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.
Archive 21 implemented triplets whose shipped decisions are complete and
whose bodies no longer guide future work (one-off UI chrome, generator
applications whose scripts are self-explanatory, superseded implementation
detail, process history owned by current contracts/skills). Delete 4
rejected triplets whose premises are obsolete: the DeepReadonly proposal
(dev-invariants note now carries the alternative inline), the collapse
tool-owned presentation proposal (superseded by the shipped render-intent
union), retire-mid-turn-steering (steering is now load-bearing across
plan-mode/apiproxy/TUI), and single-session-ACP (automation-only ACP
resolved the question; multi-session isolation is pinned by tests).
Repair every inbound link: retarget intentional historical citations to
archived paths, replace decision-current citations with the surviving
authority, and fix the stale example-execute-over-tsx pointer in
pnpm-workspace.yaml. Re-record pairing sidecars and seal the archive
manifest (append-only; existing seals unchanged).
The group's convention is package suffix == provider default
(subagent-acp/'acp', subagent-spawn/'spawn', subagent-fork/'fork'), and the
provider default became dsh-sdk in the last review round — so the package
follows: @deepseek-ai/dsh-subagent-dsh-sdk at
packages/subagent/subagent-dsh-sdk, plugin name subagent-dsh-sdk,
diagnostics prefixed subagent-dsh-sdk:. The dsh echo has precedent
(dsh-llm-deepseek). Directory, fixture path, knip/tsconfig/examples
registrations, catalogs, READMEs (en+zh), and the Agent Note follow; the
sdk-client dispose ladder moves to its own module (src/dispose.ts) with the
deterministic FakeChild tier tests restored alongside it.
Master's #660 replaced dsh-subagent-subprocess with the dsh-subprocess
capability seam (ctx.subprocess + scrubbedParentEnv, tree-scoped teardown)
and moved subagent-acp onto it. Convergence for this branch's packages:
- The shared out-of-process provider vocabulary this branch had grown in
the deleted library (NO_START_CAPABILITIES, assertPositiveFinite, cwd
resolution, settleRunResult, subprocessRunHandle) moves into the subagent
seam package as out-of-process.ts — it enforces subagent-seam contracts,
not process mechanics, and both out-of-process backends now import it
from there (subagent-acp keeps master's shape otherwise).
- subagent-sdk spawns THROUGH the SDK client (the subprocess README's
documented exception for SDK-managed transports) and now applies the
seam's scrubbedParentEnv() + explicit-env merge in place of the deleted
buildChildEnv.
- sdk-client inlines the EOF→SIGTERM→SIGKILL ladder as private helpers (it
runs outside any harness context, so it cannot ride ctx.subprocess).
- The child harness fixture gains the now-required dsh-subprocess-local
entry for bash-local; the fixture cordis.yml keeps exercising the
shipped provider default.