Support wildcard `["*"]` in allowed-tools filtering by Copilot · Pull Request #3445 · github/gh-aw-mcpg

Copilot · 2026-04-09T16:08:01Z

buildAllowedToolSets() treats every entry in the Tools list as a literal tool name. When the gh-aw compiler emits tools: ["*"], no tool matches the literal string "*", so all tools get filtered out.

Changes

internal/server/unified.go: buildAllowedToolSets now detects "*" anywhere in the tools list via a hasWildcard() helper. Wildcard servers are skipped (not added to the filter map), same as servers with no Tools config. Logs [allowed-tools] Wildcard "*" configured for <serverID>: allowing all tools when triggered.
Tests: Wildcard cases added to TestIsToolAllowed table, plus new TestBuildAllowedToolSets_WildcardStar, TestBuildAllowedToolSets_WildcardMixed, TestIsToolAllowed_Wildcard, and TestRegisterToolsFromBackend_WildcardAllowsAll.

// Before: ["*"] builds a set with literal "*" key — nothing matches
// After:
if hasWildcard(serverCfg.Tools) {
    logger.LogInfo("backend", "[allowed-tools] Wildcard \"*\" configured for %s: allowing all tools", serverID)
    continue
}

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

example.com
- Triggering command: /tmp/go-build1981761529/b514/launcher.test /tmp/go-build1981761529/b514/launcher.test -test.testlogfile=/tmp/go-build1981761529/b514/testlog.txt -test.paniconexit0 -test.timeout=10m0s 9420�� 9420830/b336/_pkg_.a pkg/mod/github.com/tetratelabs/wazero@v1.11.0/in-ifaceassert x_amd64/vet --gdwarf-5 .io/otel/sdk/res-V=full -o x_amd64/vet (dns block)
invalid-host-that-does-not-exist-12345.com
- Triggering command: /tmp/go-build1981761529/b496/config.test /tmp/go-build1981761529/b496/config.test -test.testlogfile=/tmp/go-build1981761529/b496/testlog.txt -test.paniconexit0 -test.timeout=10m0s -w PXs3z5Xin .cfg 64/pkg/tool/linux_amd64/vet -c .io/otel/attribu/tmp/go-build2334098856/b305/vet.cfg /tmp/go-build3709420830/b148/ 64/pkg/tool/linux_amd64/vet ache�� olang.org/grpc@v1.80.0/channelz/channelz.go .cfg 64/pkg/tool/linux_amd64/vet --gdwarf-5 --64 -o 64/pkg/tool/linux_amd64/vet (dns block)
nonexistent.local
- Triggering command: /tmp/go-build1981761529/b514/launcher.test /tmp/go-build1981761529/b514/launcher.test -test.testlogfile=/tmp/go-build1981761529/b514/testlog.txt -test.paniconexit0 -test.timeout=10m0s 9420�� 9420830/b336/_pkg_.a pkg/mod/github.com/tetratelabs/wazero@v1.11.0/in-ifaceassert x_amd64/vet --gdwarf-5 .io/otel/sdk/res-V=full -o x_amd64/vet (dns block)
slow.example.com
- Triggering command: /tmp/go-build1981761529/b514/launcher.test /tmp/go-build1981761529/b514/launcher.test -test.testlogfile=/tmp/go-build1981761529/b514/testlog.txt -test.paniconexit0 -test.timeout=10m0s 9420�� 9420830/b336/_pkg_.a pkg/mod/github.com/tetratelabs/wazero@v1.11.0/in-ifaceassert x_amd64/vet --gdwarf-5 .io/otel/sdk/res-V=full -o x_amd64/vet (dns block)
this-host-does-not-exist-12345.com
- Triggering command: /tmp/go-build1981761529/b523/mcp.test /tmp/go-build1981761529/b523/mcp.test -test.testlogfile=/tmp/go-build1981761529/b523/testlog.txt -test.paniconexit0 -test.timeout=10m0s (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

Configure Actions setup steps to set up my environment, which run before the firewall is enabled
Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Add wildcard detection in buildAllowedToolSets() so that if the Tools list contains "*", the server is treated as having no restriction (same as when Tools is empty/nil). This fixes the issue where the compiler passes tools: ["*"] and the gateway filters out all tools. - Add hasWildcard() helper to detect "*" anywhere in the tools list - Log when wildcard is detected for a server - Add unit tests for wildcard in buildAllowedToolSets, isToolAllowed - Add integration test for registerToolsFromBackend with wildcard Agent-Logs-Url: https://github.com/github/gh-aw-mcpg/sessions/3811320c-55c9-44e8-bdf0-2af76abb5fc2 Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

Copilot

Pull request overview

Adds support for wildcard "*" in per-server allowed-tools filtering so configs emitted as tools: ["*"] correctly allow all tools instead of filtering everything out.

Changes:

Update buildAllowedToolSets() to detect "*" (anywhere in the list) and treat it as “allow all” by skipping filter-set creation (with an info log).
Add unit/integration test coverage for wildcard-only and mixed wildcard configurations.

Show a summary per file

File	Description
internal/server/unified.go	Implements wildcard detection for allowed-tools set building and logs when wildcard enables allow-all.
internal/server/call_backend_tool_test.go	Extends `TestIsToolAllowed` table with wildcard cases.
internal/server/allowed_tools_integration_test.go	Adds targeted tests ensuring wildcard configs allow all tools and don’t filter tool registration.

Copilot's findings

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Files reviewed: 3/3 changed files
Comments generated: 1

Copilot · 2026-04-09T17:20:25Z

internal/server/unified.go

 // buildAllowedToolSets converts the per-server Tools lists from the config into pre-computed
 // map[string]bool sets for O(1) lookup. Servers with no Tools list are not added to the map,
-// which signals that all tools are permitted.
+// which signals that all tools are permitted. A wildcard entry ["*"] is treated the same as
+// an empty list (all tools allowed).
 func buildAllowedToolSets(cfg *config.Config) map[string]map[string]bool {
 	sets := make(map[string]map[string]bool)
 	if cfg == nil {
 		return sets
 	}
 	for serverID, serverCfg := range cfg.Servers {
 		if len(serverCfg.Tools) > 0 {
+			// Treat ["*"] as "allow all" — skip adding to the filter map
+			if hasWildcard(serverCfg.Tools) {
+				logger.LogInfo("backend", "[allowed-tools] Wildcard \"*\" configured for %s: allowing all tools", serverID)


The doc/comment text says only a wildcard entry ["*"] is treated as allow-all, but the implementation treats "*" anywhere in the Tools list as allow-all (see hasWildcard(serverCfg.Tools) and the mixed-list tests). Please update the docstring and inline comment to reflect the actual semantics (e.g., "if the Tools list contains '*' anywhere").

Update docstring and inline comment to reflect that "*" anywhere in the Tools list (not just as the sole entry) triggers allow-all behavior. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Initial plan

c8ab0e5

Copilot AI assigned Copilot and lpcox Apr 9, 2026

Copilot started work on behalf of lpcox April 9, 2026 17:05 View session

Copilot AI linked an issue Apr 9, 2026 that may be closed by this pull request

Support wildcard ["*"] in allowed-tools filtering #3443

Closed

5 tasks

Copilot AI changed the title ~~[WIP] Fix wildcard '*' handling in allowed-tools filtering~~ Support wildcard ["*"] in allowed-tools filtering Apr 9, 2026

Copilot finished work on behalf of lpcox April 9, 2026 17:17

Copilot AI requested a review from lpcox April 9, 2026 17:17

lpcox marked this pull request as ready for review April 9, 2026 17:17

Copilot AI review requested due to automatic review settings April 9, 2026 17:17

Copilot started reviewing on behalf of lpcox April 9, 2026 17:18 View session

Copilot AI reviewed Apr 9, 2026

View reviewed changes

docs: clarify wildcard matches anywhere in Tools list

4e0dc14

Update docstring and inline comment to reflect that "*" anywhere in the Tools list (not just as the sole entry) triggers allow-all behavior. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

lpcox merged commit 24416ef into main Apr 9, 2026
14 checks passed

lpcox deleted the copilot/support-wildcard-in-allowed-tools branch April 9, 2026 17:58

This was referenced Apr 9, 2026

Smoke Test: Copilot - 24205280040 #3461

Closed

Smoke Test: Copilot - 24205396754 #3462

Closed

lpcox mentioned this pull request Apr 9, 2026

[gateway] Fix tool wildcard filtering: tools: ["*"] keeps 0 tools instead of allowing all #3475

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Copilot AI mentioned this pull request Apr 10, 2026

No-op: wildcard tool filtering fix already merged #3488

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Support wildcard `["*"]` in allowed-tools filtering#3445

Support wildcard `["*"]` in allowed-tools filtering#3445
lpcox merged 3 commits intomainfrom
copilot/support-wildcard-in-allowed-tools

Copilot AI commented Apr 9, 2026 •

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Pull request overview

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Copilot AI commented Apr 9, 2026 •

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