Q1

Use Q1 when you need Carbium's current executable quote flow, not the older v1 quote and swap request family.

Q1 is the documented GET /api/v2/quote surface for:

• live route and output calculation
• route-plan inspection before signing
• an executable txn payload when user_account is included

Part of the Carbium Solana infrastructure stack.

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What this page owns

This page owns the current v2 quote flow only:

Surface	What it does
GET https://api.carbium.io/api/v2/quote	Returns quote data for a swap request and can include a base64 transaction payload

Use other pages when the question changes:

• use Get your API key for portal setup and key creation
• use Executing Swaps for sign -> submit -> confirm
• use Swap API Request Families when you are comparing Q1 with older v1 quote or swap paths
• use Swap API Errors Reference for auth, route, or missing-txn failures

If you are maintaining the older parameter family with fromMint, toMint, and amount, stay on the older v1 reference pages instead of mixing request styles.

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Request shape

Method: GET

URL:

https://api.carbium.io/api/v2/quote

Header:

X-API-KEY: YOUR_API_KEY

Parameter	Required	Meaning
src_mint	Yes	Input token mint
dst_mint	Yes	Output token mint
amount_in	Yes	Raw input amount in smallest units
slippage_bps	Yes	Slippage tolerance in basis points
user_account	No	Wallet address for an executable transaction response

📘 Q1 uses src_mint, dst_mint, amount_in, and slippage_bps. Do not mix these with fromMint, toMint, amount, or slippage from the older v1 surfaces.

---

Minimal quote request

Use this when you only need pricing and route data:

curl --request GET \
  --url 'https://api.carbium.io/api/v2/quote?src_mint=So11111111111111111111111111111111111111112&dst_mint=EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v&amount_in=1000000&slippage_bps=50' \
  --header 'X-API-KEY: YOUR_API_KEY'

Use this when you need an executable transaction back:

curl --request GET \
  --url 'https://api.carbium.io/api/v2/quote?src_mint=So11111111111111111111111111111111111111112&dst_mint=EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v&amount_in=1000000&slippage_bps=50&user_account=YOUR_WALLET' \
  --header 'X-API-KEY: YOUR_API_KEY'

The important difference is user_account:

• without it, Q1 can behave like a quote-only surface
• with it, the response can include txn, a base64-encoded transaction payload ready for deserialization and signing

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Response fields that matter

Typical Q1 responses include fields like these:

Field	Why it matters
srcAmountIn	Confirms the raw input amount used for routing
destAmountOut	Expected output amount
destAmountOutMin	Minimum output after slippage
priceImpactPct	Quick price-impact sanity check
routePlan	Route composition before signing
txn	Base64 transaction payload when user_account is present

Example response shape:

{
  "srcAmountIn": "1000000",
  "destAmountOut": "1257091",
  "destAmountOutMin": "1257091",
  "slippage": "50",
  "priceImpactPct": "0",
  "routePlan": [
    {
      "swap": "Raydium",
      "percent": 100
    }
  ],
  "txn": "AQAAAA..."
}

Treat txn as the handoff into your signing and submission flow, not as proof that the swap already landed on-chain.

---

Typical integration flow

Use this order for most new integrations:

1. request a quote from Q1
2. inspect output amount, minimum amount, and route plan
3. include user_account when you need an executable transaction
4. deserialize and sign the returned txn
5. submit and confirm through Carbium RPC

const url = new URL("https://api.carbium.io/api/v2/quote");
url.searchParams.set("src_mint", inputMint);
url.searchParams.set("dst_mint", outputMint);
url.searchParams.set("amount_in", amountIn);
url.searchParams.set("slippage_bps", "50");
url.searchParams.set("user_account", wallet.publicKey.toBase58());

const quote = await fetch(url, {
  headers: { "X-API-KEY": process.env.CARBIUM_API_KEY! },
}).then((r) => r.json());

if (!quote.txn) {
  throw new Error("Missing executable transaction in Q1 response");
}

This page stops at the quote-build boundary. Move to Executing Swaps for the signing and RPC submission stage.

---

Validation checklist before production

• send X-API-KEY on every request
• use src_mint, dst_mint, amount_in, and slippage_bps together
• send amounts in smallest units
• require user_account if your integration expects txn
• fail fast if the quote returns no route or no executable payload

🔶 Use Q1 for the current executable quote flow, then move into Executing Swaps once the quote response looks correct. For platform setup and product access, start at carbium.io.