The Swaplume API

Live offers from 9 instant exchanges, and swaps at the best one, for your app or AI agent. Free, no API key, no account.

API reference OpenAPI spec llms.txt

A swap in three calls

1 · Compare every exchange

curl "https://api.swaplume.com/v1/quotes?from=btc&to=eth&amount=0.1"

Every offer, best first. Amounts are what the user receives after all fees.

2 · Create the swap

curl -X POST https://api.swaplume.com/v1/swaps \
  -H "content-type: application/json" \
  -d '{"from": "btc", "to": "eth", "amount": "0.1", "address": "<ETH address>"}'

Without a provider, Swaplume takes the best rate at that moment and falls back to the next one if it fails. The response has the deposit_address the user sends to, and plain-English instructions.

3 · Follow it

curl https://api.swaplume.com/v1/swaps/$SWAP_ID

$SWAP_ID is the id step 2 returned. Read it again every poll_after seconds until is_final is true. Statuses go waiting, confirming, exchanging, sending, finished.

The user then sends their coins to the deposit address from their own wallet. Swaplume never holds funds: the exchange receives the deposit and pays out to the user's address.

Connect an AI agent

The same features are an MCP server at https://api.swaplume.com/mcp, over streamable HTTP with no auth.

Claude Code

claude mcp add --transport http swaplume https://api.swaplume.com/mcp

Claude Desktop and claude.ai: Settings, Connectors, Add custom connector, with the URL above.
Cursor, VS Code, Windsurf and others: add a remote (HTTP) MCP server with the same URL.

Tools: get_quotes, validate_address, create_swap, get_swap, list_currencies, list_providers.

Endpoints

GET /v1/quotes: Every exchange's offer for a swap, best first, and why the others can't do it.
GET /v1/quotes/stream: The same comparison as Server-Sent Events, updated as each exchange answers.
POST /v1/swaps: Create a swap. Returns the deposit address, memo when one is needed, and instructions.
GET /v1/swaps/{id}: Live status, the payout transaction once sent, and what to do next.
POST /v1/validate-address: Check an address for an asset before creating the swap.
GET /v1/currencies: Supported assets and networks, with filters.
GET /v1/providers: The exchanges compared: KYC level, email and refund address support.
GET /v1/prices: BTC, ETH, SOL, XMR, LTC, XRP and TON in USDT at the best exchange. /v1/prices.png draws them.

Good to know

Assets are a ticker plus a network: btc, usdt:trx, usdc:sol. Names like tron, erc20 or bep20 work as networks.
Amounts are decimal strings. A floating rate is an estimate; rate_type=fixed locks the amount for a short time, until the quote's expires_at (pass its rate_id when creating).
To receive an exact amount, pass amount_to instead of amount, at a fixed rate: each quote's amount_from is what to send, least first.
Each quote says how likely its exchange is to ask the user for ID (kyc), whether it needs the user's email (email_required) and whether it takes a refund address (refund_address_supported).
Errors are JSON: {"error": {"code", "message", "details"}}, with messages you can show to users.
Limits: 60 requests a minute and 20 new swaps an hour, per IP. Need more? Tell us.
It's free: the exchanges pay Swaplume a commission on swaps, already included in the quotes.