NeuG Error Codes

NeuG defines all runtime/service error codes in the protobuf file error.proto. The enums in that file are compiled into every component, so developers should treat the definitions there as the single source of truth. The table below summarizes each code and its meaning for quick reference while debugging or surfacing errors.

Category	Code	Numeric Value	Meaning
General	`OK`	0	Successful operation; no error.
General	`ERR_PERMISSION`	1001	Operation blocked due to missing permissions.
General	`ERR_VERSION_MISMATCHED`	1002	Binary/database versions are incompatible with the data directory.
General	`ERR_DIRECTORY_NOT_EXIST`	1003	Target directory path does not exist.
General	`ERR_DATABASE_LOCKED`	1004	Data directory is locked by another process.
General	`ERR_DISK_SPACE_EXHAUSTED`	1005	Insufficient disk space to continue.
General	`ERR_CORRUPTION_DETECTED`	1006	Files appear corrupted or not in the expected format.
General	`ERR_INVALID_PATH`	1007	Provided filesystem path is invalid.
General	`ERR_CONFIG_INVALID`	1008	Configuration file or values are malformed.
General	`ERR_INVALID_ARGUMENT`	1009	API/input arguments are missing or malformed.
General	`ERR_NOT_FOUND`	1010	Requested resource (vertex, file, etc.) cannot be found.
General	`ERR_NOT_SUPPORTED`	1011	Feature or operation is not implemented for the current context.
General	`ERR_INTERNAL_ERROR`	1012	Unexpected internal failure; inspect logs for stacktrace.
General	`ERR_ILLEGAL_OPERATION`	1013	Operation is not allowed in the current state/configuration.
General	`ERR_IO_ERROR`	1014	Underlying filesystem or device I/O failure.
General	`ERR_BAD_ENCODING`	1015	Unsupported encoding/decoding encountered.
General	`ERR_INVALID_FILE`	1016	Referenced file does not exist or is unreadable.
General	`ERR_EXTENSION`	1017	Failure while loading or executing an extension.
Networking / Sessions	`ERR_NETWORK`	2001	Generic network transport error.
Networking / Sessions	`ERR_SESSION_CLOSED`	2002	Session handle is closed and no longer usable.
Networking / Sessions	`ERR_CONNECTION_CLOSED`	2003	Connection dropped (server shutdown or DB closed).
Networking / Sessions	`ERR_POOL_EXHAUSTED`	2004	Connection/session pool ran out of available entries.
Networking / Sessions	`ERR_SERVICE_UNAVAILABLE`	2005	Service is offline or not yet ready.
Networking / Sessions	`ERR_LOAD_OVERFLOW`	2006	Service is overloaded; clients should retry/back off.
Networking / Sessions	`ERR_CONNECTION_ERROR`	2007	Failure establishing or maintaining a connection.
Query Compilation & Execution	`ERR_COMPILATION`	3000	Failure during query compilation stage.
Query Compilation & Execution	`ERR_QUERY_EXECUTION`	3001	Generic runtime failure while executing query plan.
Query Compilation & Execution	`ERR_QUERY_SYNTAX`	3002	Query syntax or semantics invalid.
Query Compilation & Execution	`ERR_QUERY_TIMEOUT`	3003	Query exceeded configured execution time limit.
Query Compilation & Execution	`ERR_CONCURRENT_WRITE`	3004	Conflicting concurrent write detected.
Query Compilation & Execution	`ERR_CODEGEN_ERROR`	3005	Failure during query code generation.
Query Compilation & Execution	`ERR_EMPTY_RESULT`	3006	Planner inferred empty result set.
Query Compilation & Execution	`ERR_NOT_INITIALIZED`	3007	Database/session not initialized before query execution.
Transactions & WAL	`ERR_TX_STATE_CONFLICT`	4001	Transaction state conflict (e.g., invalid transitions).
Transactions & WAL	`ERR_WAL_WRITE_FAIL`	4002	Failed to append to the write-ahead log.
Transactions & WAL	`ERR_TX_TIMEOUT`	4003	Transaction exceeded the timeout limit.
Schema & Types	`ERR_SCHEMA_MISMATCH`	5001	Schema mismatch between operation and stored data.
Schema & Types	`ERR_INVALID_SCHEMA`	5002	Schema definition is invalid.
Schema & Types	`ERR_TYPE_CONVERSION`	5003	Illegal type conversion requested.
Schema & Types	`ERR_TYPE_OVERFLOW`	5004	Value cannot fit into the target data type.
Schema & Types	`ERR_INDEX_ERROR`	5005	Index/offset out of bounds.
Schema & Types	`ERR_PROPERTY_NOT_FOUND`	5006	Requested property missing in schema.
Deployment / Platform	`ERR_PLATFORM_ABI`	6001	ABI mismatch between binaries and host platform.
Deployment / Platform	`ERR_PY_BIND_INIT`	6002	Python binding initialization failed.
Deployment / Platform	`ERR_ARCH_MISMATCH`	6003	Binary architecture does not match runtime environment.
Deployment / Platform	`ERR_DEPLOY_DEPENDENCY`	6004	Missing runtime dependency during deployment.
Feature Gaps	`ERR_NOT_IMPLEMENTED`	7001	Feature placeholder; not yet implemented.
General	`ERR_UNKNOWN`	9999	Unclassified error; inspect logs for context.

Tip: When adding new error codes, update proto/error.proto first, regenerate the protobuf outputs if necessary, and extend this document so other developers can discover the new code quickly.