fynd 0.62.0

High-performance DeFi route-finding engine — embeddable library and CLI
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Fynd

A high-performance DeFi route-finding engine built on Tycho. Finds optimal swap routes across multiple DeFi protocols in real-time.

Features

  • Multi-protocol routing - Routes through your favorite on-chain liquidity protocol, like Uniswap, Balancer, Curve, RFQ protocols, or any other protocol supported by Tycho.
  • Real-time market data - Tycho Stream keeps all liquidity states synchronized every block
  • Multi-algorithm competition - Multiple solver pools run different algorithm configurations in parallel; the best result wins
  • Gas-aware ranking - Solutions are ranked by net output after gas costs, not just raw output
  • Sub-100ms solves - Dedicated OS threads for CPU-bound route finding, separate from the async I/O runtime
  • Production-ready - Prometheus metrics, structured logging, health endpoints, graceful shutdown
  • Extensible - Implement the Algorithm trait to add new routing strategies with zero framework changes
  • Modular - Use just the core solving logic, or build a custom HTTP server with your own middleware

Prerequisites

Quickstart

cargo install fynd
export TYCHO_API_KEY=your-api-key
export RUST_LOG=fynd=info
fynd serve

The solver starts on http://localhost:3000. Request a quote:

curl -X POST http://localhost:3000/v1/quote \
  -H "Content-Type: application/json" \
  -d '{
    "orders": [
      {
        "token_in": "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2",
        "token_out": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
        "amount": "1000000000000000000",
        "side": "sell",
        "sender": "0x0000000000000000000000000000000000000001"
      }
    ],
    "options": { "timeout_ms": 5000 }
  }'

Run on a specific chain

You can run on any chain supported by Tycho (see Tycho Hosted endpoints):

export RPC_URL=<RPC_FOR_TARGET_CHAIN>
cargo run --release serve --chain base

See the full quickstart for Docker, build-from-source, and client SDK examples (Rust & TypeScript).

Build features

The fynd binary exposes the following Cargo features:

Feature Default What it enables
metrics on Prometheus /metrics endpoint on a separate HTTP server (port 9898). Pulls in Actix-Web. 
# Default build (metrics on)
cargo install fynd
cargo build --release

# Build without the metrics exporter (smaller binary, no /metrics endpoint)
cargo install fynd --no-default-features
cargo build --release --no-default-features

Documentation

For API reference, configuration options, encoding, client fees, custom algorithms, architecture, and more, visit the full documentation at docs.fynd.xyz.

Packages

Fynd is organized into three crates:

  • fynd — Complete CLI application that runs an HTTP RPC server. Use this to run Fynd as a standalone service.
  • fynd-core — Pure solving logic with no HTTP dependencies. Use this if you want to integrate Fynd's routing algorithms into your own application.
  • fynd-rpc — HTTP RPC server builder with customizable middleware. Use this to build a custom HTTP server with your own configuration.

Client SDKs that handle quoting, token approvals, and swap execution end-to-end: