Orderbook

On-chain limit order book with bid/ask matching

Pending Anchor 0.32

Program ID 41q8aXfcpqREjcFRK276KzBRRXWvmfYGqCDHZQ4CPwnX

Repository ExpertVagabond/solana-orderbook

Binary Size 273K

Cluster Devnet

Instructions

IX initialize_market

Creates a new trading market for a base/quote token pair with a configurable fee.

Parameter	Type	Description
`fee_bps`	`u16`	Trading fee in basis points (1 bps = 0.01%)

IX place_order

Places a new limit order on the book at the specified price and quantity.

Parameter	Type	Description
`side`	`Side`	Order side: `Bid` or `Ask`
`price`	`u64`	Limit price in quote token units
`quantity`	`u64`	Order quantity in base token units

IX fill_order

Fills an existing order, partially or completely, transferring tokens between parties.

Parameter	Type	Description
`quantity`	`u64`	Amount to fill from the existing order

IX cancel_order

Cancels an open order and returns unfilled tokens to the owner.

Parameter	Type	Description
No parameters

Accounts

Market

Field	Type	Description
`authority`	`Pubkey`	Market creator and fee authority
`base_mint`	`Pubkey`	Mint address of the base token
`quote_mint`	`Pubkey`	Mint address of the quote token
`fee_bps`	`u16`	Trading fee in basis points
`order_count`	`u64`	Total number of orders placed
`bump`	`u8`	PDA bump seed

Order

Field	Type	Description
`market`	`Pubkey`	The market this order belongs to
`owner`	`Pubkey`	Wallet that placed the order
`id`	`u64`	Sequential order identifier
`side`	`Side`	Order side (Bid or Ask)
`price`	`u64`	Limit price in quote units
`quantity`	`u64`	Total order quantity
`filled`	`u64`	Amount already filled
`timestamp`	`i64`	Unix timestamp when the order was placed
`bump`	`u8`	PDA bump seed

Enum: Side

Variant	Description
`Bid`	Buy order - offering quote tokens to receive base tokens
`Ask`	Sell order - offering base tokens to receive quote tokens

PDA Derivation

market

seeds = [b"market", authority, base_mint, quote_mint]

order

seeds = [b"order", market, order_count.to_le_bytes()]

Error Codes

InvalidSide The order side must be either Bid or Ask

InsufficientQuantity The fill quantity exceeds the remaining unfilled amount

OrderFilled The order has already been completely filled

PriceMismatch The fill price does not match the order limit price

Overflow Arithmetic overflow in token amount calculation

Usage Example

import { Program, AnchorProvider, BN } from "@coral-xyz/anchor";
import { PublicKey } from "@solana/web3.js";

// Derive the market PDA
const [marketPda] = PublicKey.findProgramAddressSync(
  [Buffer.from("market"), authority.publicKey.toBuffer(), baseMint.toBuffer(), quoteMint.toBuffer()],
  program.programId
);

// Place a bid order
await program.methods
  .placeOrder({ bid: {} }, new BN(100_000), new BN(50))
  .accounts({
    market: marketPda,
    owner: trader.publicKey,
    baseMint,
    quoteMint,
  })
  .signers([trader])
  .rpc();

Solana Programs