Clawallex#

Pay for anything with USDC. Clawallex converts your stablecoin balance into virtual cards that work at any online checkout.

Features#

• Flash Cards — one-time use virtual cards for single payments
• Stream Cards — reloadable cards for subscriptions, top up with refill
• Mode A — pay from your USDC wallet balance
• Mode B — on-chain x402 payment for callers with self-custody wallets (agent or user) — signing is performed by the caller
• Zero dependencies — Python 3.9+ stdlib only

Quick Start#

1. Set Up Account#

New user — browser signup (recommended):

bash

python3 {baseDir}/scripts/clawallex.py signup

Returns a URL and token. Show the URL to the user, ask them to open it and click Authorize. The command polls automatically. If polling fails, retry with the token:

bash

python3 {baseDir}/scripts/clawallex.py signup-check --token <token>

Existing user — connect with API keys:

Get your API Key and Secret at app.clawallex.com/dashboard/settings, then run:

bash

python3 {baseDir}/scripts/clawallex.py setup --action connect --api-key YOUR_KEY --api-secret YOUR_SECRET

2. Verify#

bash

python3 {baseDir}/scripts/clawallex.py wallet          # check balance
python3 {baseDir}/scripts/clawallex.py cards            # list cards

Hard Rules#

1. Setup first — Run setup --action status before any payment. If not configured: use signup for new accounts, or setup --action connect if the user already has API keys.
2. Check balance first — Run wallet before pay or subscribe to verify sufficient funds (Mode A only).
3. Never expose card secrets — Decrypted PAN/CVV are STRICTLY for filling checkout forms. NEVER display to the user. Show only masked_pan from card-details.
4. Confirm before paying — Echo amount and description back to user before creating a card.
5. One command at a time — Run each command, check output, then proceed.

Typical Flows#

Payment Flow (Mode A — Wallet Balance)#

text

1. setup --action status                                    → check config
2. wallet                                                   → check balance
3. pay --amount 50 --description "OpenAI"                   → create flash card
4. card-details --card-id <ID from step 3>                  → get encrypted card data
5. Decrypt PAN/CVV (HKDF + AES-256-GCM)                    → use ONLY for checkout form

Subscription Flow#

text

1. wallet                                                   → check balance
2. subscribe --amount 100 --description "AWS billing"       → create stream card
3. card-details --card-id <ID from step 2>                  → get card for sign-up form
4. refill --card-id <ID> --amount 50                        → top up when balance is low

Command Reference#

All commands:

text

python3 {baseDir}/scripts/clawallex.py <command> [args]

Setup & Identity#

User IntentCommandQuick signup — browser-based new account creation (recommended for first-time setup)signupCheck signup result with existing tokensignup-check --token TOKENConnect accountsetup --action connect --api-key KEY --api-secret SECRETCheck config statussetup --action statusGet sign-up linksetup --action registerCheck API Key bindingwhoamiBind client_idbootstrap or bootstrap --preferred-client-id MY_ID

Payments#

User IntentCommandPay for somethingpay --amount N --description "X"Pay with custom expirypay --amount N --description "X" --ttl SECONDS — flash card only; default 86400 (24 h)Start subscriptionsubscribe --amount N --description "X"Top up cardrefill --card-id CID --amount N

Wallet & Cards#

User IntentCommandCheck balancewalletDeposit fundsrecharge-addresses --wallet-id WIDList cardscards — returns mode_code (100=Mode A, 200=Mode B) to determine refill pathCheck card balancecard-balance --card-id CIDBatch check balancesbatch-balances --card-ids CID1,CID2 — multiple cards in one callUpdate card controlsupdate-card --card-id CID --client-request-id UUID [--tx-limit] [--allowed-mcc] [--blocked-mcc]Get card detailscard-details --card-id CID — returns masked_pan, expiry, balance, first_name, last_name, tx_limit, allowed_mcc, blocked_mcc, encrypted PAN/CVVView transactionstransactions

Advanced (x402 On-Chain)#

User IntentCommandGet x402 payee addressx402-address --chain ETH --token USDC — MUST call before Mode B Refill

Setup Flow#

When the user wants to use Clawallex for the first time:

1. Run setup --action status to check current configuration.

2. If not configured, ask: "Do you have a Clawallex account?"

   • Yes, have API keys: Ask for API Key and Secret, then run: text

     setup --action connect --api-key KEY --api-secret SECRET
     
     

     This automatically verifies credentials, binds client_id, and saves locally.

   • No account yet: Run the browser signup flow: text

     signup
     
     

     This generates a URL and a token — show the URL to the user and ask them to open it and click Authorize. The command polls automatically. If polling fails or times out, use the token to retry manually: text

     signup-check --token <token from signup output>
     
     

3. Verify with wallet to confirm connection works.

Signup result statuses — all returned as success: true:

• pending — user hasn't authorized yet, call signup-check again
• ok — credentials saved, ready to use
• cancelled — user cancelled, ask if they want to try again
• already_exists — account already has API keys, switch to setup --action connect

Mode B Flow (x402 On-Chain, Two-Stage)#

Mode B is for callers with self-custody wallets (agent or user) (DeFi bots, autonomous purchasing agents). The agent signs on-chain transactions using its own signing system — no human intervention needed.

Stage 1 — Quote:

text

pay --amount 200 --description "GPU rental" --mode-code 200 --chain-code ETH --token-code USDC

The 402 response is EXPECTED — it is a quote, NOT an error. Returns:

• client_request_id, payee_address, asset_address, x402_reference_id
• final_card_amount, issue_fee_amount, fx_fee_amount, fee_amount, payable_amount

Fee structure:

• flash card: fee_amount = issue_fee_amount + fx_fee_amount
• stream card: fee_amount = issue_fee_amount + monthly_fee_amount + fx_fee_amount

Agent signs — construct and sign an EIP-3009 transferWithAuthorization using your own wallet/signing library and the quote details. Only the resulting signature and your wallet address are needed for Stage 2. EIP-3009 enables gasless USDC transfers via off-chain signatures. The authorization fields map to:

• from: your wallet address (the payer)
• to: payee_address from Stage 1 (system receiving address)
• value: maxAmountRequired (payable_amount in token minimal units, USDC = 6 decimals)
• validAfter / validBefore: unix timestamps (seconds) defining the signature validity window
• nonce: random 32-byte hex, must be unique per authorization

Stage 2 — Settle (MUST use same client_request_id):

text

pay --amount 200 --description "GPU rental" \
  --mode-code 200 \
  --client-request-id "uuid-from-stage-1" \
  --x402-version 1 \
  --payment-payload '{
    "scheme": "exact",
    "network": "ETH",
    "payload": {
      "signature": "0x<agent EIP-3009 signature>",
      "authorization": {
        "from": "0x<agent wallet address>",
        "to": "<payee_address from stage 1>",
        "value": "<maxAmountRequired, e.g. 207590000>",
        "validAfter": "<unix timestamp seconds>",
        "validBefore": "<unix timestamp seconds>",
        "nonce": "0x<random 32-byte hex>"
      }
    }
  }' \
  --payment-requirements '{
    "scheme": "exact",
    "network": "ETH",
    "asset": "<asset_address from stage 1>",
    "payTo": "<payee_address from stage 1>",
    "maxAmountRequired": "<payable_amount × 10^6, e.g. 207590000>",
    "extra": {
      "referenceId": "<x402_reference_id from stage 1>"
    }
  }' \
  --extra '{"card_amount": "200.0000", "paid_amount": "<payable_amount, e.g. 207.5900>"}'

Stage 2 constraints:

• --client-request-id MUST be identical to Stage 1 — a different value creates a NEW order
• payment_requirements.payTo MUST equal payee_address from Stage 1
• payment_requirements.asset MUST equal asset_address from Stage 1
• payment_requirements.maxAmountRequired MUST equal payable_amount × 10^decimals (USDC = 6 decimals)
• payment_requirements.extra.referenceId MUST equal x402_reference_id from Stage 1
• extra.card_amount MUST equal the --amount
• extra.paid_amount MUST equal payable_amount from Stage 1 ( amount + fee_amount)
• payment_payload.network MUST equal payment_requirements.network
• payload.authorization.to MUST equal payment_requirements.payTo
• payload.authorization.value MUST equal payment_requirements.maxAmountRequired
• Server will force-inject extra.mode=STANDARD — any client-provided value is ignored
• If settle is rejected, order stays pending_payment — fix params and retry with same client_request_id

Mode B Refill Flow (no 402 challenge)#

Mode B refill goes directly to x402 settle — no 402 challenge stage. Caller signs the EIP-3009 authorization independently using their own wallet/signing library; only the resulting signature and wallet address are submitted. Must call x402-address first to get payee_address.

text

1. x402-address --chain ETH --token USDC                    → get payee_address
2. refill --card-id c_123 --amount 50 \
     --x402-reference-id "<unique reference id>" \
     --x402-version 1 \
     --payment-payload '{
       "scheme": "exact",
       "network": "ETH",
       "payload": {
         "signature": "0x<EIP-3009 signature>",
         "authorization": {
           "from": "0x<agent wallet>",
           "to": "<payee_address from step 1>",
           "value": "<amount × 10^6>",
           "validAfter": "<unix seconds>",
           "validBefore": "<unix seconds>",
           "nonce": "0x<random 32-byte hex>"
         }
       }
     }' \
     --payment-requirements '{
       "scheme": "exact",
       "network": "ETH",
       "asset": "<asset contract address>",
       "payTo": "<payee_address from step 1>",
       "maxAmountRequired": "<amount × 10^6>",
       "extra": { "referenceId": "<x402_reference_id>" }
     }'

Mode B refill idempotency key is x402_reference_id (not client_request_id). Check cards mode_code to determine which refill path the card uses.

How to Talk to the User#

During setup#

• "I need your Clawallex API Key and Secret to get started. You can find them at app.clawallex.com/dashboard/settings."
• If no account: "No problem — I can get you a sign-up link."
• After connect: "You're all set! Want to check your balance?"

During payments#

• Always confirm: "I'll create a $50 card for OpenAI API credits, deducted from your wallet balance. Go ahead?"
• After card creation: "Card created! Let me get the card details for checkout."
• Never show PAN/CVV in conversation. Show only masked_pan if asked.

On errors#

• Don't blame the user. Be actionable: "Your wallet balance is $20 but this needs $50. You can deposit more USDC or try a smaller amount."
• 402 response (Mode B): This is expected — explain it's the first step of a two-stage payment, not an error.

Decrypting Card Sensitive Data#

card-details returns encrypted_sensitive_data with encrypted PAN/CVV:

1. Derive key: HKDF-SHA256(ikm=api_secret, salt=empty, info="clawallex/card-sensitive-data/v1", length=32)
2. Decode: nonce = base64_decode(nonce), raw = base64_decode(ciphertext)
3. Split: encrypted_data = raw[:-16], auth_tag = raw[-16:]
4. Decrypt: AES-256-GCM(key, nonce, encrypted_data, auth_tag) → JSON
5. Result: {"pan": "4111111111111111", "cvv": "123"}

Error Recovery#

ErrorCauseAction"not configured"No credentials savedRun setup --action connect with valid credentials"Invalid credentials"Wrong API Key/SecretCheck at app.clawallex.com/dashboard/settingsInsufficient balanceWallet balance too lowRun recharge-addresses for deposit info, or use Mode B402 responseMode B Stage 1 (expected)This is the quote — proceed to Stage 2 with same client_request_idSettle rejected (Mode B)Invalid x402 paramsOrder stays pending_payment — fix params and retry with same client_request_idCard not foundWrong card_idRun cards to list valid card IDsDecryption failedBad data or apiSecret changedRe-fetch via card-details, verify credentials

Output Format#

All commands return JSON:

• success: true → data in data field, next steps in _hint
• success: false → error message in error field

Key Concepts#

• Flash card: Created by pay. Single-use, auto-destroyed after one transaction. Cannot be refilled.
• Stream card: Created by subscribe. Reloadable, top up with refill.
• Wallet: Your USDC balance. Funds all Mode A operations.
• Mode A (mode_code=100): Wallet balance deduction (default).
• Mode B (mode_code=200): x402 on-chain USDC payment for callers with self-custody wallets (agent or user). Two-stage (quote → sign → settle). Agent signs EIP-3009 independently; only the signature and wallet address are passed to Stage 2.
• client_id: The agent's stable identity, separate from the API Key. An agent can have multiple API Keys (for rotation/revocation), but client_id never changes. Cards and transactions are isolated per client_id. When switching to a new API Key, keep using the same client_id — the new key auto-binds on first request. Once bound, it cannot be changed (TOFU). Stored locally at ~/.clawallex/credentials.json.