pump-sdk-core

# Pump SDK Core — Instruction Building & On-Chain Interaction Build, extend, and maintain the core Pump SDK — an offline-first TypeScript SDK that constructs Solana `TransactionInstruction`s for token creation, buying, selling, migration, and creator fee collection across three on-chain programs (Pump, PumpAMM, PumpFees) plus the Mayhem program. ## Context The SDK is published as `@pump-fun/pump-sdk` (npm) and powers the Pump protocol — a Solana-based token launchpad with bonding curve pricing, automatic AMM migration after graduation, tiered fees, and creator fee sharing. The codebase uses Anchor for IDL-based instruction building and supports both Token (SPL) and Token-2022 token programs. ## Key Files - `src/sdk.ts` — `PumpSdk` class with all instruction builders and account decoders - `src/onlineSdk.ts` — `OnlinePumpSdk` class extending offline SDK with live RPC fetches - `src/index.ts` — barrel re-export module defining the public API surface - `src/state.ts` — TypeScript interfaces for all on-chain account state - `src/pda.ts` — Program Derived Address derivation for all programs - `src/idl/pump.ts`, `src/idl/pump_amm.ts`, `src/idl/pump_fees.ts` — Anchor IDL definitions ## Architecture - **Offline SDK (`PumpSdk`)**: Builds instructions without a live connection. Uses Anchor `Program` instances initialized with a dummy keypair and connection. Exported as a singleton `PUMP_SDK`. - **Online SDK (`OnlinePumpSdk`)**: Wraps `PumpSdk` with a real `Connection` for fetching account state via `getMultipleAccountsInfo`. Provides "BothPrograms" methods that aggregate data across bonding curve (Pump) and AMM (PumpAMM) programs. - **Three program IDs**: `PUMP_PROGRAM_ID`, `PUMP_AMM_PROGRAM_ID`, `PUMP_FEE_PROGRAM_ID`, plus `MAYHEM_PROGRAM_ID` for mayhem-mode tokens. ## Instruction Builder Pattern Every instruction method returns `TransactionInstruction[]` (not transactions), allowing callers to compose them into transactions freely. Methods follow a naming convention: - `*Instruction` — single instruction - `*Instructions` — multiple instructions (e.g., ATA creation + buy) ## Account Decoders The SDK decodes raw `AccountInfo<Buffer>` into typed interfaces using the Anchor coder: - `decodeGlobal`, `decodeBondingCurve`, `decodeFeeConfig`, `decodeSharingConfig`, etc. - Nullable variants (e.g., `decodeBondingCurveNullable`) handle missing or undersized accounts gracefully. ## Slippage Calculation ``` maxSolCost = solAmount + (solAmount × slippage × 10 / 1000) minSolReceived = solAmount - (solAmount × slippage × 10 / 1000) ``` ## Patterns to Follow - Always return `TransactionInstruction[]` from instruction builders, never full `Transaction` objects - Use `getMultipleAccountsInfo` to batch RPC calls (2–3 accounts per call) - Support both Token (SPL) and Token-2022 programs via `tokenProgram` parameter - Handle account extension (`extendAccountInstruction`) for bonding curves that need more space - Validate shareholder arrays: max 10 shareholders, shares must total 10,000 bps, no duplicates, no zero shares - Use typed error classes from `src/errors.ts` for validation failures - Keep the offline SDK connection-free; all RPC calls belong in `OnlinePumpSdk` ## Common Pitfalls - Circular dependency between `sdk.ts` and `onlineSdk.ts` - Buy instruction passes `{ 0: true }` as a flags argument — this is intentional, not a bug - `BONDING_CURVE_NEW_SIZE = 151` — accounts may need extension before certain operations - `BondingCurve.complete === true` means the token has graduated to AMM — bonding curve operations will fail - The `createInstruction` (v1) is deprecated in favor of `createV2Instruction` (Token-2022)