Bumps github.com/modelcontextprotocol/go-sdk from v1.6.0 to v1.6.1 and
removes the CrossOriginProtection bypass we previously installed on the
StreamableHTTP handler.
As of go-sdk v1.6.0 the cross-origin check is opt-in: a nil
CrossOriginProtection on StreamableHTTPOptions means no check is run.
v1.6.1 also marks the field itself as deprecated (the SDK recommends
wrapping the handler with middleware instead, and the field will be
removed in v1.8.0).
This server authenticates via bearer tokens, not cookies, so the
Sec-Fetch-Site CSRF check is unnecessary and would block browser-based
MCP clients. Leaving CrossOriginProtection unset preserves that
behavior without depending on a deprecated API.
Supersedes #2541.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Ports the gating from PR #2553 onto main (the original merge landed on a
stack base that did not make it to main).
Changes:
- pkg/inventory: FeatureFlagDisable becomes []string (any-listed-on → hide).
FeatureFlagEnable stays as a single string. This avoids the AND-of-enable
semantics from the earlier proposal, which encoded dependencies rather
than rollout knobs and had no real call site. Disable-OR is the case
that does need the slice (LegacyIssueWrite below).
- pkg/github/issues.go: split IssueWrite into IssueWrite (flag-enabled,
exposes issue_fields) and LegacyIssueWrite (flag-disabled, omits it).
Both register as 'issue_write'; mutually exclusive flag annotations
pick exactly one at runtime. Refactored into a shared buildIssueWrite
helper instead of duplicating the ~250-line tool definition.
- pkg/github/issues.go: GetIssue field_values enrichment now requires
the flag at runtime. The verbose REST IssueFieldValues is always
cleared from the response.
- Existing single-flag Disable call sites converted to slices.
- New toolsnap variant issue_write_ff_remote_mcp_issue_fields.snap; the
canonical issue_write.snap is owned by LegacyIssueWrite.
- README + flag docs regenerated.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
X-Forwarded-Host and X-Forwarded-Proto were unconditionally honored when
constructing OAuth resource metadata URLs. In HTTP-mode deployments that
do not set --base-url and are not fronted by a proxy that strips these
headers, this lets an on-path client influence the URL advertised in
WWW-Authenticate and the /.well-known/oauth-protected-resource body.
This is a hardening change rather than a true vulnerability — exploiting
it requires HTTP without --base-url plus an attacker already positioned
to inject the header — but the unsafe default is worth closing.
Default behavior now derives host/scheme from r.Host and the TLS state.
Setups that rely on a trusted internal forwarder (e.g. an in-cluster
gateway that needs to preserve the originating hostname per request) can
opt back in with --trust-proxy-headers / GITHUB_TRUST_PROXY_HEADERS=1.
--base-url continues to take precedence in all cases.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
* Add CSV output for list tools under insiders mode
* fix: resolve rebase feature flag conflicts
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
* Simplify feature-flag handling: collapse CSV dual-variant + skip filtering when no checker (#2516)
* refactor: generic toolset+name sort, clarify feature flag intent
Address review feedback on #2450:
- Collapse the three near-identical sort helpers in pkg/inventory/filters.go
into a generic sortByToolsetThenName so adding new inventory item types
doesn't require copying the comparator.
- Expand the doc comments on the three *WithoutFeatureFiltering helpers to
spell out why they exist: HTTP mode builds a static (process-wide)
inventory as an upper bound, but per-request feature flags from headers
(X-MCP-Features, X-MCP-Insiders) are evaluated later, so feature-flagged
variants must be preserved here.
- Strengthen the doc comment on ResolveFeatureFlags to make the contract
explicit: user-supplied flags are validated against AllowedFeatureFlags,
but insiders expansion deliberately is not — InsidersFeatureFlags may
include server-controlled flags that are not user-toggleable.
CORS comments are intentionally left for the PR author.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
* docs(feature-flags): clarify allowed and insiders sets are independent
Also add tests covering:
- a user-toggleable flag (FeatureFlagIssuesGranular) that insiders does
not turn on automatically
- insiders mode not turning on user-only allowed flags
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
* refactor(inventory): collapse three *WithoutFeatureFiltering helpers into StaticUpperBound
The three parallel methods (AvailableToolsWithoutFeatureFiltering,
AvailableResourceTemplatesWithoutFeatureFiltering,
AvailablePromptsWithoutFeatureFiltering) were always called as a triple
in exactly two places: HTTP buildStaticInventory and its test mirror.
They exist because the dual-variant pattern (sibling tools with mirrored
FeatureFlagEnable / FeatureFlagDisable on the same name, e.g. CSV output)
makes feature filtering at static-build time impossible — both variants
must be kept and resolved per-request.
Replace the three with one method, Inventory.StaticUpperBound(ctx), that
returns (tools, resources, prompts) and carries the rationale in its
doc comment. Reduces API surface, eliminates the triplication, and makes
the single "skip feature filtering" concept obvious to readers.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
* refactor: simplify feature-flag handling
Two related simplifications, both about treating insiders as a meta flag
that expands once at startup and then stops mattering:
- Collapse CSV's dual-variant pattern into a single tool whose handler
performs a runtime feature-flag check via deps.IsFeatureEnabled. CSV
is a pure response-format toggle, not a schema change, so it does not
need the dual-name pattern that genuine schema variants (granular
issues/PRs) still use.
- When no feature checker is installed, skip feature-flag filtering and
return the full upper bound. The static HTTP inventory now uses plain
AvailableTools/Resources/Prompts; the per-request inventory always
installs a checker, so MCP registration (which serves a tool name once)
always sees a deduplicated set. The bespoke StaticUpperBound helper and
the isToolEnabledWithFeatureFlags split go away.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
* ci(mcp-diff): add insiders + per-feature configs
The mcp-diff matrix now includes:
- --insiders (and --insiders --read-only)
- one config per github.AllowedFeatureFlags entry, generated by
script/print-mcp-diff-configs so new user-controllable flags get
diffed automatically without editing the workflow
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
* docs(insiders): explain feature-flag resolution for contributors
Adds a 'How feature flags are resolved' section covering:
- Insiders is a meta flag, like 'all'/'default' for toolsets
- User input -> allowlist filter -> insiders expansion ->
server-side fallback (remote only)
- AllowedFeatureFlags vs InsidersFeatureFlags are independent
- How to add a new feature flag, including the
TestGitHubPackageDoesNotReadInsidersMode guard
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
* refactor(inventory): make feature-flag gating a regular ToolFilter
Move tool feature-flag evaluation out of isToolEnabled and into a
ToolFilter installed at the head of the pipeline by Build() when
WithFeatureChecker received a non-nil checker. The 'no checker = no
filtering' contract is now expressed structurally (the filter isn't
installed) instead of by a runtime nil check inside the helper.
Resources and prompts have no filter pipeline, so they call the now-pure
featureFlagAllowed helper behind an explicit r.featureChecker != nil
guard at the iteration site.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
* perf(inventory): cache extracted toolset IDs in sort comparator
Avoid evaluating the extractor closures up to three times per comparison.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---------
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
* fix: correct MCP features header in cors
* docs: regenerate README for CSV output toolset
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
* fix: remove duplicate MCPFeaturesHeader from CORS headers
* ci(mcp-diff): add streamable-http job with header-based configs
Adds a sibling mcp-diff-http job that exercises the streamable-http
transport against a shared HTTP server, with per-config settings supplied
via X-MCP-* request headers — mirroring how the remote server is invoked
in production (server-side defaults + per-user header overrides).
The config generator gains a -transport flag:
- stdio (default, unchanged behaviour)
- http-headers (emits headers-only configs targeting a shared server)
Two new combined entries layer multiple headers together as a smoke test
for header-merging regressions.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
* docs: regenerate after merging main
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---------
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: Sam Morrow <info@sam-morrow.com>
Co-authored-by: sammorrowdrums <sammorrowdrums@github.com>
Dynamic toolset discovery (the meta-tools enable_toolset, list_available_toolsets,
get_toolset_tools and the --dynamic-toolsets / GITHUB_DYNAMIC_TOOLSETS switch)
was a local-only feature never offered by the remote server. Removing it
deletes a meaningful chunk of branching, configuration surface and tests
for a path no longer in active use.
The deprecated closure-based NewServerToolWithDeps generic constructor was
only kept around for the dynamic tool registration path and is removed
together with it. Going forward there are exactly two constructors:
- NewServerTool — raw mcp.ToolHandler, no closure, no unmarshalling
- NewServerToolWithContextHandler[In, Out] — typed handler, deps via context
Inventory methods that only existed for the dynamic path
(ToolsForToolset, IsToolsetEnabled, EnableToolset, EnabledToolsetIDs)
are removed. ResolvedEnabledToolsets loses its dynamic flag.
Also strips dynamic references from the README, server configuration
docs, copilot-instructions, mcp-diff workflow, and conformance-test
script.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
* fix(mcp-apps): defer _meta.ui strip to per-request RegisterTools
The MCP Apps `_meta.ui` strip lived in `Builder.Build()`, which calls
`checkFeatureFlag(context.Background())`. The HTTP feature checker
(`createHTTPFeatureChecker`) reads insiders mode from the request
context — a background context never has it set, so the FF reported
MCP Apps off and the strip ran eagerly at server startup. Per-request
inventory factories then served pre-stripped tools regardless of
whether the request actually arrived on the `/insiders` route.
Symptom: `github/github-mcp-server-remote` returns 0 tools with
`_meta.ui` over HTTP `/insiders`, despite the source unconditionally
setting it on `get_me`, `issue_write`, and `create_pull_request`.
VS Code only renders MCP App UIs because of its persistent tool cache
from earlier deploys. Reproducible locally with
`cmd/github-mcp-server http --insiders` plus a vanilla curl tools/list.
Fix: drop the strip from `Build()`. Apply it in `RegisterTools(ctx,…)`
where the per-request context is in scope and the HTTP feature checker
can correctly detect insiders mode (or the remote checker can correctly
read user identity for Statsig flag lookup).
The same root cause affects `github/github-mcp-server-remote` — its
`featureflags.NewComposedFeatureFlagChecker` reads
`requestctx.User(ctx)`, which background context lacks, so the
`remote_mcp_ui_apps` Statsig flag always returned false. The fix here
covers both downstreams since `RegisterTools` is the single entry
point for tool registration.
Stdio mode is unaffected: it uses a closure-captured insiders mode
flag (`createFeatureChecker`) that does not depend on context, and the
per-request strip in `RegisterTools` produces the same outcome.
Verified end-to-end against the deployed remote tool definitions:
HTTP /insiders → 3 tools with _meta.ui (was 0)
HTTP / → 0 tools with _meta.ui (correct)
stdio --insiders → 3 tools with _meta.ui (unchanged)
stdio → 0 tools with _meta.ui (correct)
Adds:
- pkg/http: TestInsidersRoutePreservesUIMeta — pins the regression
- pkg/inventory: updates the existing strip tests to use the new
RegisterTools-as-strip-site contract via a captureRegisteredTools
helper
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
* style: gofmt handler_test.go and registry_test.go
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
* lint: address revive (context-as-argument) and unused checkFeatureFlag
- Reorder captureRegisteredTools params to put context.Context first
- Remove dead Builder.checkFeatureFlag (was only called by Build's
former MCP Apps strip, now done in RegisterTools via the Inventory
receiver's checkFeatureFlag instead)
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---------
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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* Fix set_issue_fields mutation: use correct inline fragments for IssueFieldValue union
The mutation response struct used a single inline fragment
'... on IssueFieldDateValue' with a 'Name' field that doesn't exist
on that type (only IssueFieldSingleSelectValue has 'name'). This
caused GraphQL validation to fail with:
Field 'name' doesn't exist on type 'IssueFieldDateValue'
Since GraphQL validates the entire document (including response
selection sets) before executing any operation, the mutation never
fired at all — no fields were ever set regardless of input.
Fix by adding correct inline fragments for all four union types:
- IssueFieldTextValue (value)
- IssueFieldSingleSelectValue (name)
- IssueFieldDateValue (value)
- IssueFieldNumberValue (value)
* Update test mock to match corrected inline fragments
* Update handler_test.go formatting
Add NormalizeContentType middleware that strips optional parameters
(e.g. charset=utf-8) from application/json Content-Type headers before
the request reaches the Go SDK's StreamableHTTP handler, which performs
strict string matching.
Per RFC 8259, the charset parameter is redundant for JSON but must be
accepted per HTTP semantics.
Fixes#2333
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Rebase PR #2282 onto main (post-#2332) and unify feature flag
allowlists into a single source of truth.
- Add MCPAppsFeatureFlag, AllowedFeatureFlags, InsidersFeatureFlags,
and ResolveFeatureFlags in feature_flags.go
- AllowedFeatureFlags includes all user-controllable flags (MCP Apps +
granular), InsidersFeatureFlags only includes MCPAppsFeatureFlag
- HeaderAllowedFeatureFlags() now delegates to AllowedFeatureFlags
- Builder uses feature checker instead of insidersMode bool
- Remove InsidersOnly field from ServerTool and WithInsidersMode from
Builder
- HTTP feature checker uses ResolveFeatureFlags for per-request
resolution with insiders expansion
- Tool handlers check MCPAppsFeatureFlag via IsFeatureEnabled instead
of InsidersMode
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
The HTTP server now respects the same static CLI flags as the stdio
server: --toolsets, --tools, --exclude-tools, --read-only,
--dynamic-toolsets, and --insiders.
A static inventory is built once at startup from these flags, producing
a pre-filtered tool/resource/prompt universe. Per-request headers
(X-MCP-Toolsets, X-MCP-Tools, etc.) can only narrow within these
bounds, never expand beyond them. When no static flags are set, the
existing behavior is preserved — headers have full access to all
toolsets.
Fixes#2156
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Instead of new CLI flags (--server-name, --server-title), reuse the
existing string override mechanism that already supports tool title/
description overrides throughout the codebase.
Users can now configure the server name and title via:
- GITHUB_MCP_SERVER_NAME / GITHUB_MCP_SERVER_TITLE env vars
- "SERVER_NAME" / "SERVER_TITLE" keys in github-mcp-server-config.json
This is consistent with how all other user-visible strings are
overridden (e.g. GITHUB_MCP_TOOL_GET_ME_USER_TITLE). No new struct
fields or CLI flags are needed.
Co-authored-by: SamMorrowDrums <4811358+SamMorrowDrums@users.noreply.github.com>
Allows users running multiple GitHub MCP Server instances (e.g., for
github.com and GitHub Enterprise Server) to override the server name and
title in the MCP initialization response.
- Add --server-name / GITHUB_SERVER_NAME flag+env to override name
- Add --server-title / GITHUB_SERVER_TITLE flag+env to override title
- Defaults remain "github-mcp-server" and "GitHub MCP Server"
- Applies to both stdio and HTTP server modes
- Add tests for default and custom name/title
Co-authored-by: SamMorrowDrums <4811358+SamMorrowDrums@users.noreply.github.com>
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* Move scope storage into its own context key, separately from token info.
This allows us to provide scopes seperately in the remote server, where
we have scopes before we do the auth.
* Skip token extraction if token info already exists in context.
This is to avoid redundant token extraction in remote setup where token info may have already been extracted earlier in the request lifecycle.
* Check for existing scopes in context before fetching from GitHub API in scope challenge middleware
* Return error type for unknown tools in inventory builder and handle it in HTTP handler
Create a shared mcp.SchemaCache in RunHTTPServer and pass it through
to each per-request MCP Server via ServerOptions. This avoids repeated
JSON schema reflection and resolution when a new Server is created for
every request in stateless mode, matching the pattern used by the
remote server.
JoannaaKL