# Aspens SDK
[](https://crates.io/crates/aspens)
[](https://docs.rs/aspens)
A comprehensive SDK and CLI tools for interacting with an [Aspens Markets Stack](https://docs.aspens.xyz).
The core library is published on crates.io as [`aspens`](https://crates.io/crates/aspens).
The `aspens-cli`, `aspens-repl`, and `aspens-admin` binaries live in this
workspace and are built from source.
## Available Commands
| `config` | Fetch and display the configuration from the server |
| `deposit <network> <token> <amount>` | Deposit tokens to make them available for trading |
| `withdraw <network> <token> <amount>` | Withdraw tokens to a local wallet |
| `buy-market <market> <amount>` | Send a market BUY order (executes at best available price) |
| `buy-limit <market> <amount> <price> [--post-only]` | Send a limit BUY order (executes at specified price or better). With `--post-only`, the order is rejected if it would cross at submission — guarantees maker-side execution. |
| `sell-market <market> <amount>` | Send a market SELL order (executes at best available price) |
| `sell-limit <market> <amount> <price> [--post-only]` | Send a limit SELL order (executes at specified price or better). See `--post-only` above. |
| `cancel-order <market> <side> <order_id>` | Cancel an existing order by its ID |
| `stream-orderbook <market> [--historical] [--trader <addr>]` | Stream orderbook entries in real-time |
| `stream-trades <market> [--historical] [--trader <addr>]` | Stream executed trades in real-time |
| `balance` | Fetch the current balances for all supported tokens across all chains |
| `status` | Show current configuration and connection status |
| `trader-public-key` | Get the public key and address for the trader wallet |
| `signer-public-key [--chain-id <id>]` | Get the signer public key(s) for the trading instance |
All commands are available in both `aspens-cli` and `aspens-repl`.
## Project Structure
This is a Cargo workspace with four main components:
- **`aspens/`** - Core Rust library crate with trading logic and gRPC client
- **`aspens-cli/`** - Command-line interface binary for scripted operations
- **`aspens-repl/`** - Interactive REPL binary for manual trading
- **`aspens-admin/`** - Administrative CLI for stack configuration (chains, tokens, markets)
## Prerequisites
1. **Install Rust:**
```bash
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
```
2. **Install Just (Optional but Recommended):**
[Just](https://github.com/casey/just) is a command runner that simplifies common development tasks.
```bash
brew install just # macOS
cargo install just # Any platform
```
3. **Configure environment:**
```bash
cp .env.sample .env ```
## Building
```bash
just build # Build entire workspace
just release # Build release version
just build-lib # Build core library only
just build-cli # Build CLI only
just build-repl # Build REPL only
just build-admin # Build Admin CLI only
```
## Usage
### 1. As a Rust Library
Install from crates.io:
```bash
cargo add aspens
```
Or add it manually to your `Cargo.toml`:
```toml
[dependencies]
aspens = "0.4"
```
Full client (gRPC + trading commands + RPC submission):
```rust
use aspens::{AspensClient, DirectExecutor};
#[tokio::main]
async fn main() -> eyre::Result<()> {
let client = AspensClient::builder()
.with_url("http://localhost:50051")?
.build()?;
// Use trading operations...
Ok(())
}
```
Stateless signing only (no gRPC, no tokio, no RPC client — e.g. browser
via `wasm-bindgen`, edge workers, or a service that submits orders over
its own transport):
```bash
cargo add aspens --no-default-features --features evm,solana
```
```toml
[dependencies]
aspens = { version = "0.4", default-features = false, features = ["evm", "solana"] }
```
```rust
use aspens::orders::{derive_order_id, GaslessLockParams};
use aspens::evm::gasless_lock_signing_hash;
use aspens::solana::{gasless_lock_signing_message, OpenOrderArgs};
// Build the canonical order id from a few intent fields:
let order_id = derive_order_id(
&user_pubkey_bytes, nonce, origin_chain, dest_chain,
&input_token_bytes, &output_token_bytes, amount_in, amount_out,
);
// EVM: produce the EIP-712 digest a wallet must sign for a gasless lock.
let digest = gasless_lock_signing_hash(¶ms, arborter, settler, chain_id)?;
// Solana: produce the borsh payload for Ed25519 signing of a gasless open.
let msg = gasless_lock_signing_message(&instance, &user, deadline, &order)?;
```
The pure modules:
- **`aspens::orders`** — chain-agnostic `derive_order_id`, `GaslessLockParams`.
- **`aspens::evm`** — sol! bindings for `MidribV2` / `IAllowanceTransfer` /
`MidribDataTypes`, EIP-712 domain consts, gasless-order builder and hasher,
EIP-191 envelope signer.
- **`aspens::solana`** — PDA derivations, instruction builders, borsh payload
encoder, Ed25519 precompile ix, well-known program ids.
### 2. Interactive Mode (REPL)
```bash
cargo run --bin aspens-repl
# Inside the REPL
aspens> help
aspens> balance
aspens> deposit base-sepolia USDC 1000
aspens> buy-market USDC/USDT 100
aspens> quit
```
### 3. Scripted Mode (CLI)
```bash
cargo run --bin aspens-cli -- balance
cargo run --bin aspens-cli -- deposit base-sepolia USDC 1000
cargo run --bin aspens-cli -- buy-market USDC/USDT 100
```
### Post-only orders
Pass `--post-only` to `buy-limit` / `sell-limit` to guarantee your order
adds liquidity rather than taking it. If the price would cross the
opposing side of the book at submission, arborter returns
`FAILED_PRECONDITION` and **does not** lock funds on-chain — no gas is
spent and your gasless signature stays unused, so you can resubmit at a
different price.
```bash
# Post a maker-only bid at 100. If the best ask is ≤ 100, the order
# is rejected and you can retry at 99 (or below).
aspens-cli buy-limit USDC/USDT 1.5 100 --post-only
# Same on the sell side: rejected if there's a resting bid at ≥ 200.
aspens-cli sell-limit USDC/USDT 1.5 200 --post-only
```
In Rust:
```rust
use aspens::commands::trading::send_order;
let response = send_order::send_order_with_wallet(
stack_url,
market_id,
1, // 1 = BUY
"1.5".into(), // quantity
Some("100".into()), // limit price (required for post-only)
&wallet,
config,
true, // post_only
).await?;
```
Post-only is incompatible with market orders (the SDK pre-rejects
`post_only=true` with `price=None` before signing) and with the
`buy-marketable` / `sell-marketable` CLI variants (which are designed
to cross — the CLI hard-codes `post_only=false` for them).
### 4. Admin CLI
```bash
# Initialize admin (first time only)
cargo run --bin aspens-admin -- init-admin --address 0xYourAddress
# Login to get JWT
cargo run --bin aspens-admin -- login
# Admin commands (JWT set in .env or via --jwt flag)
cargo run --bin aspens-admin -- set-chain --network base-sepolia ...
cargo run --bin aspens-admin -- set-token --network base-sepolia --symbol USDC ...
cargo run --bin aspens-admin -- status
```
## Cargo Feature Flags
The `aspens` crate exposes three orthogonal feature groups, all
default-on. Consumers can trim down to just what they need:
| `evm` | `aspens::evm` (sol! bindings, EIP-712 hasher, envelope signer) + `aspens::orders`. Tiny — `alloy-primitives`/`alloy-sol-types`/`alloy-signer-local`. | Keep if you build or sign EVM orders. |
| `solana` | `aspens::solana` (PDA derivations, instruction builders, borsh payload encoder, Ed25519 precompile ix). Pulls `solana-sdk`, `borsh`, `bs58`, `ed25519-dalek`. | Keep if you build or sign Solana orders. |
| `client` | Full runtime: `AspensClient`, trading commands, gRPC (`tonic`/`prost`), async runtime (`tokio`), RPC submission (`solana-client`, `alloy-contract`, `alloy-provider`). | Keep for the CLI/REPL/admin experience or anything that talks to the Aspens stack. Drop it for browser / embedded / offline-signing. |
Common configurations:
- **Default** (everything): `aspens = "0.4"`
- **Lean EVM signing**: `aspens = { version = "0.4", default-features = false, features = ["evm"] }`
- **Lean Solana signing**: `aspens = { version = "0.4", default-features = false, features = ["solana"] }`
- **Both chains, no client runtime**: `aspens = { version = "0.4", default-features = false, features = ["evm", "solana"] }`
The `aspens-cli`, `aspens-repl`, and `aspens-admin` binaries all depend
on the default feature set.
## Just Commands
```bash
just # List all available commands
just build # Build the project
just test # Run all tests
just test-lib # Run library tests only
just fmt # Format code
just check # Check code style
just lint # Run linter
just clean # Clean build artifacts
```
## Architecture
### Core Library (`aspens/`)
- **AspensClient** - Main client with builder pattern for configuration
- **Trading operations** - Deposit, withdraw, buy, sell, balance queries across EVM and Solana chains
- **Curve-agnostic wallet** - `Wallet::Evm` (secp256k1) and `Wallet::Solana` (Ed25519) behind one signing interface
- **Chain dispatch** - `ChainClient` routes RPC calls to Alloy (EVM) or `solana-client` based on chain architecture
- **Executor pattern** - Async/sync execution strategies
- **gRPC client** - Protocol buffer communication with an Aspens Market Stack
- **Client-side order helpers** (`aspens::orders` / `aspens::evm` / `aspens::solana`) — stateless
builders for the gRPC order payload: `derive_order_id`, EIP-712 gasless-lock hasher (EVM),
borsh `OpenForSignedPayload` encoder (Solana), PDA derivations, Ed25519 precompile ix.
Available without the `client` feature for browser / embedded callers.
- **EVM integration** - Midrib V2 ABI bindings (shared JSON artifacts with arborter), Alloy signer, Permit2
- **Solana integration** - Midrib Anchor program: Anchor discriminators, PDA seeds, SPL token flow
### CLI Binary (`aspens-cli/`)
Command-line interface for scripted trading operations.
### REPL Binary (`aspens-repl/`)
Interactive Read-Eval-Print Loop for manual trading with command history and session state.
### Admin Binary (`aspens-admin/`)
Administrative CLI for managing stack configuration with EIP-712 signature authentication.
## Decimal Handling
Aspens handles tokens with different decimal places across chains. The SDK works in "pair decimals" format internally. See `decimals.md` for detailed conversion examples.
## Token Assumptions
**Important:** Aspens only supports tokens with **standard ERC-20 / SPL semantics**. Adding a non-compliant token to a market — via `aspens-admin set-token` or the admin-console — will produce incorrect balances, fee leakage, or stuck funds. The contracts do **not** detect non-compliant tokens; gating happens here, in market configuration.
A token is safe to add **only if all of the following hold**:
- **Standard transfer semantics.** A `transfer(to, amount)` reduces the sender's balance by exactly `amount`. No transfer hooks that re-enter or opportunistically revert.
- **No fee-on-transfer.** Tokens that charge a fee on transfer (reflection tokens, deflationary tokens) silently shift cost onto the user's existing `tradeBalance` during `_depositAndLock`, cause the Aspens vault to under-collect fees, and under-deliver `SETTLE_AND_WITHDRAW` payouts.
- **No rebasing.** Tokens whose balances change between two reads of `balanceOf` (AMPL-style, aTokens in rebase mode) break the `balanceBefore`/`balanceAfter` reconciliation used throughout the contract. Use the wrapped, non-rebasing variant (e.g. wstETH, not stETH).
- **No supply-pause that strands open orders.** Pausable tokens are tolerable as long as pauses are short-lived; pauses of a duration longer than the cancel-and-unlock window can strand `lockedTradeBalance` until the pause lifts.
- **Blocklist tokens (USDC-style) are accepted with caveats.** Funds remain correctly accounted for, but a blocklisted address cannot withdraw or settle out until removed from the list.
Quick checklist before running `aspens-admin set-token`:
1. Read the token's `transfer` implementation — confirm `_balances[from] -= amount` is the only debit.
2. Run a probe transfer (any amount) and check `balanceAfter == balanceBefore - amount` on both sides.
3. Confirm `balanceOf` is a pure function of stored state, not a function of total supply.
If any of these checks fails, **do not add the token**. Common safe examples: USDC, USDT (on chains where USDT does not enable fee-on-transfer), WBTC, WETH, DAI, most stablecoins.
### Solana-specific notes
The on-chain `midrib` program uses the **legacy SPL Token program**, not Token-2022. Mints owned by the Token-2022 program (`TokenzQdBNbLqP5VEhdkAS6EPFLC1PHnBqCXEpPxuEb`) will fail deserialization at every entry point — by design, since Token-2022's transfer-fee, interest-bearing, and confidential-transfer extensions would all break the program's `deposited += amount` accounting.
For gasless `open_for` flows the user signs an `OpenForSignedPayload` with an `args.deadline` slot. Pick this tight — `current_slot + 600` (~4 minutes at 400ms slots) is a sensible default. The on-chain `UsedNonce` tombstone guarantees a signed payload is single-use regardless of deadline, but a tight deadline limits the window between user-signs and arborter-submits.
## Documentation
- [Decimal Conversion Guide](decimals.md) - Understanding decimal handling
- [CHANGELOG.md](CHANGELOG.md) - Release notes per version
- [CLAUDE.md](CLAUDE.md) - Architecture guide for development
## Versioning
The `aspens` crate follows [Semantic Versioning](https://semver.org/). The
workspace is pre-1.0, so the conventions in effect today are:
- **Patch releases (`0.4.x` → `0.4.y`)** — bug fixes, performance work,
internal refactors. No source-breaking changes to public items in
`aspens::{client, wallet, orders, evm, solana, decimals}` or to the
re-exports at the crate root.
- **Minor releases (`0.4.x` → `0.5.0`)** — may include breaking changes
to the public API surface (renames, signature changes, removals).
Notable changes are recorded in [`CHANGELOG.md`](CHANGELOG.md).
- **Internal modules** — `aspens::grpc` (and any module marked
`#[doc(hidden)]` or `pub(crate)`) are implementation details and may
change in any release. Generated proto bindings under
`aspens::proto::*` and `aspens::attestation::*` track the upstream
`protos/` repo and follow its compatibility, not the SDK's.
- **CLI / REPL / Admin binaries** — version-bumped together with the
library. Flag and command renames are called out in `CHANGELOG.md`.
When in doubt about whether a change is breaking, check the changelog
entry for the target version.
## License
This project is licensed under the Apache License 2.0. See the [LICENSE](LICENSE) file for details.