Errors

Retain the existing error envelope and stable machine-readable codes. The proposed Stellar adapter adds chain-specific categories without presenting a failed submit as a safely unpaid transaction.

Code	Meaning	Client response
validation_error	Invalid amount network or terms	Correct input
network_mismatch	Signer or envelope targets another environment	Switch network and rebuild
unsupported_asset	Issuer or SAC not approved	Select configured asset
authorization_required	Required account authorization absent	Request correct wallet approval
insufficient_balance	Asset balance fees or reserves unavailable	Explain funding requirement
capacity_exceeded	Funded event cannot cover new exposure	Reduce notional or select another event
intent_expired	Quote or transaction bounds expired	Refresh terms and request approval
simulation_failed	Invocation rejected before submission	Show decoded contract error
sequence_conflict	Source sequence changed	Rebuild and sign as required
oracle_unavailable	Valid fixing not available	Keep event pending and report status
submission_unknown	Outcome not yet reconciled	Poll by hash before retrying payment
upstream_error	RPC or provider unavailable	Bounded retry or route escalation

Business data access also returns unauthorized, forbidden, not-found, and rate-limit responses as appropriate. A browser user refusal is handled without implying a network failure. Never expose provider tokens, keys, or customer documents in error details.