> ## Documentation Index > Fetch the complete documentation index at: https://docs.layerswap.io/llms.txt > Use this file to discover all available pages before exploring further. # API quickstart > Move ETH from Ethereum to Arbitrum through the API in four calls: quote, create, deposit, track. ```text theme={null} Base URL: https://api.layerswap.io/api/v2 Auth: X-LS-APIKEY: ``` Read endpoints (`/networks`, `/quote`, `/sources`, `/destinations`) are public — they work without a key. Send the key anyway so the environment and your app attribution are right. **If auth fails:** an *invalid* key returns `403` with `{"error": {"code": "API_KEY_FORBIDDEN", "message": "Api key forbidden"}}`. A *missing* key silently gives you public mainnet access — don't mistake it for a working testnet setup. ```bash theme={null} curl "https://api.layerswap.io/api/v2/limits?source_network=ETHEREUM_MAINNET&source_token=ETH&destination_network=ARBITRUM_MAINNET&destination_token=ETH" \ -H "X-LS-APIKEY: $LS_API_KEY" ``` Networks are identified by canonical ids like `ETHEREUM_MAINNET` — enumerate them with [`GET /networks`](/api-reference/swaps/get-networks), or use [`GET /sources`](/api-reference/swaps/get-sources) / [`GET /destinations`](/api-reference/swaps/get-destinations) to see what's routable from where. **If the route doesn't exist:** `404` — `{"error": {"code": "ROUTE_NOT_FOUND_ERROR", "message": "Route not found"}}`. The pair isn't currently supported; there is no partial success. **If a parameter is malformed** (bad enum value, missing required param): the API returns `400` **with an empty body** — no JSON. Treat empty-body 400s as validation failures and re-check parameter names and casing. ```bash theme={null} curl "https://api.layerswap.io/api/v2/quote?source_network=ETHEREUM_MAINNET&source_token=ETH&destination_network=ARBITRUM_MAINNET&destination_token=ETH&amount=0.1" \ -H "X-LS-APIKEY: $LS_API_KEY" ``` ```json theme={null} { "data": { "quote": { "requested_amount": 0.1, "receive_amount": 0.09999856, "min_receive_amount": 0.09999856, "blockchain_fee": 0.00000043, "service_fee": 0.00000102, "total_fee": 0.00000145, "total_fee_in_usd": 0.002769, "avg_completion_time": "00:00:03.6643572", "path": [{ "provider": "LAYERSWAP", "order": 0 }] }, "refuel": null, "reward": null } } ``` Every successful response is wrapped in `data`. Fee semantics live in [Fees](/concepts/fees); `avg_completion_time` is a .NET-style duration string. The quote response has no expiry field. What rate applies if the user deposits later, and how long a quote should be treated as indicative, is pending a product answer. Until then: do not present `receive_amount` as guaranteed. **If the amount is out of range:** compare against the `/limits` response from step 1 — quotes for amounts outside min/max fail. ```bash theme={null} curl -X POST "https://api.layerswap.io/api/v2/swaps" \ -H "X-LS-APIKEY: $LS_API_KEY" \ -H "Content-Type: application/json" \ -d '{ "source_network": "ETHEREUM_MAINNET", "source_token": "ETH", "destination_network": "ARBITRUM_MAINNET", "destination_token": "ETH", "amount": 0.1, "destination_address": "0xYourUsersAddress", "refund_address": "0xYourSourceNetworkRefundAddress", "reference_id": "your-unique-attempt-id" }' ``` The response contains the swap (`data.swap.id`) and `data.deposit_actions` — the instructions for funding it. Store the id; it's your handle for tracking. When `refund_address` is required (routes involving a swap provider) and what error you get without it is unconfirmed. Recommendation until answered: always supply `refund_address` on the source network. Whether `reference_id` deduplicates retries (idempotency) is unconfirmed — until then, guard against double-creating swaps on your side. Each entry in `deposit_actions` tells you where and how to send the funds — `to_address`, `amount`, `amount_in_base_units`, and for contract interactions `call_data`. For this direct transfer, have the user's wallet send the exact amount to `to_address` on the source network. Other funding methods use the same swap object with different flags: [Depository contract calls](/api/funding/depository) (`use_depository`) and [gasless signatures](/api/funding/gasless) (`use_gasless`). **If the user sends an invalid amount:** inspect `fail_reason`; the swap may enter the [refund flow](/concepts/refunds). **If the user never sends:** the swap moves to `expired` after six hours. See [Swap lifecycle & statuses](/concepts/swap-lifecycle) instead of inferring recovery behavior. ```bash theme={null} curl "https://api.layerswap.io/api/v2/swaps/$SWAP_ID" -H "X-LS-APIKEY: $LS_API_KEY" ``` `data.swap.status` walks the lifecycle: `user_transfer_pending` → deposit detected → `ls_transfer_pending` → `completed`. Terminal failure states are `failed`, `expired`, and `refunded`. The full state machine is in [Swap lifecycle & statuses](/concepts/swap-lifecycle); the separate PascalCase query vocabulary is in [Track swaps](/api/track-swaps). You can also look a swap up by its funding transaction: `GET /swaps/by_transaction_hash/{hash}`. Recommended polling cadence and webhook delivery semantics are unconfirmed. Poll conservatively, back off on failures, and configure [Webhooks](/api/webhooks) in the Partner Dashboard. ## Next steps * Understand what you used: [Routes, quotes & limits](/concepts/routes-quotes-limits) and [Swap lifecycle & statuses](/concepts/swap-lifecycle) * Implement source-network actions: [Fund by transfer](/api/funding/transfer), [Depository](/api/funding/depository), or [Gasless deposits](/api/funding/gasless) * Prepare for launch with the [Production checklist](/resources/production-checklist)