Cross-network swaps from any language: the SODAX Swaps API

A cross-network swap through SODAX needs no SDK, no viem and no wallet library. If your stack can send an HTTP request and sign a transaction, it can swap across the networks SODAX supports. The Swaps API is the same surface the SODAX SDK’s swaps client calls, so a direct integration reaches the same liquidity layer and the same settlement. The shape of every integration is five steps:

Quote the pair.
Build an unsigned transaction. The API returns it with the intent and relay payload already assembled.
Sign and broadcast it wherever your keys live: a custodian, an HSM, a smart wallet, a backend signer.
Submit the broadcast transaction hash.
Poll until the swap is solved or failed.

The API never sees a private key. It hands you bytes to sign and waits for a transaction hash. That split is what makes it a fit for Python services, Go trading bots, Rust backends, exchanges and agents.

The flow on the wire

Base URL: https://api.sodax.com/v1/swaps. All amounts are decimal strings in the token’s smallest unit. The example below swaps USDC for TSLAx (a tokenized Tesla xStock) on Solana, the same pair the public Go demo uses.

0. Find your tokens

curl -s https://api.sodax.com/v1/swaps/tokens/solana

Each entry carries symbol, name, decimals, address and chainKey. GET /tokens returns every supported token grouped by chain key. The chain key (solana, 0xa4b1.arbitrum, 0x2105.base and so on) is how every other endpoint names a network.

1. Quote

curl -s https://api.sodax.com/v1/swaps/quote \
  -H 'content-type: application/json' \
  -d '{
    "tokenSrc": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
    "tokenSrcChainKey": "solana",
    "tokenDst": "XsDoVfqeBukxuZHWhdvWHBhgEHjGNst4MLodqsJHzoB",
    "tokenDstChainKey": "solana",
    "amount": "5000000",
    "quoteType": "exact_input"
  }'
# {"quotedAmount":"1380300"}

quotedAmount is in the destination token’s smallest unit. exact_input is the supported quote type. Apply your slippage tolerance to it to get the minOutputAmount for the next step.

2. Build the unsigned transaction

curl -s https://api.sodax.com/v1/swaps/intents \
  -H 'content-type: application/json' \
  -d '{
    "srcChainKey": "solana",
    "dstChainKey": "solana",
    "inputToken": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
    "outputToken": "XsDoVfqeBukxuZHWhdvWHBhgEHjGNst4MLodqsJHzoB",
    "inputAmount": "5000000",
    "minOutputAmount": "1366497",
    "deadline": "1790835277",
    "allowPartialFill": false,
    "srcAddress": "<your-solana-address>",
    "dstAddress": "<your-solana-address>",
    "solver": "0x0000000000000000000000000000000000000000",
    "data": "0x"
  }'

The response is { tx, intent, relayData }. tx is the unsigned transaction for the source network: { from, to, value, data } on EVM chains, and a chain-specific shape elsewhere (on Solana, tx.data is a base64 transaction with an empty signature slot). GET /deadline?offsetSeconds=600 returns a ready-made deadline if you prefer not to compute one. Note that the quote and intent bodies name the same fields differently (tokenSrc versus inputToken, amount versus inputAmount). To collapse steps 1 and 2 into one call, send the quote with ?includeTxData=true plus srcAddress and dstAddress; the response then includes txData in the same { tx, intent, relayData } shape. For ERC-20 inputs on EVM networks, POST /allowance/check and POST /approve cover the approval step with the same request body as /intents.

3. Sign and broadcast

This is the step that stays on your side. Decode tx, sign it with whatever holds the key, broadcast it to the source network and keep the resulting transaction hash.

4. Submit

curl -s https://api.sodax.com/v1/swaps/submit-tx \
  -H 'content-type: application/json' \
  -d '{
    "txHash": "<source-tx-hash>",
    "srcChainKey": "solana",
    "walletAddress": "<your-solana-address>",
    "intent": { "...": "verbatim from step 2" },
    "relayData": "<relayData.payload from step 2>"
  }'
# {"success":true,"data":{"status":"inserted","message":"..."}}

submit-tx is idempotent on (txHash, srcChainKey), so a retry after a timeout returns "duplicate" instead of a second submission. Back off on 429.

5. Poll

curl -s "https://api.sodax.com/v1/swaps/submit-tx/status?txHash=<source-tx-hash>&srcChainKey=solana"

data.status moves through pending, relaying, relayed, posting_execution and posted_execution, then lands on solved or failed. Only those last two are terminal. Transient relay hiccups stay on an in-flight status, so a failed is real and comes with a userMessage. If the intent is still open on-chain after a failure, build a cancel transaction with POST /intents/cancel to recover the input.

The same flow in Go

The gosodax/swap-api-demo repository runs this exact lifecycle in Go: USDC to TSLAx on Solana, no @sodax/sdk, no TypeScript, no browser. The orchestration in internal/swap/swap.go reads like the list above:

q, err := d.API.Quote(ctx, sodax.QuoteRequest{
    TokenSrc: r.Input.Mint, TokenSrcChainKey: r.SrcChainKey,
    TokenDst: r.Output.Mint, TokenDstChainKey: r.DstChainKey,
    Amount: r.InputAmount, QuoteType: "exact_input",
})
minOut := applySlippage(q.QuotedAmount, r.SlippageBps)

ci, err := d.API.CreateIntent(ctx, sodax.CreateIntentRequest{ /* ...MinOutputAmount: minOut... */ })

txHash, err := d.Sender.SignAndSend(ctx, r.Account, ci.Tx.Data) // the only step that touches the key

err = d.API.SubmitTx(ctx, sodax.SubmitTxRequest{
    TxHash: txHash, SrcChainKey: r.SrcChainKey, WalletAddress: addr,
    Intent: ci.Intent, RelayData: ci.RelayData.Payload,
})

return poll(ctx, d.API, txHash, r.SrcChainKey, logf) // every 3s until solved or failed

Against the live production API, the demo verifies that the quote returns a price, that /intents returns an unsigned Solana transaction, and that the transaction deserializes, re-signs and reaches on-chain simulation. A real fill only needs a funded wallet. One practical detail from the demo: it refreshes the blockhash baked into the unsigned Solana transaction before signing, so sign and send promptly.

Charging a partner fee

Quote, intent, allowance, approve and limit-order bodies accept an optional partnerFee object:

"partnerFee": { "address": "0x<fee-receiver-on-sonic>", "percentage": 10 }

address is the EVM hub address that receives the fee. percentage is in basis points (1 to 100, so 10 is 0.1%), or send a fixed amount in the input token’s smallest unit instead. If both are present, amount wins. There is no default fee: omit the field and no partner fee applies. GET /fees/partner?amount=... returns the computed fee for an input amount.

Include partnerFee on every quote and intent request, with the same value each time. The quote then matches what the intent charges, and your users see one consistent price. submit-tx does not take it, because the fee is already encoded in the intent.

A typed client for TypeScript

On a TypeScript backend, the optional @sodax/swaps-api package wraps these endpoints with one method each (getQuote, createIntent, submitTx, getSubmitTxStatus and the rest). It validates every response at runtime, converts unsigned transactions back to domain types, throws a single SwapsApiError with endpoint and status context, and retries idempotent reads and quotes on transient faults. It depends only on @sodax/types and valibot: no @sodax/sdk, no viem, no wallet providers. All three reach the same SODAX execution and liquidity. Pick by how much you want to own.

	Swaps API	SDK	Swap widget
Language	Anything that speaks HTTP	TypeScript	None, it is an iframe
Signing	Your infrastructure	Wallet providers in the SDK stack	The user’s wallet, inside the widget
Best for	Backends, bots, exchanges, custodial flows, non-JS stacks	TypeScript dapps that want wallet and React layers	Adding swaps to a product page fast

If your stack is TypeScript and you want wallet connection handled, the SDK is the shorter path. If you want a swap on a page today with nothing to maintain, use the swap widget. Everywhere else, the API is the direct route.

Go further

Swagger reference

Every endpoint, request schema and example, live against production.

Swaps API docs

Status fields, failure handling, limit orders and the full endpoint catalog.

Go demo

A complete Solana swap over plain HTTP with local signing.

SODAX API overview

Supported networks, assets and integration paths.

Blog

Cross-network swaps from any language: the SODAX Swaps API

The flow on the wire

0. Find your tokens

1. Quote

2. Build the unsigned transaction

3. Sign and broadcast

4. Submit

5. Poll

The same flow in Go

Charging a partner fee

A typed client for TypeScript

API vs SDK vs widget

Go further

Swagger reference

Swaps API docs

Go demo

SODAX API overview

​The flow on the wire

​0. Find your tokens

​1. Quote

​2. Build the unsigned transaction

​3. Sign and broadcast

​4. Submit

​5. Poll

​The same flow in Go

​Charging a partner fee

​A typed client for TypeScript

​API vs SDK vs widget

​Go further

Swagger reference

Swaps API docs

Go demo

SODAX API overview

The flow on the wire

0. Find your tokens

1. Quote

2. Build the unsigned transaction

3. Sign and broadcast

4. Submit

5. Poll

The same flow in Go

Charging a partner fee

A typed client for TypeScript

API vs SDK vs widget

Go further