# Velocity Rust SDK

> Canonical: https://docs.velocity.exchange/developers/velocity-rs

`velocity-rs` is the Rust client for the Velocity program. It derives accounts, builds and signs instructions, and keeps a live cache of onchain state that application code reads through accessors instead of round-tripping to RPC on every decision. It is the SDK the protocol's own keeper and Swift services are built on, and it is written for processes that run continuously: market making bots, fillers, liquidators, orderbook servers.

For a front end, a script, or anything that makes a handful of calls per minute, the [TypeScript SDK](/developers/velocity-sdk.md) is the shorter path. Reach for `velocity-rs` when the integration needs a locally maintained orderbook, a gRPC account feed, or fill decisions inside a single slot.

> **Warning:**
>
> `velocity-rs` is not published to crates.io, and there is no `docs.rs` page for it. It is consumed as a git dependency on the `velocity-v1` monorepo, which is itself private until after the audit. `cargo add velocity-rs` will not resolve, and neither will a public clone. Without access to the monorepo, these pages describe what the crate does, but building against it is not yet possible. [Setup](/developers/velocity-rs/setup.md) has the dependency line for whenever access is available.

## Where to start

Read [Setup](/developers/velocity-rs/setup.md) first. Two of its constraints are hard failures rather than inconveniences: an Apple Silicon machine needs an x86_64 toolchain under Rosetta, and an application already pinned to `solana-sdk` 1.x or 2.x will not typecheck against this crate's 3.x types.

Then read [The client](/developers/velocity-rs/client.md). Almost everything else on these pages assumes a subscribed `VelocityClient`, and the difference between a WebSocket subscription and a gRPC subscription changes what the rest of a bot can assume about freshness.

## In this section

## What the crate re-exports

`velocity-rs` is the single point in the workspace that depends on the onchain program crate, and it re-exports it as `velocity_rs::program`. Program math, controller, state, error, and sdk modules are reachable through that path. This is deliberate: downstream consumers reach program internals through the SDK rather than taking a second path dependency on the program, so there is exactly one version of those types in a build.

The Solana crates it is built on are re-exported too, so a consumer normally does not name them directly. `velocity_rs::RpcClient` is `solana_rpc_client::nonblocking::rpc_client::RpcClient`, `velocity_rs::Pubkey` is `solana_pubkey::Pubkey`, and `velocity_rs::types::solana_sdk` gathers the account, clock, commitment, instruction, message and signature types under one module path.

IDL-derived account and instruction types live in `velocity_rs::velocity_idl`, generated from the same canonical IDL the TypeScript SDK uses. [Setup](/developers/velocity-rs/setup.md#idl-derived-types) covers how they stay in sync.