Four findings — two inline, two in the review's suppressed block.
"Expand all" wrote `sectionIds` — the sections rendered at that instant — into
`openSections`, which outlives any one skill. Pressing it while the SKILL.md
read was still in flight dropped `frontmatter`, so the section arrived collapsed
with the control offering to expand all over again; a dynamic skill did the same
to `resources`. It now expands to the complete set, and `sectionIds` decides
only the toggle's label. The new test is verified to detect the defect: with
`sectionIds` restored it fails.
`inferMimeFromUri` matched the raw path, so a percent-encoded suffix such as
`reference%2Emd` produced no MIME at all — no markdown renderer and no
frontmatter split — even though `skillUriIdentity` already treats that spelling
as the same file. It now decodes defensively, falling back to the raw path on a
malformed escape rather than throwing inside what is only a guess.
Two comment fixes, both cases of a deliberate decision being contradicted by the
prose around it. `theme/Accordion.ts` still asserted "sized to content and never
shrink; overflow moves to the root" after round 5 moved the sections back to
`flex: 0 1 auto` with a floor — the exact stale rationale that makes a
load-bearing layout easy to regress. And the component doc, the
`onReadSkillFile` doc in `useServerCommands.tsx` and a `test-servers` fixture
comment all still said skill files are read only when the user asks to verify
them, one of them still naming the removed "View SKILL.md" button. All three now
separate reading (on selection, and not a load under SEP-2640) from verification
(strictly on demand).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01R4441JdNLZerCVM7mDDSfB
Signed-off-by: cliffhall <cliff@futurescale.com>
The pane was one scrolling column: SKILL.md sat below the manifest behind a
"View SKILL.md" button, the frontmatter pushed it further out of view, and
nothing could be put away.
It is now a flex column that does not scroll as a whole. Conformance,
Resources, Frontmatter and Skill Resource are four collapsible sections of one
`disclosure` accordion, and the file viewer claims the remaining height and
scrolls internally.
The viewer's flex-basis is 0, not auto, and that is load-bearing: `auto` makes
an item's basis its content height, and a rendered document is ~1,795px for the
data-analysis fixture. That basis joined the sum the container distributes,
over-constraining the column so the shrink factors crushed the siblings —
Conformance to a 2px panel, Resources to zero — with their contents spilling
over the headers below. Collapsing the viewer removed the giant basis, so the
symptom appeared on collapse-then-reopen. Open sections also carry a `mih`
floor, since the disclosure CSS sets `min-height: 0` on an active item.
Frontmatter now follows the displayed file rather than the selected skill.
Both halves come from one `splitSkillFile` call, so the section and the viewer
cannot disagree, and a file with no frontmatter renders no section at all.
Also: SKILL.md loads on selection (a `resources/read` is not a load under
SEP-2640), the manifest highlights on hover with each URI a button that swaps
the viewed file, both whole-skill actions moved to the pane header, and the
Conformance badge goes yellow for a warnings-only entry instead of green.
Flat CSS properties moved out of call sites into theme variants (ThemeText
gains four; a new ThemeTable takes the manifest font size).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01R4441JdNLZerCVM7mDDSfB
Signed-off-by: cliffhall <cliff@futurescale.com>
- SkillsScreen: track "Verify all" batches in a MAP keyed by manifest, not
one slot. A slot remembers only the most recent batch, so A running →
start B → return to A left A's button enabled and a second worker pool
could be started on top of A's first, doubling the concurrency cap. The
round-7 test switched to B but never STARTED B's batch, which is exactly
why it missed this; it now does, and fails against the old single slot.
- test-servers/skills.ts: pass `result` schemas to `setRequestHandler` for
both custom methods, and type the three builders from them, so a shape
change in `toEntry` / `listSkillsPage` fails `tsc` rather than shipping a
fixture that claims to conform. Declared locally rather than imported
from `core/mcp/skillsSchemas.ts`: a fixture validated against the
client's own schema could never catch the client being wrong.
One correction to the review's premise on that second point: the SDK does
NOT require `{ params, result }`, and supplying `result` does not validate
the response. Its own doc on `RequestHandlerSchemas` says `result` is
optional and "no runtime validation is performed on the result" — it types
the handler's return value. The change is worth making for that
compile-time check; it does not do what was claimed.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018kfrH3uRNUM4JAk1reKtyY
Signed-off-by: cliffhall <cliff@futurescale.com>
- useServerCommands: require the returned URI to match the requested one
in `onReadSkillFile`. The "a single-block response must be the block we
asked for" fallback is right for a viewer and wrong here: these bytes
are hashed against the requested URI's advertised digest, so accepting
a block the server labelled `b.md` would verify one file's content
against another file's digest — and could report it `verified`. A
normalized equivalent is still accepted (a server may echo a resolved
`..`), but two unparseable URIs do not compare equal, and the error
names what came back instead.
- test-servers/skills.ts: build each `SKILL.md` FROM its frontmatter
object. Three fixtures listed one description and served another, which
is an undocumented extra violation — SEP-2640 requires the listed and
served frontmatter to be identical — and would have made phase 3's
frontmatter check report a finding these fixtures were not built to
demonstrate. Deriving one from the other makes that drift impossible
rather than merely fixed.
The PR description's severity table also still described the round-1
contract (limits as errors, digest/size/description as warnings) while
the code says the reverse. Rewritten to match, with the MUST/SHOULD split
stated rather than implied.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018kfrH3uRNUM4JAk1reKtyY
Signed-off-by: cliffhall <cliff@futurescale.com>
Most of this round re-reported code the previous commit already changed
(it generated 0 new comments). Two findings were genuinely open.
- SkillsScreen: give "View SKILL.md" and "Fetch with skills/get" the same
attempt ordering `verifyRow` got in round 3. Both were still
last-completion-wins within one manifest: a double click whose older
request settled last replaced the newer result. One shared `isStale`
helper now covers all three actions — a result is dropped when its
manifest was invalidated OR a later click already wrote.
- test-servers/skills.ts + docs: stop calling all three edge cases
"non-conforming". `resources: "dynamic"` is a LEGAL wire form for
generated content — it is unverifiable, not invalid, which is exactly
why the checker reports it as a warning. The prose contradicted the
code it was describing. Now: one legal-but-unverifiable case and two
actual violations.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018kfrH3uRNUM4JAk1reKtyY
Signed-off-by: cliffhall <cliff@futurescale.com>
Two of these reverse round 4, which asked for the opposite. Where the
readings conflict I took the permissive one: a wrong tightening rejects
conforming servers, a wrong loosening only fails to report something.
- skills.ts: stop requiring the `skill:` scheme. SEP-2640 says a server
SHOULD use `skill://` and explicitly allows a domain-native scheme, so
round 4's requirement handed a conforming `github://…` skill a false
`malformed-uri` and skipped its name and root checks. Containment is
scheme-independent — it compares against THIS entry's own root — so the
traversal fix that requirement came packaged with is unaffected.
- skills.ts: the 512-entry and 16 MiB limits are warnings. Both are
SHOULD NOTs for a server and MAYs for a host, so calling them errors
contradicted the "error = a MUST was broken" contract round 4
established and told authors a permitted skill was invalid.
- skills.ts: `skillEntriesMatch` compares canonically — keys sorted,
manifest sorted by URI. `JSON.stringify` treated key order and manifest
order as differences, though neither carries meaning.
- SkillsScreen: a differing `skills/get` is "a different snapshot"
(yellow), not a disagreement (red). The SEP defines it as a fresh
point-in-time read, so a skill that changed since the listing
legitimately differs.
- useServerCommands: route `onGetSkill` through the command-scoped OAuth
recovery like every other server command. An expired authorization
rendered an error and stopped there — no reauthorization, no retry.
- test-servers/skills.ts: stamp the modern base result envelope
(`resultType` / `ttlMs` / `cacheScope`) on every skills result. The SDK
stamps it only for methods in its own codec, and `skills/*` are
consumer-owned, so a 2026-era connection was receiving results without
it. Unconditional rather than per era: the modern leg builds a server
per request, so there is no era to branch on at registration time, and
on legacy they are three members no codec inspects.
- composable-test-server: remove the `skills.directoryRead` option. It was
publicly settable and advertised a method nothing serves, producing the
exact false capability the fixture exists to help catch. `skills` is now
a plain boolean; the flag returns in phase 3 (#2248) with its handler.
Still not changed: whether a modern `skills/list` RESULT SCHEMA must
require that envelope. Stamping it server-side is free; requiring it
client-side would reject servers on a reading nobody has checked against
the normative text. #2248 owns settling it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018kfrH3uRNUM4JAk1reKtyY
Signed-off-by: cliffhall <cliff@futurescale.com>
- skills.ts: decide root containment on NORMALIZED URIs. A raw prefix
check passed `skill://acme/billing/refunds/../other.md`, which starts
with the advertised root but resolves outside it — a traversal the
conformance report was reporting as clean.
- skills.ts: `normalizeSkillUri` also rejects a relative string, so
`demo/SKILL.md` is `malformed-uri` rather than a skill path, and an
opaque-path URI (`skill:demo/..`), which the parser leaves un-normalized
and on which containment cannot be decided.
- skills.ts: `missing-description` is an error. SEP-2640 requires it, so
an absent one must not read as "0 errors" in the conformance summary.
- managedSkillsState: call `markResponseRejected` for a decode rejection,
as every managed list does. An invalid `skills/list` result was showing
in the Protocol tab as a clean success.
- SkillsScreen: per-row attempt token. The manifest key cannot tell two
verifications of the SAME row apart, so a double click (or a row button
pressed during "Verify all") let an older read finish last and overwrite
the newer verdict.
- SkillsScreen: disable "Verify all" while a batch runs. The concurrency
cap is per invocation, so repeated clicks stacked pools — 4, then 8,
then 12.
- SkillsScreen: include the finding index in each issue alert's key. Three
identical URIs produce two `duplicate-resource` findings with the same
code and URI, and React was free to drop the extras — hiding findings in
exactly the malformed input this view exists to inspect.
- test-servers/skills.ts: register `skills/list` and `skills/get` through
the PUBLIC `setRequestHandler` with explicit param schemas. The private
`_requestHandlers` map is now reached only to wrap `resources/read`,
which has to chain onto the SDK's handler rather than replace it — the
one thing the public API cannot express, and the comment now says so
instead of citing the tasks fixture.
- test-servers/skills.ts: raise `-32602` for an unknown `skills/get` URI.
A plain Error mapped to a generic server failure, making the fixture
non-conforming outside its three documented bad cases.
- clients/web/README.md: the paragraph named four contracts while still
saying the smoke "drives all three".
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018kfrH3uRNUM4JAk1reKtyY
Signed-off-by: cliffhall <cliff@futurescale.com>
- SkillsScreen: key verdicts and React elements by manifest ROW INDEX,
not URI. The checker deliberately tolerates a duplicated URI so it can
report `duplicate-resource`; a URI key collided those rows into one
verdict, so verifying either updated both and "Verify all" raced two
different digest/size declarations into the same slot.
- SkillsScreen: hold the invalidation generation in React state keyed by
the manifest, not a ref bumped during render. `useValueChange` runs its
callback during render and requires setState-only purity — an abandoned
render left the ref incremented and silently discarded a live
verification.
- SkillsScreen: title a size disagreement "Size mismatch" and render its
reason. `verifySkillResource` catches it before hashing, so the alert
was showing "actual undefined" under "Digest mismatch".
- SkillsScreen: pass `contents` to ContentViewer so a base64 SKILL.md
renders. The text-block form substituted "" and painted a blank preview
for a file verification had just read correctly.
- skills.ts: add `malformed-size` for a size that is not a non-negative
safe integer, and exclude such values from the 16 MiB total. A negative
one could pull the sum back under the limit and hide a violation.
- managedSkillsState: make the overlap guard per-session instead of a
boolean. A disconnect during an in-flight walk left it set, so the
reconnect's own load no-oped and was never retried — permanently, if
the stale request never settled. A stale `finally` can no longer clear
the live session's guard either.
- skillsSchemas: require the `{ skill }` envelope for `skills/get`. The
accepted SEP settles it, and normalizing an inline entry would let a
non-conforming response past the one place that could report it.
- #2248 and the PR description: corrected — they said
`ReadResourceDirectoryResultSchema` was already declared, which round 1
removed. #2248 now owns defining it, and records the frontmatter
cross-check gap too.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018kfrH3uRNUM4JAk1reKtyY
Signed-off-by: cliffhall <cliff@futurescale.com>
Adds detection, enumeration, and conformance checking for the Skills
extension (`io.modelcontextprotocol/skills`) — phases 1 and 2 of #2234,
which is everything its Acceptance list names.
Skills is a *server*-declared extension, read off the connecting server's
`capabilities.extensions`, so it is deliberately absent from
`ADVERTISABLE_EXTENSIONS` — that registry is what the Inspector advertises
and the user toggles, and an entry there would be a meaningless toggle.
`skills/list` and `skills/get` are consumer-owned extension methods that
neither era codec defines, so the SDK's era gate skips them and they go out
as ordinary `client.request` calls with explicit result schemas. The
raw-wire channel modern `tasks/*` needs is not used, and the Skills tab is
not era-gated: a legacy-era server that declares the extension is serving it.
The checks are the point, not the list view. `core/mcp/skills.ts` reports
each obligation SEP-2640 states — the name/path invariant, the digest
format, the 512-entry and 16 MiB limits, and `resources: "dynamic"`, which
means integrity cannot be verified at all. Digest verification hashes the
fetched bytes with WebCrypto and returns a mismatch with both digests
attached rather than throwing, because showing a mismatch loudly is the
whole value proposition.
Files are fetched on demand: SEP-2640 is explicit that a `resources/read`
of a `SKILL.md` is not a load and confers no standing, so none of the SEP's
host machinery is implemented.
The `skills-http` fixture serves four skills over two pages, three of them
deliberately non-conforming — without those the verification code is
untestable.
Phase 3 (CLI, TUI, `resources/directory/read`, paged mode) is #2248.
Closes#2234
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018kfrH3uRNUM4JAk1reKtyY
Signed-off-by: cliffhall <cliff@futurescale.com>