JSON-RPC-Error-Codes-Improvement-Proposal.md

name	category
JSON RPC Error Codes Improvement Proposal

To help developers add proper error handling in the dapp side, we need to implement custom error codes for the returned JSON RPC errors.

JSON RPC Standard errors

Code	Possible Return message	Description
-32700	Parse error	Invalid JSON was received by the server. An error occurred on the server while parsing the JSON text.
-32600	Invalid Request	The JSON sent is not a valid Request object.
-32601	Method not found	The method does not exist / is not available.
-32602	Invalid params	Invalid method parameter(s).
-32603	Internal error	Internal JSON-RPC error.
-32000 to -32099	Server error. Reserved for implementation-defined server-errors.

Custom error codes:

Code	Possible Return message	Description
1	Unauthorized	Should be used when some action is not authorized, e.g. sending from a locked account.
2	Action not allowed	Should be used when some action is not allowed, e.g. preventing an action, while another depending action is processing on, like sending again when a confirmation popup is shown to the user (?).
3	Execution error	Will contain a subset of custom errors in the data field. See below.

Custom error fields

Custom error 3 can contain custom error(s) to further explain what went wrong. They will be contained in the data field of the RPC error message as follows:

{
    code: 3,
    message: 'Execution error',
    data: [{
        code: 102,
        message: 'Innsufficient gas',
        reason: 'GAS'
    },
    {
        code: 103,
        message: 'Gas limit exceeded',
        reason: 'GAS'
    }]
}

Code	Reson values	Possible Return message	Description
100	?	X doesn't exist	Should be used when something which should be there is not found. (Doesn't apply for not found transactions or blocks. They return a success with value null)
101	ETHER ?	Requires X	Should be used for actions which require somethin else, e.g. gas or a value.
102	GAS, ETHER	X to low	Should be used when a to low value of something was given, e.g. an to low gas amount.
103	GAS	X limit exceeded	Should be used when a limit is exceeded, e.g. for the gas limit in a block.
104	CODE ?	Rejected	Should be used when an action was rejected, e.g. because of its content (to long contract code, containing wrong characters ?, should differ from -32602 - Invalid params).

Possible future error codes?

Code	Possible Return message	Description
105	Timeout	Should be used when an action timedout.
106	Conflict	Should be used when an action conflicts with another (ongoing?) action.