Bounds the total HTTP request, so allow modest headroom over the MCP
SDK's 4 MiB default for JSON-RPC and tool-call envelope overhead rather
than spending the whole budget on tool content.
Because the limit now exceeds the SDK default, passing it to
StreamableHTTPOptions is load-bearing: without it the SDK would cap
requests at 4 MiB and the headroom would not exist. Covered by a test
that sends a request between the two limits.
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
The middleware default was an arbitrary 10 MiB, above the 4 MiB the SDK
already enforces, so it never changed which requests were accepted.
Alias mcp.DefaultMaxRequestBodyBytes instead, making the earlier
enforcement point behaviour-preserving by construction.
Also pass the effective limit to StreamableHTTPOptions. Previously the
SDK kept its own 4 MiB default, so a larger configured
MaxRequestBodyBytes was silently capped; both layers now agree.
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Add WithMaxBodySize middleware that bounds the request body via
http.MaxBytesReader (with a fast Content-Length rejection when known),
registered first in RegisterMiddleware so it runs before any other
middleware or the MCP SDK reads or buffers the body.
WithMCPParse and WithScopeChallenge now return a clear 413 "request
body too large" response when their body read hits the limit, instead
of silently continuing.
Defaults to 10 MiB, overridable via ServerConfig.MaxRequestBodyBytes.
Fixes#3102
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
* feat(repos): add confirmed repository deletion
Add a destructive delete_repository tool that requires an exact owner/repo confirmation through multi-round-trip elicitation. Gate the tool to MCP protocol 2026-07-28 and newer across local and remote transports.
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 4b04480c-c2e9-483e-9b0f-34830b76a2f8
* refactor(inventory): generalize tool availability guards
Gate protocol-restricted tools on required elicitation capabilities and enforce direct calls inside the registered handler so SDK result finalization remains intact.
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 4b04480c-c2e9-483e-9b0f-34830b76a2f8
* feat(http): protect MRTR request state
Seal repository deletion targets for self-hosted HTTP with a stable AES-256-GCM key. Hide only delete_repository when no key is configured and expose an optional sealer interface for remote integrators.
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 4b04480c-c2e9-483e-9b0f-34830b76a2f8
* fix(repos): expire deletion confirmations
Bind sealed repository deletion state to the immutable repository ID and a ten-minute expiry. Re-check identity before deletion so replay cannot affect a recreated repository.
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 4b04480c-c2e9-483e-9b0f-34830b76a2f8
* fix(http): preserve tool and scope restrictions
Apply static allowlists before removing unavailable tools and fail closed on invalid configured tool names. Model independent OAuth requirements as conjunctive groups so repository deletion requires both delete_repo and repo.
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 4b04480c-c2e9-483e-9b0f-34830b76a2f8
* fix(repos): require protected confirmation state
Give stdio a process-local request-state sealer and make deletion fail closed without one. Preserve legacy any-of OAuth behavior globally while documenting and enforcing delete_repository's conjunctive delete_repo and repo requirements.
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 4b04480c-c2e9-483e-9b0f-34830b76a2f8
* fix(oauth): request repository deletion scope
Include delete_repo in the supported OAuth scope set used by stdio login, HTTP protected-resource metadata, and tool filtering.
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 4b04480c-c2e9-483e-9b0f-34830b76a2f8
* fix(oauth): require deletion scope opt-in
Keep delete_repo in protected-resource discovery for step-up authorization while excluding it from the default stdio OAuth grant.
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 4b04480c-c2e9-483e-9b0f-34830b76a2f8
* refactor(oauth): derive scope sets from catalog
Generate protected-resource supported scopes and the lower-risk default OAuth grant from one canonical scope definition list.
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 4b04480c-c2e9-483e-9b0f-34830b76a2f8
* refactor(scopes): own OAuth scope catalog
Move supported and default OAuth scope policy into pkg/scopes so protected-resource metadata and stdio grants derive from the scope domain package.
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 4b04480c-c2e9-483e-9b0f-34830b76a2f8
* fix(scopes): require workflow scope opt-in
Keep workflow and codespace in protected-resource discovery while excluding both from the default OAuth grant alongside delete_repo.
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 4b04480c-c2e9-483e-9b0f-34830b76a2f8
---------
Copilot-Session: 4b04480c-c2e9-483e-9b0f-34830b76a2f8
* fix(http): reject unsupported subscription streams
Use the Mcp-Method header to reject subscriptions/listen with the spec-defined 404 Method Not Found response instead of opening an idle SSE stream. Preserve SDK validation for missing or mismatched headers.
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 06d5dda1-4086-4996-8d18-152e45e611b0
* refactor(http): clarify subscription rejection
Document why header validation precedes the unsupported-method rejection and use named SDK error constants in tests.
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 06d5dda1-4086-4996-8d18-152e45e611b0
---------
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 06d5dda1-4086-4996-8d18-152e45e611b0
The server exposes a static set of tools, prompts, and resources and never
mutates them at runtime, so it never emits list_changed notifications. When
capabilities are left unset, the go-sdk infers listChanged:true from the
presence of items and advertises tools/prompts/resources list-change support
we don't actually provide - and the 2026-07-28 spec (subscriptions/listen)
tightens expectations around this.
Declare empty tools/prompts/resources capabilities in NewMCPServer so both the
stdio and remote servers advertise honestly. The remote HTTP handler already
set these explicitly; that duplication is now removed in favour of the shared
default, leaving only the remote-specific schema cache.
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 95b8432c-f280-472e-a242-d3ca6dc31f19
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>
* 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>
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.
Sam Morrow