Intents API transaction signing

The Intents API lets an agent sign transactions without ever seeing the raw private key. The vault decrypts the key inside the HSM, signs, and broadcasts. The agent only gets back a tx_hash.

• POST /v1/agents/:id/transactions signs and broadcasts
• POST /v1/agents/:id/transactions/sign signs only (BYORPC), returns signed_tx
• Unified POST /v1/agents/:id/sign takes intent_type: personal_sign, typed_data, or transaction

1. 1

   Get a human API key from the dashboard. Replace with your 1ck_ key from Settings → API Keys.

   bash Copy

   export TOKEN=1ck_your_key_here

2. 2

   Create an agent with intents_api_enabled and guardrails. Replace 0xRecipient with a real Ethereum address: use the same address in the transaction to field later.

   bash Copy

   AGENT_RESPONSE=$(curl -s -X POST "https://api.1claw.co/v1/agents" \
     -H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json" \
     -d '{
       "name": "DeFi Bot",
       "intents_api_enabled": true,
       "tx_allowed_chains": ["sepolia", "base"],
       "tx_to_allowlist": ["0xRecipient"],
       "tx_max_value_eth": "0.01",
       "tx_daily_limit_eth": "0.05"
     }')
   echo "$AGENT_RESPONSE"

3. 3

   Extract the agent id and api_key from the creation response. The agent id is at .agent.id and the api_key is at the top level. The ocv_ key is shown only once: save it.

   bash Copy

   export AGENT_ID=$(echo "$AGENT_RESPONSE" | jq -r .agent.id)
   export AGENT_API_KEY=$(echo "$AGENT_RESPONSE" | jq -r .api_key)
   echo "AGENT_ID=$AGENT_ID"
   echo "AGENT_API_KEY=$AGENT_API_KEY"

4. 4

   Provision an HSM-backed Ethereum signing key for the agent (using $AGENT_ID from the previous step). The private key lands in the __agent-keys vault.

   bash Copy

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

5. 5

   Exchange the agent api_key for a JWT (using $AGENT_ID and $AGENT_API_KEY captured earlier).

   bash Copy

   export AGENT_JWT=$(curl -s -X POST https://api.1claw.co/v1/auth/agent-token \
     -H "Content-Type: application/json" \
     -d "{\"agent_id\":\"$AGENT_ID\",\"api_key\":\"$AGENT_API_KEY\"}" | jq -r .access_token)

6. 6

   Submit a transaction on Sepolia with simulate_first so a revert returns 422 and nothing is signed. Replace 0xRecipient with a real Ethereum address. Use the same address in both tx_to_allowlist and the transaction to field.

   bash Copy

   curl -X POST "https://api.1claw.co/v1/agents/$AGENT_ID/transactions" \
     -H "Authorization: Bearer $AGENT_JWT" -H "Content-Type: application/json" \
     -d '{
       "chain": "sepolia",
       "to": "0xRecipient",
       "value": "0.001",
       "data": "0x",
       "simulate_first": true
     }'

You now have an agent that submits a simulated, guardrailed transaction with the signing key locked inside the vault.

Where this goes wrong in practice. Guardrails are configured once and then quietly outgrown, and signing failures are unusually expensive because they are irreversible.

• Value caps are set in native units and the price moves. A 0.5 ETH daily limit written when ETH was cheap is a different limit a year later, and nothing re-evaluates it.
• EIP-712 is left at the default and then widened for one integration. Typed-data signing is deny-by-default for good reason, and every allowlisted domain is a permanent widening made for a temporary need.
• Unlimited ERC-20 approvals slip through. A transfer cap bounds what one transaction moves; an approval grants standing authority to move everything later, and it looks like a small transaction at signing time.
• Simulation failures are treated as noise. A failing simulation is the cheapest warning available, and routing it to a policy rather than a log is the difference between catching a bad call and funding one.
• Gas budgets are forgotten. Value caps say nothing about fees, so an agent stuck in a retry loop drains the account in overhead while every individual transaction stays inside its limit.