WHATWG parsing would quietly read a hostname out of harness.internal/path or
user@harness.internal, authorizing the typo's hostname; other typos would sit
silently ignored until requests 403. Refuse every URL part beyond host[:port]
at plugin load.
The web GUI's folder picking was hardwired to one interaction: a native
OS chooser compiled into the gateway, unusable for remote deployments
and swappable only by editing apiproxy source.
Directory picking becomes a three-package capability seam in
packages/host: ctx.directoryPicker returns a discriminated capability —
dialog (the extracted native chooser; host-display only) or browse
(new: one-level listing + child creation over Node stdlib, hidden flags
host-stamped, symlinks followed, ancestry crumbs; remote-capable). The
gateway injects the seam, advertises the kind via
host.describe.directoryPicker, serves host.listDirectory /
host.createDirectory under browse, and answers
directory-picker-unavailable across kinds. cordis.yml is the swap
point; apps/cli keeps dialog mounted, so behavior is unchanged until
the in-app browser PR flips the default. The connection fixture serves
a deterministic browse tree; WorkspacesService gains the browse calls
the browser UI will drive. Decision record:
.agents/notes/implemented/architecture/2026-07-28-directory-picker-capability-seam.md
Markerless requests pass on any Host (a non-browser sender is the principal
and forges headers anyway); browser Host matching gains port-less entries and
WHATWG normalization; dsh derives LAN IP-literal authorities for an
all-interfaces bind and web grows --trusted-host for named ones.
The only browser-trust guard covered host.pickDirectory, while the
consequential methods (session.prompt drives bash) accepted any Host —
open to DNS rebinding, where a rebound page reads and writes the API as
if same-origin and only the Host header betrays the attacker's domain.
The pickDirectory-specific loopback guard becomes a prefix-wide fence:
Host must be loopback or an exact host[:port] from the new trustedHosts
config, an attached Origin must equal that authority, and explicit
cross-site markers are refused; requests without browser markers (curl,
tests, native clients) pass, because without a browser there is no
confused deputy. The loopback-socket check is dropped — binding policy
expresses reachability, and the fence is not an auth layer. The Agent
Note records the full threat model and the alternatives.
The master merge left the generated catalogs/module graph stale, the
python runtime closure missing dsh-session-projection (now reached
through session-title and tool-todo), and apiproxy holding a dead
session-title dependency (the bespoke title frame is retired). The four
files the merge pushed under the per-file coverage floor (commands
executor + invariant, projection registry drive tails, TUI) join the
existing TODO(gui) deferral block per the GUI-lane policy; the remaining
coverage-run failures reproduce identically on pure origin/master
(environment-bound suites: sdk process exit, TUI PTY timing, workflow
worker timing, title loader slow-boot) and are not this branch's debt.
gen-cordis-catalog type-link rows for the ProjectionDefinition surface and
CommandExecution; a sessionProjections service-role row for gen-doc-graphs;
regenerated module graph, persistence/config/cordis catalogs and api-catalog;
packages/README rows condensed back under the word ceiling; the RFC's sketch
fences marked ignore-check on both language sides (pairing re-recorded).
