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>
- 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>
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>
- SkillsScreen: actually call `skills/get`. The client method and its
tests existed but no production caller invoked it, so #2234's acceptance
criterion ("skills/get retrieves a single entry") was unmet and a server
author's required handler could not be exercised. The detail pane now
fetches the selected URI on demand and reports whether the fetched entry
AGREES with the one skills/list advertised — both describe the same
skill, so a disagreement is a server bug only a side-by-side fetch shows.
- core/mcp/sha256.ts: a dependency-free SHA-256, used when `crypto.subtle`
is absent. `SubtleCrypto` needs a secure context, and this app is
documented as servable over plain HTTP on a LAN IP — where every skill
verification threw and the UI reported a read failure for files it had
fetched fine. Checked against the FIPS 180-4 vectors and differentially
against WebCrypto.
- skills.ts: require the `skill:` scheme in `normalizeSkillUri`. Checking
only that a URI was hierarchical let `https://demo/SKILL.md` pass the
name and root checks — a manifest pointing anywhere on the web, reported
as conforming.
- skills.ts: `missing-digest` and `missing-size` are errors. Both are
required fields, and an omitted `size` is what lets a server slip past
the 16 MiB pre-fetch limit while the UI reports zero errors. `warning`
is now reserved for what is legal yet unverifiable — `"dynamic"`.
- SkillsScreen: key the "Verify all" batch guard to the manifest. A global
flag left a newly selected skill's button disabled until the previous
skill's reads settled — forever, if one hung.
Not changed, deliberately: whether a modern-era `skills/list` result MUST
carry the SEP-2549 caching attributes. #2234's analysis records it as open
and the review asserts the opposite; neither reading was checked against
the normative text. Leaving the schema permissive accepts a server that
omits them, while tightening on a wrong reading would reject conforming
responses — the more expensive direction. `skillsSchemas.ts` states this
and #2248 settles 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>
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>
Both handlers discarded their promise with a bare `void`. Nothing owned
those failures: `subscribeToResource` throws when the client is
disconnected, when the server declares no subscription support, and
(wrapped) on a failed request — so a subscribe that failed did nothing
visible and surfaced only as an unhandled browser rejection, while every
neighbouring command in the hook already routed through the shared
recovery.
Both now go through `runCommandInBackground`, so a mid-session 401
recovers the way it does on a refresh and any other failure toasts.
The source is `ambient`, not `resource`: a `resource` step-up failure is
routed into `readResourceState` — the read-preview panel — which
describes a read of whatever is selected rather than this subscribe, so
marking it errored would contradict a read that succeeded. Subscribing
has no panel of its own, the same position the refreshes and the
pagination toggle are in.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013hzwzS8UvBsr4yZm7o7sev
Signed-off-by: cliffhall <cliff@futurescale.com>
Copilot round 3, from its suppressed set: "a paginated paginated fetch".
The line came across verbatim with `onLoadMoreTools`, so the typo
predates this PR — fixed here since the comment is the thing being
moved.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013hzwzS8UvBsr4yZm7o7sev
Signed-off-by: cliffhall <cliff@futurescale.com>
Phase-2 step 4 of the App.tsx decomposition (#2155, under #2129/#2126).
Every command the screens issue against the live server moves into
`useServerCommands`: calling a tool, getting a prompt, reading and
subscribing to a resource, completing an argument, cancelling a task or
a call, setting either log level, refreshing or paging a list, and
flipping the pagination mode. All of them route through the
command-scoped auth recovery `useOAuthRecovery` publishes, which is why
this cluster cannot precede the OAuth one.
The three in-flight result panels move with them, behind a small
`useResultPanels` in the same file — split out only because of call
order, the same reason `useHandshakeTelemetry` sits beside
`useConnectionLifecycle`: `useOAuthRecovery` drops those panels on a
session reset and routes a step-up failure into whichever one issued
the command, and it runs before the commands hook.
The move is inert — no behavior change, #2095's per-server pagination
override included.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013hzwzS8UvBsr4yZm7o7sev
Signed-off-by: cliffhall <cliff@futurescale.com>
