Troubleshooting
Common failure paths.
Install or startup
veyyon --version
veyyon plugin doctor
veyyon plugin doctor reports extension health and missing optional binaries/keys. Non-zero exit: fix the reported check and re-run.
Provider errors
Check API key / auth store / models.yml for that provider id, base URL, and scopes. See Models and providers.
A provider error message contains the failing status and the body the server sent, with three
limits. At most 64 KiB of the body is read, and the message states it: [truncated, showing 4096 of 65536 chars read, 134505 of 200041 bytes not read], or read stopped at 65536 bytes
when the server declared no length. Control characters and terminal escape sequences are
removed, so an error page cannot repaint the screen. Credential-shaped text is replaced with
<redacted N chars>: an Authorization or Cookie value, a bearer token, a JWT, and the
vendor key prefixes. A proxy or captive portal answering HTML instead of the provider is the
usual reason a message is truncated.
A streamed response is read one frame at a time: a line, a JSONL record, or an SSE event
ending at a blank line. One frame may occupy 64 MiB. A server or proxy that keeps sending
without ever sending the delimiter is stopped at that point, the connection is cancelled,
and the message states the protocol and both byte counts: an SSE event arrived with no blank-line dispatch: 67109376 bytes exceeded the 67108864 byte frame limit. The same
bound covers a stream of data: lines that never dispatches and a keepalive comment sent
in a loop. This failure is never retried: the next attempt reaches the same peer.
Command or edit blocked or prompting
Policy is tools.approvalMode and tools.approval, plus the working-directory and secret-use boundaries (every rung except yolo) and hard-coded flagged bash patterns: the destructive ones prompt on every rung, yolo included, and the merely dangerous ones (curl | sh, reboot, nc -e) prompt on every rung below it. There is no OS command sandbox. Schema default is auto. See Approvals and Configuration.
Truncated tool output
Tool results truncate at configured budgets; the result text should state that truncation occurred and how to continue (limit, offset, narrower query). See Bounded reads and search.