Lifi

LI.FI Cross-Chain Integration Guide

Use LI.FI when a Solana app, wallet, backend, or AI agent needs cross-chain token transfers, bridge aggregation, same-chain swaps, payment flows, or transfer status tracking. LI.FI exposes the same routing engine through REST API, SDK, MCP server, CLI, and Widget surfaces.

Overview

LI.FI is a multi-chain liquidity aggregation platform for swaps and bridging. For agent and backend integrations, the REST API is the lowest-dependency default. For frontend apps, prefer the SDK because it handles wallets, signing, execution tracking, and ecosystem-specific transaction handling. For MCP-compatible AI hosts, prefer the LI.FI MCP server for typed tool discovery.

Core capabilities:

• Quotes: Get a ready-to-sign transaction for the best route.
• Routes: Compare multiple route options and execute step-by-step.
• Status tracking: Track source and destination chain transfer progress.
• Discovery: Query supported chains, tokens, bridges, and exchanges at runtime.
• Solana support: Request Solana-specific chain/token data via chainTypes=SVM and use SOL as the Solana chain key in API examples.

Product Surface Selection

Choose the smallest surface that matches the task:

• REST API: Backend services, scripts, and general AI agents. Simple HTTP calls, no runtime dependency.
• SDK (@lifi/sdk): Frontend or full execution flows. Handles wallet connectors, signing, route execution, and update hooks.
• MCP Server: MCP-compatible AI hosts such as Claude, Cursor, or Windsurf. Use when typed tool discovery is available.
• CLI: Token-efficient agent workflows where compact human-readable output is preferable to raw JSON.
• Widget: Ready-made UI when the user wants embedded swap/bridge UX rather than custom integration.

Do not force every integration through the SDK. For quote lookup, route comparison, or status checks, the API is often simpler and easier to audit.

Base URLs and Authentication

Production API: https://li.quest/v1
Staging API:    https://staging.li.quest/v1
Docs:           https://docs.li.fi
OpenAPI:        https://docs.li.fi/openapi.yaml
LLM overview:   https://docs.li.fi/llms.txt

LI.FI APIs can be used without an API key. Use an API key for higher rate limits or authenticated partner usage. Register an integration in the LI.FI Partner Portal to get an API key: https://portal.li.fi/

For direct REST calls, pass the key in the x-lifi-api-key header:

curl 'https://li.quest/v1/chains?chainTypes=EVM,SVM' \
  --header 'accept: application/json' \
  --header 'x-lifi-api-key: YOUR_API_KEY_IF_AVAILABLE'

Test a key server-side before using it in production:

curl 'https://li.quest/v1/keys/test' \
  --header 'x-lifi-api-key: YOUR_API_KEY'

Never expose x-lifi-api-key in browser code, public repositories, or direct Widget configuration. If using the SDK from a backend or trusted runtime, pass the key through createConfig({ apiKey: '...' }); if using the Widget in a frontend, do not pass an API key.

Integration Workflow

1. Clarify the transfer intent

   • Source chain, destination chain, source token, destination token.
   • Amount in the token's smallest unit.
   • Sender address and, when different, recipient address.
   • Whether the user wants a single best route or route comparison.

2. Discover support instead of hardcoding

   • Use /chains to verify chains.
   • Use /tokens or /token to verify token addresses and decimals.
   • Use /tools to list current bridges and exchanges.
   • Do not assume every token, bridge, or chain pair is available.

3. Choose quote vs routes

   • Use GET /quote for a simple transfer where the best executable route is enough.
   • Use POST /advanced/routes when comparing alternatives or when the user asks for route choice, cost, speed, tool allowlists, or multiple steps.
   • Use POST /advanced/stepTransaction to populate transaction data for individual route steps when executing advanced routes.

4. Show the user what they will sign

   • Summarize from-chain, to-chain, from-token, to-token, amount, estimated output, tool/bridge, fees, recipient, and slippage.
   • Never ask a user to sign opaque transaction data without a human-readable summary.

5. Execute through the appropriate wallet path

   • If using GET /quote, the response already includes transactionRequest; after allowance/permit handling, submit that transaction with the source-chain wallet.
   • If using POST /advanced/routes, first choose a route, then populate each step with POST /advanced/stepTransaction before execution.
   • EVM transaction requests usually include fields such as to, data, value, and gas fields.
   • Solana-originating transfers return Solana transaction data as base64 in transactionRequest.data; deserialize, sign, and send through the user's Solana wallet or SDK path.
   • Prefer SDK executeRoute for production multi-step execution because it manages allowance and balance checks, chain switching, transaction data retrieval, transaction submission, and status tracking.
   • Never mutate transactionRequest.data, calldata, recipient, refund, memo, or bridge-specific payloads after receiving them from LI.FI.

6. Track status after source-chain submission

   • Poll /status every 10-30 seconds until terminal status.
   • Include fromChain, toChain, and bridge from the quote when available to speed up lookup.
   • Treat source-chain confirmation as only the start of a cross-chain transfer, not proof of final delivery.

Minimal Endpoint Set

Get a quote

Use for a single best route with transaction data included.

curl --request GET \
  --url 'https://li.quest/v1/quote?fromChain=ARB&toChain=SOL&fromToken=0xaf88d065e77c8cC2239327C5EDb3A432268e5831&toToken=7vfCXTUXx5WJV5JADk17DUJ4ksgau7utNKj4b963voxs&fromAddress=YOUR_EVM_WALLET&toAddress=YOUR_SOL_WALLET&fromAmount=1000000000' \
  --header 'accept: application/json'

Required parameters:

• fromChain: source chain ID or key.
• toChain: destination chain ID or key.
• fromToken: source token symbol or address.
• toToken: destination token symbol or address.
• fromAmount: amount in smallest unit.
• fromAddress: sender wallet address.
• toAddress: recipient wallet address when different from sender or when bridging across ecosystems.

Get multiple routes

Use when the user asks to compare routes or when the application needs route selection.

curl --request POST \
  --url 'https://li.quest/v1/advanced/routes' \
  --header 'accept: application/json' \
  --header 'content-type: application/json' \
  --data '{
    "fromChainId": "ARB",
    "toChainId": "SOL",
    "fromTokenAddress": "0xaf88d065e77c8cC2239327C5EDb3A432268e5831",
    "toTokenAddress": "7vfCXTUXx5WJV5JADk17DUJ4ksgau7utNKj4b963voxs",
    "fromAmount": "1000000000",
    "fromAddress": "YOUR_EVM_WALLET",
    "toAddress": "YOUR_SOL_WALLET"
  }'

Check transfer status

curl --request GET \
  --url 'https://li.quest/v1/status?txHash=SOURCE_TX_HASH&fromChain=ARB&toChain=SOL&bridge=BRIDGE_KEY' \
  --header 'accept: application/json'

Status handling:

• NOT_FOUND: Transaction may not be indexed or mined yet. Retry with fromChain and bridge if known.
• PENDING: Continue polling.
• DONE + COMPLETED: Successful final delivery.
• DONE + PARTIAL: Successful but output token may differ while preserving value semantics.
• DONE + REFUNDED: Transfer failed but funds were refunded.
• FAILED: Stop polling and surface the error/substatus.

List supported chains

curl --request GET \
  --url 'https://li.quest/v1/chains?chainTypes=EVM,SVM' \
  --header 'accept: application/json'

Solana-only:

curl --request GET \
  --url 'https://li.quest/v1/chains?chainTypes=SVM' \
  --header 'accept: application/json'

List Solana tokens

curl --request GET \
  --url 'https://li.quest/v1/tokens?chains=SOL&chainTypes=SVM' \
  --header 'accept: application/json'

List bridges and exchanges

curl --request GET \
  --url 'https://li.quest/v1/tools' \
  --header 'accept: application/json'

Solana-Specific Guidance

Use this section whenever either side of the transfer is Solana.

• Use chainTypes=SVM when querying Solana chain support.
• Use SOL as the Solana chain key in API examples.
• Always pass a Solana toAddress when bridging from an EVM chain to Solana; the sender's EVM address is not a valid Solana recipient.
• For SOL -> EVM transfers, expect transactionRequest.data to contain base64-encoded Solana transaction data. This is not EVM calldata.
• Use a Solana wallet adapter or the LI.FI SDK to deserialize, sign, and submit Solana transactions. Do not manually rebuild the transaction unless the docs for the exact flow require it.
• Validate token decimals from /tokens or /token; do not assume EVM and Solana versions of a token share decimals or addresses.
• If status is slow, pass the source transaction hash plus fromChain, toChain, and bridge/tool key from the quote.

Execution Patterns