Lintent is LI.FI's interactive demo for the Open Intents Framework (OIF). It walks through the full cross-chain intent lifecycle, from resource lock management and intent issuance to solving, proof submission, and finalisation. The live app is hosted at lintent.org.

The app handles both sides of an intent: the user (intent issuer) and the solver. Each step maps to a dedicated screen so you can follow the entire flow in sequence.

Architecture

flowchart TD
    subgraph Browser["Browser (SvelteKit SPA)"]
        direction TB
        Page["+page.svelte"]
        S0["Connect Wallet"]
        S1["Manage Deposit"]
        S2["Issue Intent"]
        S3["Intent List"]
        S4["Fill Intent"]
        S5["Receive Message"]
        S6["Finalise"]

        Store["Svelte 5 runes store\nbalances, allowances, orders"]
        DB["PGlite via IndexedDB\nintents, fills, receipts"]

        Page --> S0 & S1 & S2 & S3 & S4 & S5 & S6
        Store --> DB
    end

    subgraph Worker["Cloudflare Worker"]
        API_P["POST /polymer\nproof proxy"]
        API_A["POST /allocator\nallocator proxy"]
        API_H["GET /health"]
    end

    subgraph External["External Services"]
        OS["LI.FI Order Server\nREST + WebSocket"]
        POL["Polymer API\ncross-chain proofs"]
        RPC["EVM RPC Nodes"]
    end

    subgraph Contracts["Smart Contracts"]
        COMPACT["The Compact\nresource lock registry"]
        ESC["Input Settler\nescrow + multichain"]
        CSETT["Input Settler\ncompact + multichain"]
        CF["CoinFiller\noutput settlement"]
        PORACLE["Polymer Oracle\nproof verifier"]
    end

    S2 -->|"getQuotes / submitOrder"| OS
    S3 -->|"WebSocket + REST"| OS
    S4 -->|"fillOrderOutputs"| CF
    S5 -->|"proof request"| API_P
    S5 -->|"receiveMessage"| PORACLE
    S5 -->|"setAttestation"| CF
    S6 -->|"finalise"| ESC
    S6 -->|"finalise"| CSETT
    S1 -->|"deposit / withdraw"| COMPACT
    S2 -->|"open escrow"| ESC
    S2 -->|"sign compact"| COMPACT
    API_P -->|"requestProof / queryProof"| POL
    API_A -->|"attestCommit"| POL
    Store -->|"balance / allowance reads"| RPC

Intent Lifecycle

The app exposes six sequential screens, each representing one step in the OIF flow.

• Connect Wallet connects via Web3-Onboard (injected wallets, Coinbase, WalletConnect, Zeal)
• Manage Deposit lets you choose between escrow and compact locking, then deposit or withdraw tokens from The Compact
• Issue Intent configures the intent (input/output tokens, chains, amounts, verifier), fetches a quote from the LI.FI order server, and submits the order on-chain (escrow) or via EIP-712 signature (compact)
• Intent List shows open intents from the order server WebSocket and local DB, with the option to import by on-chain order ID
• Fill Intent is the solver side, where output tokens are delivered to recipients via the CoinFiller contract on each output chain
• Receive Message fetches a cross-chain proof from Polymer and submits it to the Polymer Oracle on the source chain (or calls setAttestation for same-chain fills)
• Finalise calls finalise() on the appropriate input settler, releasing the locked input tokens to the solver

Tech Stack

• Framework SvelteKit 2 with Svelte 5 runes
• Language TypeScript
• Styling Tailwind CSS v4
• EVM viem ~2.45
• Wallet Web3-Onboard
• Local DB PGlite (WASM Postgres) + Drizzle ORM, persisted to IndexedDB
• Deployment Cloudflare Workers via @sveltejs/adapter-cloudflare
• Runtime Bun
• Testing Bun test (unit/integration) and Playwright (E2E)

Supported Chains

Mainnet Ethereum, Base, Arbitrum, Polygon, BSC, MegaETH, Katana

Testnet Sepolia, Base Sepolia, Arbitrum Sepolia, Optimism Sepolia

Smart Contracts

The app interacts with the following deployed contracts (ABIs are inlined in src/lib/abi/).

Project Structure

src/
  lib/
    abi/              # contract ABIs (Compact, Escrow, CoinFiller, Polymer Oracle, etc.)
    libraries/        # core logic (Intent, IntentFactory, OrderServer, Solver, CompactLib)
    screens/          # SvelteKit components for each step in the flow
    utils/            # helpers (EIP-712 typed data, order validation, address encoding)
    config.ts         # contract addresses, chain config, token lists, RPC clients
    state.svelte.ts   # global reactive store (Svelte 5 runes)
    db.ts             # PGlite + Drizzle init with IndexedDB persistence
    schema.ts         # Drizzle table definitions
  routes/
    +page.svelte      # single-page entry point (renders all six screens)
    polymer/          # server route proxying to Polymer API
    allocator/        # server route proxying to Polymer Allocator
    health/           # liveness check
tests/
  unit/               # order validation, intent list, order server parsing, asset selection
  e2e/                # Playwright browser tests for issuance flow
  db.test.ts          # PGlite integration test

Getting Started

1. Copy .env.example to .env
2. Create a WalletConnect project and add the project ID
3. Create an account with Polymer and generate API keys for mainnet and testnet
4. Install dependencies with bun install
5. Start the dev server with bun run dev

Testing

• bun run test:unit runs library and unit tests with coverage
• bun run test:e2e runs Playwright browser tests (requires bunx playwright install chromium)
• bun run test:all runs both suites

Deployment

Production deploys happen on push to main via GitHub Actions. The workflow builds with Bun and deploys to the lintent-worker Cloudflare Worker. PR preview environments are created and cleaned up automatically.

Required secrets for CI: CLOUDFLARE_API_TOKEN, CLOUDFLARE_ACCOUNT_ID, PRIVATE_POLYMER_MAINNET_ZONE_API_KEY, PRIVATE_POLYMER_TESTNET_ZONE_API_KEY, PUBLIC_WALLET_CONNECT_PROJECT_ID.

License

This project is licensed under the MIT License.