC index rate. - [Bond Token](https://docs.fira.money/developers/protocol-contracts/yield-contracts/bond-token.md): BondToken is the fixed-rate principal token — intentionally minimal, with strict access control limiting minting to CT and the LiquidityInjector. - [Coupon Token](https://docs.fira.money/developers/protocol-contracts/yield-contracts/coupon-token.md): CouponToken is the stateful contract driving the BT/CT lifecycle — minting, redemption, interest accounting, and post-expiry behavior. - [YieldContractFactory](https://docs.fira.money/developers/protocol-contracts/yield-contracts/yield-contract-factory.md): YieldContractFactory creates BT/CT pairs for a given FW and expiry, using split-code deployment for CT. - [Rehypothecation Module](https://docs.fira.money/developers/protocol-contracts/rehypothecation-module.md): RehypothecationModule defines the idle/vault ratio parameters that control how FW tokens balance reserves and yield deployment. - [Liquidity Injector](https://docs.fira.money/developers/protocol-contracts/liquidity-injector.md): LiquidityInjector mints unbacked BT to bootstrap fixed-rate lending markets with initial loan token supply. - [Token Contracts](https://docs.fira.money/developers/token-contracts.md): Token contracts define the ERC-20 tokens used throughout the Fira protocol, including FW wrappers, BT, CT, and the custom FiraERC20 base. - [FiraERC20](https://docs.fira.money/developers/token-contracts/fira-erc20.md): FiraERC20 is the custom ERC-20 base used by every token in the protocol, providing a built-in reentrancy guard and transfer hooks. - [Bond Token](https://docs.fira.money/developers/token-contracts/bond-token.md): BondToken (BT) is the fixed-rate principal ERC-20 token with strict minting restricted to CouponToken and LiquidityInjector. - [Coupon Token](https://docs.fira.money/developers/token-contracts/coupon-token.md): CouponToken (CT) is the floating-yield ERC-20 token with built-in interest tracking and post-expiry treasury sweep. - [FW Tokens](https://docs.fira.money/developers/token-contracts/fw-tokens.md): FW token base contracts and the USDCFW implementation that wraps USDC through an ERC-4626 vault for yield generation. - [Utility Contracts](https://docs.fira.money/developers/utility-contracts.md): Utility contracts include the oracle infrastructure for pricing BT, CT, and LP tokens, and the shared math and helper libraries. - [Oracles](https://docs.fira.money/developers/utility-contracts/oracles.md): Oracle contracts provide manipulation-resistant TWAP pricing for BT, CT, and LP tokens, consumed by lending markets and external integrators. - [Solvency Oracle](https://docs.fira.money/developers/utility-contracts/oracles/solvency-oracle.md): FiraSolvencyOracle is the top layer of the fixed-rate lending oracle pipeline, providing collateral pricing to the FiraLendingMarket. - [LP Oracle](https://docs.fira.money/developers/utility-contracts/oracles/lp-oracle.md): LpOracleLib computes TWAP-based LP token prices by simulating a hypothetical rebalancing trade at the oracle-implied rate. - [BC Oracle](https://docs.fira.money/developers/utility-contracts/oracles/bc-oracle.md): BCOracleLib computes TWAP-based prices for Bond Tokens and Coupon Tokens from the FiraMarket's implied rate observations. - [Libraries](https://docs.fira.money/developers/utility-contracts/libraries.md): Shared utility and math libraries used across the Fira protocol for arithmetic, token transfers, error handling, and deployment patterns. - [Math](https://docs.fira.money/developers/utility-contracts/libraries/math.md): Fixed-point arithmetic libraries operating at 1e18 scale — the arithmetic backbone of the Fira protocol. - [Helpers](https://docs.fira.money/developers/utility-contracts/libraries/helpers.md): Helper libraries for token transfers, error definitions, ownership patterns, and the split-code deployment factory for contracts exceeding the 24KB limit. - [Contract Deployments](https://docs.fira.money/developers/deployment.md): Mainnet contract addresses, market configurations, oracle pipelines, router facets, and key roles for the Fira Protocol deployment. - [User Flows](https://docs.fira.money/developers/user-flows.md): Step-by-step user flows for every major operation in the Fira protocol, with sequence diagrams, preconditions, views, and events. - [Borrow Fixed Rate](https://docs.fira.money/developers/user-flows/borrow-fixed-rate.md): Supply collateral and borrow at a fixed rate in a single transaction, receiving USDC via the BT→FW→token path. - [Repay Fixed Rate](https://docs.fira.money/developers/user-flows/repay-fixed-rate.md): Repay fixed-rate debt using any input token, with automatic BT acquisition via AMM swap (pre-expiry) or BT+CT minting (post-expiry). - [Variable Rate Lending](https://docs.fira.money/developers/user-flows/variable-rate-lending.md): Supply collateral and borrow USDC at a variable rate directly from the lending market, or lend USDC via the SisuVault for variable yield. - [Repay Variable Rate](https://docs.fira.money/developers/user-flows/repay-variable-rate.md): Repay variable-rate USDC debt directly on the lending market. - [Trade BT/CT](https://docs.fira.money/developers/user-flows/trade-bt-ct.md): Mint BT+CT from tokens by splitting FW, and redeem BT+CT back to tokens with different handling pre- and post-expiry. - [Provide Liquidity](https://docs.fira.money/developers/user-flows/provide-liquidity.md): Provide liquidity to the BT/FW market using dual-sided, single-sided, or keep-CT strategies and receive LP tokens. - [Remove Liquidity](https://docs.fira.money/developers/user-flows/remove-liquidity.md): Burn LP tokens to withdraw proportional BT and FW from the FiraMarket pool. - [FW Deposit & Redeem](https://docs.fira.money/developers/user-flows/fw-deposit-redeem.md): Deposit tokens into FW to earn yield, and redeem FW shares back to underlying tokens. - [Pre/Post Expiry Exits](https://docs.fira.money/developers/user-flows/pre-post-expiry-exits.md): Unwind LP, BT, and CT positions to a single token or FW in one transaction, with different strategies pre- and post-expiry. - [Events & Indexing](https://docs.fira.money/developers/events-and-indexing.md): Event tracking and position measurement across Fira markets, covering the 8 role buckets and their on-chain event sources. - [Event Table](https://docs.fira.money/developers/events-and-indexing/event-table.md): Corrected event-to-role mapping for the Fira incentive indexer, with analysis of issues found in the original table. - [Position Measurement](https://docs.fira.money/developers/events-and-indexing/reward-measurement.md): Position measurement formulas and on-chain function calls for each role bucket. Technical reference for integrators tracking user exposure across Fira markets. - [Integrations](https://docs.fira.money/developers/integrations.md): A practical guide for protocols and front-ends integrating with Fira's on-chain contracts. - [Interfaces](https://docs.fira.money/developers/integrations/interfaces.md): Complete reference of all Fira Protocol Solidity interfaces, grouped by module, with key function signatures and type definitions. - [Security Practices](https://docs.fira.money/developers/security-and-audits.md): Security overview for the Fira Protocol, covering multi-layered defences baked into every contract layer. - [Security Design](https://docs.fira.money/developers/security-and-audits/security-practices.md): In-depth coverage of the security patterns and invariants enforced across the Fira Protocol smart contract stack. - [Audits](https://docs.fira.money/developers/security-and-audits/audits.md) - [Glossary](https://docs.fira.money/developers/glossary.md): Definitions of key terms, abbreviations, and concepts used throughout the Fira Protocol documentation. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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