lotus/documentation/en/api-troubleshooting.md

API Troubleshooting

Types: params

params must be an array. If there are no params you should still pass an empty array.

Types: TipSet

For methods such as Filecoin.StateMinerPower, where the method accepts the argument of the type TipSet, you can pass null to use the current chain head.

curl -X POST \
     -H "Content-Type: application/json" \
     --data '{ "jsonrpc": "2.0", "method": "Filecoin.StateMinerPower", "params": ["t0101", null], "id": 3 }' \
     'http://127.0.0.1:1234/rpc/v0'

Types: Sending a CID

If you do not serialize the CID as a JSON IPLD link, you will receive an error. Here is an example of a broken CURL request:

curl -X POST \
     -H "Content-Type: application/json" \
     --data '{ "jsonrpc": "2.0", "method":"Filecoin.ClientGetDealInfo", "params": ["bafyreiaxl446wlnu6t6dpq4ivrjf4gda4gvsoi4rr6mpxau7z25xvk5pl4"], "id": 0 }' \
     'http://127.0.0.1:1234/rpc/v0'

To fix it, change the params property to:

curl -X POST \
     -H "Content-Type: application/json" \
     --data '{ "jsonrpc": "2.0", "method":"Filecoin.ClientGetDealInfo", "params": [{"/": "bafyreiaxl446wlnu6t6dpq4ivrjf4gda4gvsoi4rr6mpxau7z25xvk5pl4"}], "id": 0 }' \
     'http://127.0.0.1:1234/rpc/v0'