Errors and Compatibility

Verified against: Pinned source and release revisions, Qwertycoin mainnet where applicable, 2026-09-29.

Three layers can fail independently:

1. HTTP transport/authentication (non-2xx, timeout, malformed body).

2. JSON-RPC envelope (error.code/error.message, no usable result).

3. Method-level status, booleans, counts or trust flags inside a successful result.

Core daemon error codes include invalid parameters/heights/address/blob, busy/internal states, block rejection, restricted method/parameters, regtest requirement, RPC-payment errors and unsupported bootstrap behavior. Wallet codes cover address/payment/transaction errors, denied/restricted operations, wallet state, insufficient unlocked funds, password/keys/metadata, multisig, daemon connectivity and background-sync constraints. Refer to the pinned error-code headers linked by the source matrix; clients must preserve unknown future codes.

Never retry a timed-out spending or relay request blindly. First query wallet history/transfer state, derived transaction hash if known, daemon mempool and canonical chain. Retry only after proving the original action did not occur; no general idempotency guarantee is documented.

Legacy aliases in RPC Inventory remain callable only where registered. Do not invent snake_case replacements for historical method names. Release v2.0.2 lacks both registrations for get_epose_diagnostics; clients must feature-detect get_version and handle method-not-found.

walletd on port 8070 and its historical REST contract are retired and incompatible with current qwertycoin-wallet-rpc JSON-RPC.