Buy credits from a wallet

#1. Open a purchase

POST/v1/credits/purchase

curl https://inference.dagon.so/v1/credits/purchase \
  -H "Authorization: Bearer $DAGON_KEY" \
  -H "Content-Type: application/json" \
  -d '{"amount_usd": 20, "payer_wallet": "<base58 address>", "chain": "solana"}'

$5 to $1,000, whole cents. chain must be solana. The answer: purchase_id, amount_total, currency (usdc), unsigned_transaction (base64), blockhash, last_valid_block_height, fee_sponsored, expires_at and confirm_url.

#2. Sign

Deserialize unsigned_transaction (for example VersionedTransaction.deserialize in @solana/web3.js) and sign it with the wallet as returned, without rebuilding it. Its blockhash expires about a minute after step 1; if it does, open a new purchase.

When fee_sponsored is true, do not send it: its fee payer is the payment service's, which adds its signature and sends the transaction at confirm. The wallet then needs USDC and no SOL. When false, the wallet is the fee payer: send the transaction yourself (it pays the network fee in SOL), then confirm with its signature.

#3. Confirm

POST/v1/credits/purchase/confirm

curl https://inference.dagon.so/v1/credits/purchase/confirm \
  -H "Authorization: Bearer $DAGON_KEY" \
  -H "Content-Type: application/json" \
  -d '{"purchase_id": "<purchase_id>", "signed_transaction": "<base64 wallet-signed transaction>"}'

signed_transaction is the base64 wallet-signed transaction, required when fee_sponsored is true: the payment service checks it is exactly the prepared payment, adds the fee payer's signature and sends it. When false, send signature instead, the base58 signature of the transaction you sent.

200 {"status": "credited", "credited_usd", "balance"} once the payment is final (the call can take about 45 seconds). 202 {"status": "pending"} means call again, with the same body, after Retry-After. GET /v1/credits/purchase/:id reports open, credited, expired, refused or pending.

Copy-and-paste TypeScript and Python scripts: buy credits from an agent wallet.

#Errors