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Contract Commands

Commands for interacting with EVM smart contracts. Requires the payment system to be enabled (payment.enabled = true).

lango contract <subcommand>

Experimental Feature

Contract interaction is experimental. Always verify contract addresses, method signatures, and ABI files before executing calls.

lango contract read

Call a view/pure contract method (read-only, no gas required). Validates the ABI and method locally; live RPC queries require a running lango serve instance.

lango contract read --address <addr> --abi <file> --method <name> [--args <csv>] [--chain-id <id>] [--output]
Flag Type Default Description
--address string required Contract address (0x...)
--abi string required Path to ABI JSON file
--method string required Method name to call
--args string "" Comma-separated method arguments
--chain-id int from config Chain ID override
--output bool false Output as JSON

Example:

$ lango contract read \
    --address 0x036CbD53842c5426634e7929541eC2318f3dCF7e \
    --abi ./erc20.json \
    --method balanceOf \
    --args 0x1234abcd5678ef901234abcdef567890abcdef12
Note: contract read requires a running RPC connection.
Use 'lango serve' and the contract_read agent tool for live queries.

Contract Read (validated)
  Address:  0x036CbD53842c5426634e7929541eC2318f3dCF7e
  Method:   balanceOf
  Args:     [0x1234abcd5678ef901234abcdef567890abcdef12]
  Chain ID: 84532

lango contract call

Execute a state-changing transaction on a smart contract. Validates the ABI and method locally; live transactions require a running lango serve instance and wallet.

lango contract call --address <addr> --abi <file> --method <name> [--args <csv>] [--value <eth>] [--chain-id <id>] [--output]
Flag Type Default Description
--address string required Contract address (0x...)
--abi string required Path to ABI JSON file
--method string required Method name to call
--args string "" Comma-separated method arguments
--value string "" ETH value to send (e.g., "0.01")
--chain-id int from config Chain ID override
--output bool false Output as JSON

Example:

$ lango contract call \
    --address 0x036CbD53842c5426634e7929541eC2318f3dCF7e \
    --abi ./erc20.json \
    --method transfer \
    --args 0x5678abcd1234ef567890abcdef1234567890abcd,1000000
Note: contract call requires a running RPC connection and wallet.
Use 'lango serve' and the contract_call agent tool for live transactions.

Contract Call (validated)
  Address:  0x036CbD53842c5426634e7929541eC2318f3dCF7e
  Method:   transfer
  Args:     [0x5678abcd1234ef567890abcdef1234567890abcd 1000000]
  Chain ID: 84532

State-Changing

Contract calls may modify blockchain state and spend gas or tokens. Always verify the method, arguments, and value before executing.

lango contract abi load

Parse and validate a contract ABI from a local JSON file. Caches the parsed ABI for subsequent read/call commands.

lango contract abi load --address <addr> --file <path> [--chain-id <id>] [--output]
Flag Type Default Description
--address string required Contract address (0x...)
--file string required Path to ABI JSON file
--chain-id int from config Chain ID override
--output bool false Output as JSON

Example:

$ lango contract abi load \
    --address 0x036CbD53842c5426634e7929541eC2318f3dCF7e \
    --file ./erc20.json
ABI Loaded
  Address:  0x036CbD53842c5426634e7929541eC2318f3dCF7e
  Chain ID: 84532
  Methods:  10
  Events:   3

$ lango contract abi load \
    --address 0x036CbD53842c5426634e7929541eC2318f3dCF7e \
    --file ./erc20.json \
    --output
{
  "address": "0x036CbD53842c5426634e7929541eC2318f3dCF7e",
  "chainId": 84532,
  "events": 3,
  "methods": 10,
  "status": "loaded"
}