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Intents API — Signing

Part of the Intents API guide.

Multi-chain signing keys​

Instead of manually storing a raw private key in a vault, you can provision HSM-backed signing keys directly on the agent. 1claw generates the keypair inside the HSM and stores the private key in the org's __agent-keys vault — the key never leaves hardware.

Supported chains​

ChainCurveAddress format
Ethereumsecp256k10x (EIP-55 checksum)
Bitcoinsecp256k1P2WPKH bech32 (bc1q… / tb1q…) — via rust-bitcoin
SolanaEd25519Base58 — via solana-sdk
XRPEd25519Base58Check (r…)
CardanoEd25519Bech32 enterprise (addr1…)
Tronsecp256k1Base58Check (T…)

Provisioning a key​

curl -X POST "https://api.1claw.xyz/v1/agents/$AGENT_ID/signing-keys" \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{ "chain": "ethereum" }'

The response includes the public_key, derived address, curve, and key_version. The private key is stored in the HSM-backed __agent-keys vault.

Key lifecycle​

OperationEndpointSDK
ProvisionPOST /v1/agents/{id}/signing-keysclient.signingKeys.create(agentId, { chain })
ListGET /v1/agents/{id}/signing-keysclient.signingKeys.list(agentId)
RotatePOST /v1/agents/{id}/signing-keys/{chain}/rotateclient.signingKeys.rotate(agentId, chain)
DeactivateDELETE /v1/agents/{id}/signing-keys/{chain}client.signingKeys.deactivate(agentId, chain)
ExportPOST /v1/agents/{id}/signing-keys/{chain}/exportclient.signingKeys.export(agentId, chain, { password })

Only human users can provision, rotate, and export keys — agents get 403. Export requires password re-authentication via the X-Auth-Confirm header and is audit-logged as signing_key.export. Failed re-auth increments failed_login_attempts and can trigger account lockout. Keys for non-EVM chains (Bitcoin, Solana, XRP, Cardano, Tron) support both address derivation and on-chain transaction signing + broadcast — see Non-EVM transaction signing below.

Platform API auto-provisioning

If you're using the Platform API, signing keys can be auto-provisioned during bootstrap by including a signing_keys array in your template spec — no separate API call needed.

Non-EVM transaction signing​

The Intents API signs and broadcasts native transactions for Bitcoin, Solana, XRP, Cardano, and Tron in addition to EVM chains. The same endpoints (POST /v1/agents/:id/transactions for sign + broadcast, POST /v1/agents/:id/transactions/sign for sign-only) dispatch by chain family — you only change the chain and provide chain-appropriate fields. Signing happens in the HSM (or the Shroud TEE); the private key never leaves hardware.

Bitcoin signing uses the official rust-bitcoin crate (v0.32) with full support for P2PKH, P2SH, P2WPKH, P2WSH, and P2TR (Taproot) recipient addresses. Solana signing uses the official solana-sdk crate (v4) with native PDA derivation and SPL token transfer support. XRP uses xrpl-rust for 30+ transaction types.

1claw fetches the chain-specific data it needs automatically (UTXOs and fee rate for Bitcoin, latest blockhash for Solana, account sequence for XRP, protocol parameters and UTXOs for Cardano, the reference block for Tron), signs, and (unless you use the sign-only endpoint) broadcasts via the chain's RPC.

Value units​

value is always the human-readable major unit as a decimal string (e.g. "0.5" for 0.5 BTC). 1claw converts to base units internally:

ChainBase unitDecimalsAddress format
Bitcoinsatoshi8bech32 P2WPKH (bc1q…)
Solanalamport9Base58
XRPdrop6Base58Check (r…)
Cardanolovelace6Bech32 enterprise (addr1…)
Tronsun6Base58Check (T…)

Chain-specific request fields​

All fields are optional and ignored on chains where they don't apply:

FieldTypeChainPurpose
destination_tagnumberXRPDestination tag for exchange deposits
memostringXRP, SolanaOptional memo (planned; currently accepted but not applied — use Memos inside xrpl_tx_json for XRP)
fee_rate_sat_per_vbytenumberBitcoinOverride the fetched fee rate
fee_limit_sunnumberTronTRC-20 energy fee limit (default: 100,000,000 = 100 TRX)
token_mintstringSolana (SPL), Tron (TRC-20)Token mint / contract address
token_decimalsnumberSolana, TronToken decimals (default 6)
ttlnumberCardanoTime-to-live (absolute slot; default: current slot + 7200)
xrpl_tx_jsonobjectXRPFull XRPL transaction JSON for 30+ transaction types (e.g. TrustSet, OfferCreate, NFTokenMint). Overrides to/value/destination_tag when present.

For a token transfer, set token_mint (and token_decimals); omit it for a native transfer.

Supported networks & testnets​

All non-EVM chains support both mainnet and testnet signing. Use the chain field to select the network:

ChainMainnet chainTestnet chainTestnet explorerFaucet
Bitcoinbitcoinbitcoin-testnet, bitcoin-signetmempool.space/signetfaucet.coinbin.org (signet, no captcha, 0.001–0.09 sBTC), signetfaucet.com (captcha)
Solanasolanasolana-devnet, solana-testnetexplorer.solana.com/?cluster=devnetfaucet.solana.com (GitHub login), solana airdrop <SOL> <address> --url devnet
XRPxrpxrp-testnettestnet.xrpl.orgxrpl.org/resources/dev-tools/xrp-faucets
Cardanocardanocardano-preprod, cardano-previewexplorer.cardano.org/preprodfaucet.preprod.world.dev.cardano.org (web or API)
Trontrontron-shasta, tron-nileshasta.tronscan.orgshasta.tronex.io (2,000 TRX + 1,000 USDT)
Testnet address formats

Bitcoin testnet/signet addresses use the tb1q… prefix (derived from the same key as mainnet bc1q…). Cardano preprod addresses use addr_test1… (derived from the same key as mainnet addr1…). Solana, XRP, and Tron use the same address format on all networks.

External API dependencies​

ChainExternal serviceRequired config
Bitcoinmempool.spaceNone (public API)
SolanaSolana JSON-RPCNone (public endpoints: api.devnet.solana.com, api.mainnet-beta.solana.com)
XRPXRPL HTTP JSON-RPCNone (public: xrplcluster.com, s.altnet.rippletest.net:51234)
CardanoBlockfrostBLOCKFROST_PROJECT_ID (generic fallback), or per-network: BLOCKFROST_PROJECT_ID_PREPROD, BLOCKFROST_PROJECT_ID_PREVIEW, BLOCKFROST_PROJECT_ID_MAINNET. Also accepts BLOCKFROST_API_KEY as an alias. Free tier: 50k req/day.
TronTronGridNone (public API: api.trongrid.io, api.shasta.trongrid.io)

Cardano Preprod faucet (API)​

The Cardano preprod faucet supports programmatic requests (api key is optional):

curl -X POST "https://faucet.preprod.world.dev.cardano.org/send-money/<YOUR_ADDR_TEST1_ADDRESS>?api_key=ooseiteiquo7Wie9oochooyiequi4ooc"

Rate limit: one request per address per 24 hours. The default API key above is public; you can also submit without one.

Example — native transfers​

# Bitcoin (testnet): send 0.001 BTC
curl -X POST "https://api.1claw.xyz/v1/agents/$AGENT_ID/transactions" \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "chain": "bitcoin-testnet",
    "to": "tb1q...",
    "value": "0.001"
  }'

# Solana (devnet): send 0.25 SOL
curl -X POST "https://api.1claw.xyz/v1/agents/$AGENT_ID/transactions" \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{ "chain": "solana-devnet", "to": "9xQ...", "value": "0.25" }'

# XRP (testnet): send 10 XRP with a destination tag
curl -X POST "https://api.1claw.xyz/v1/agents/$AGENT_ID/transactions" \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{ "chain": "xrp-testnet", "to": "rPT1...", "value": "10", "destination_tag": 12345 }'

The response shape matches EVM: { tx_hash, signed_tx, from, to, value_wei, status }. For non-EVM chains, the value_wei field contains the chain-native base unit (satoshis for Bitcoin, lamports for Solana, drops for XRP, lovelace for Cardano, sun for Tron), signed_tx contains the signed payload (hex or base64 depending on the chain), and tx_hash is the chain-native transaction id (reversed-hex txid for Bitcoin, base58 signature for Solana, uppercase hex for XRP, blake2b-256 hex for Cardano, SHA-256 txID hex for Tron). For sign-only responses, chain_id and nonce are 0 for non-EVM chains.

Tenderly simulation is EVM-only

simulate_first and the /simulate endpoints only apply to EVM chains. For non-EVM chains they are a no-op — use the sign-only endpoint if you want to inspect the signed transaction before broadcasting it yourself.

Unified sign endpoint​

The unified POST /v1/agents/{id}/sign endpoint supports four intent types: EIP-191 message signing (personal_sign), EIP-712 typed data signing (typed_data), raw digest signing (eip712_digest / digest), and transaction signing across all EIP-2718 types.

EIP-191 personal_sign​

Sign an arbitrary human-readable message. Requires message_signing_enabled: true on the agent.

curl -X POST "https://api.1claw.xyz/v1/agents/$AGENT_ID/sign" \
  -H "Authorization: Bearer $AGENT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "intent_type": "personal_sign",
    "chain": "ethereum",
    "message": "Hello from my agent!"
  }'

EIP-712 typed data​

Sign structured typed data (e.g. ERC-20 Permit, gasless approvals). The agent's eip712_domain_allowlist must include the verifyingContract, or eip712_default_policy must be "allow".

curl -X POST "https://api.1claw.xyz/v1/agents/$AGENT_ID/sign" \
  -H "Authorization: Bearer $AGENT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "intent_type": "typed_data",
    "chain": "ethereum",
    "typed_data": {
      "types": { "Permit": [{"name":"owner","type":"address"},{"name":"spender","type":"address"},{"name":"value","type":"uint256"},{"name":"nonce","type":"uint256"},{"name":"deadline","type":"uint256"}] },
      "primaryType": "Permit",
      "domain": { "name": "USD Coin", "version": "2", "chainId": 1, "verifyingContract": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48" },
      "message": { "owner": "0x...", "spender": "0x...", "value": "1000000", "nonce": "0", "deadline": "1735689600" }
    }
  }'

Raw digest signing (ERC-1271 / ERC-7739)​

Some protocols compute a canonical EIP-712 digest client-side — notably ERC-1271 / ERC-7739 nested TypedDataSign payloads used by smart-contract accounts (e.g. Polymarket CLOB orders). For these, re-deriving the hash server-side from typed_data can diverge from the verifier's expected hash and cause the signature to be rejected. The eip712_digest intent signs a pre-computed 32-byte digest directly, returning a 65-byte r‖s‖v signature that recovers to the agent's EOA.

Blind signing

eip712_digest is blind signing: 1Claw cannot inspect what the digest authorizes, so transaction guardrails are bypassed. It is gated behind the per-agent raw_signing_enabled flag (off by default — a human must enable it; agents cannot self-enable), and every use is audit-logged as signing_key.raw_digest_sign. Only enable it for agents that genuinely need ERC-1271/ERC-7739 flows.

curl -X POST "https://api.1claw.xyz/v1/agents/$AGENT_ID/sign" \
  -H "Authorization: Bearer $AGENT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "intent_type": "eip712_digest",
    "chain": "ethereum",
    "hash": "0x59c6995e998f97a5a0044966f0945389dc9e86dae88c7a8412f4603b6b78690d"
  }'
const { data } = await client.agents.sign(agentId, {
  intent_type: "eip712_digest",
  chain: "ethereum",
  hash: "0x59c6...690d", // client-computed canonical 32-byte digest
});
console.log(data.signature, data.from);

Transaction types (EIP-2718)​

The unified sign endpoint supports all EIP-2718 envelope types via the tx_type field:

tx_typeNameKey fields
0Legacy (EIP-155)gas_price
1EIP-2930 (access list)gas_price, access_list
2EIP-1559max_fee_per_gas, max_priority_fee_per_gas
3EIP-4844 (blob)max_fee_per_blob_gas, blob_versioned_hashes
4EIP-7702authorization_list
const { data } = await client.agents.sign(agentId, {
  intent_type: "transaction",
  chain: "sepolia",
  tx_type: 2,
  to: "0xRecipient",
  value: "0",
  max_fee_per_gas: "30000000000",
  max_priority_fee_per_gas: "2000000000",
  gas_limit: 21000,
});

Message signing guardrails​

FieldTypeDescription
message_signing_enabledbooleanMust be true for EIP-191 personal_sign (default: false).
eip712_default_policy"deny" | "allow"Default policy for EIP-712 domains not in the allowlist (default: "deny").
eip712_domain_allowlistJSON[]List of allowed domains, e.g. [{"verifying_contract": "0xA0b..."}]. Known dangerous types (Permit, Permit2) always require explicit allowlisting.
raw_signing_enabledbooleanMust be true for the eip712_digest (raw/blind digest) intent (default: false). Human-set only; agents cannot enable it.

MCP tools​

The MCP server provides transaction tools for the full lifecycle:

simulate_transaction — simulate without signing:

Tool: simulate_transaction
Args:
  chain: "base"
  to: "0xRecipientAddress"
  value: "0.5"
  signing_key_path: "wallets/hot-wallet"

submit_transaction — sign and broadcast (simulation on by default):

Tool: submit_transaction
Args:
  chain: "base"
  to: "0xRecipientAddress"
  value: "0.5"
  signing_key_path: "wallets/hot-wallet"
  simulate_first: true

sign_transaction — sign only, no broadcast (for BYORPC):

Tool: sign_transaction
Args:
  chain: "base"
  to: "0xRecipientAddress"
  value: "0.5"
  signing_key_path: "wallets/hot-wallet"
  simulate_first: true

list_transactions — list recent transactions:

Tool: list_transactions
Args:
  include_signed_tx: false

get_transaction — get details of a specific transaction:

Tool: get_transaction
Args:
  transaction_id: "uuid-of-transaction"
  include_signed_tx: false

provision_signing_key — provision an HSM-backed signing key for a chain:

Tool: provision_signing_key
Args:
  chain: "ethereum"

list_signing_keys — list all signing keys for the current agent:

Tool: list_signing_keys

sign_message — sign an EIP-191 personal message:

Tool: sign_message
Args:
  message: "Hello from my agent"
  chain: "ethereum"

sign_typed_data — sign EIP-712 typed structured data:

Tool: sign_typed_data
Args:
  chain: "ethereum"
  typed_data: { types: {...}, primaryType: "Permit", domain: {...}, message: {...} }

sign_digest — sign a client-computed 32-byte digest directly (raw/blind signing; requires raw_signing_enabled). For ERC-1271 / ERC-7739 nested EIP-712 flows (e.g. Polymarket):

Tool: sign_digest
Args:
  chain: "ethereum"
  hash: "0x59c6...690d"   // canonical 32-byte digest computed client-side

Supported chains​

The proxy can broadcast transactions to any chain in the registry. All mainnet chains below are configured with dedicated dRPC endpoints for reliable transaction delivery.

Querying chains via API

You can always fetch the live list with GET /v1/chains. The response includes chain_id, rpc_url, explorer_url, and native_currency for every chain.

Mainnet chains (29)​

ChainChain IDNative tokenExplorer
Ethereum1ETHetherscan.io
Optimism10ETHoptimistic.etherscan.io
Cronos25CROcronoscan.com
BNB Smart Chain56BNBbscscan.com
Gnosis100xDAIgnosisscan.io
Polygon137POLpolygonscan.com
Sonic146Ssonicscan.org
Fantom250FTMftmscan.com
zkSync Era324ETHexplorer.zksync.io
World Chain480ETHworldscan.org
Metis1088METISandromeda-explorer.metis.io
Polygon zkEVM1101ETHzkevm.polygonscan.com
Moonbeam1284GLMRmoonscan.io
Sei1329SEIseitrace.com
Mantle5000MNTmantlescan.xyz
Kaia8217KAIAkaiascan.io
Base8453ETHbasescan.org
Mode34443ETHmodescan.io
Arbitrum One42161ETHarbiscan.io
Arbitrum Nova42170ETHnova.arbiscan.io
Celo42220CELOceloscan.io
Avalanche C-Chain43114AVAXsnowtrace.io
Linea59144ETHlineascan.build
Berachain80094BERAberascan.com
Blast81457ETHblastscan.io
Taiko167000ETHtaikoscan.io
Scroll534352ETHscrollscan.com
Zora7777777ETHexplorer.zora.energy
Robinhood Chain4663RBHrobinhoodchain.com

Testnet chains​

EVM testnets​

ChainChain IDNative tokenExplorer
Sepolia11155111ETHsepolia.etherscan.io
Base Sepolia84532ETHsepolia.basescan.org
Arc Testnet5042002USDCtestnet.arcscan.app
Robinhood Testnet46630RBHtestnet.robinhoodchain.com

Non-EVM testnets​

ChainNetworkNative tokenExplorerFaucet
Bitcoinbitcoin-signetsBTCmempool.space/signetfaucet.coinbin.org (no captcha), signetfaucet.com
Bitcoinbitcoin-testnettBTCmempool.space/testnet— (testnet3 faucets are scarce)
Solanasolana-devnetSOLexplorer.solana.com (devnet)faucet.solana.com
XRPxrp-testnetXRPtestnet.xrpl.orgxrpl.org faucets
Cardanocardano-preprodtADAexplorer.cardano.org/preprodCardano faucet
Trontron-shastaTRXshasta.tronscan.orgshasta.tronex.io
Trontron-nileTRXnile.tronscan.orgnileex.io

Adding a chain​

Admins can add new chains via the admin API:

curl -X POST "https://api.1claw.xyz/v1/admin/chains" \
  -H "Authorization: Bearer $ADMIN_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "my-chain",
    "display_name": "My Chain",
    "chain_id": 12345,
    "rpc_url": "https://rpc.mychain.io",
    "explorer_url": "https://explorer.mychain.io",
    "native_currency": "MCH"
  }'

See the Admin API reference for update and delete endpoints.

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