The effective pairing default lived in two places: the CLI omitted scopes
unless --restrict was passed, and the server filled in its own literal.
handlePairAgent now always sends an explicit scopes list and both sides
reference one exported constant, DEFAULT_PAIR_SCOPES, so the default cannot
silently drift again (pinned by a server-auth source tripwire).
Three input traps closed in the same surface:
- Bare --restrict (or --restrict swallowing the next flag) parsed as "no
restriction" and silently granted FULL access, the opposite of the user's
intent. validatePairAgentFlags rejects it pre-server, before any consent
gate, so an arg error never boots a daemon.
- A scopes list could smuggle the control scope past the explicit flag:
--restrict "read,control" minted a control-scoped session with no
--control. /pair now 400s on control in a scopes list without the control
flag, and the CLI points the user at --control.
- Option typos validated only at exchange time: createSetupKey stored any
scope string and any rateLimit, so /pair returned 200 with a poisoned
setup key whose failure surfaced to the REMOTE agent at /connect as a
misleading "Invalid request body". Shared validation now runs in both
creators and throws typed InvalidScopeError; /pair and /token 400 with the
message, naming the bad scope or negative rateLimit. Also
`opts.rateLimit || 10` became `?? 10` so the documented "0 = unlimited"
survives the /pair path.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
