Error Codes

This page covers the stable error-code families exposed by Vaylix and how clients should interpret them.

Since version: deterministic codes have been part of the protocol contract since early releases; the canonical code contract was documented explicitly in 0.9.0.

Caveat: Codes are stable identifiers. Human-readable messages may improve over time, but client behavior should key off the code, not the message text.

Families

Prefix	Scope	Meaning
`CMD-*`	Command parser	Text command parsing and arity failures
`TRN-*`	Transport	Framing, negotiation, checksum, compression, and I/O failures
`ENG-*`	Engine	WAL, snapshot, manifest, keyring, and storage failures
`SRV-*`	Server	Auth, RBAC, rate limiting, TLS, maintenance, replication, and admin failures

Common command and transport codes

Code	Meaning
`CMD-002`	Unknown command
`CMD-003`	Invalid command arity
`TRN-005`	Protocol version mismatch
`TRN-006`	Frame too large
`TRN-009`	Frame checksum mismatch
`TRN-014`	Protocol negotiation failed
`TRN-018`	Protocol state violation

Common engine and server codes

Code	Meaning
`ENG-007`	Persisted checksum validation failed
`ENG-009`	Unsupported storage format
`ENG-010`	Storage migration required
`SRV-007`	Authentication required
`SRV-008`	Authentication failed
`SRV-017`	Permission denied
`SRV-027`	Backup path rejected
`SRV-028`	Audit chain verification failed
`SRV-031`	Authentication locked
`SRV-035`	Replication acknowledgement timeout
`SRV-037`	Follower write rejected

Client guidance

treat the code as the stable contract
surface the human-readable message to operators
do not parse behavior from message text
expect new codes to be additive in minor releases

The canonical full list lives in the core repository’s ERROR_CODES.md for the current server line.