Add tool to list repo collaborators

Author: JoannaaKL

README.md

@@ -1256,6 +1256,14 @@ The following sets of tools are available:
   - `perPage`: Results per page for pagination (min 1, max 100) (number, optional)
   - `repo`: Repository name (string, required)
 
+- **list_repository_collaborators** - List repository collaborators
+  - **Required OAuth Scopes**: `repo`
+  - `affiliation`: Filter by affiliation. Can be one of: 'outside' (outside collaborators), 'direct' (all with permissions regardless of org membership), 'all' (all collaborators). Default: 'all' (string, optional)
+  - `owner`: Repository owner (string, required)
+  - `page`: Page number for pagination (min 1) (number, optional)
+  - `perPage`: Results per page for pagination (min 1, max 100) (number, optional)
+  - `repo`: Repository name (string, required)
+
 - **list_tags** - List tags
   - **Required OAuth Scopes**: `repo`
   - `owner`: Repository owner (string, required)

pkg/github/__toolsnaps__/list_repository_collaborators.snap

@@ -0,0 +1,45 @@
+{
+  "annotations": {
+    "readOnlyHint": true,
+    "title": "List repository collaborators"
+  },
+  "description": "List collaborators of a GitHub repository. Lists users who have access to the repository. Includes their username, ID, and role name.",
+  "inputSchema": {
+    "properties": {
+      "affiliation": {
+        "description": "Filter by affiliation. Can be one of: 'outside' (outside collaborators), 'direct' (all with permissions regardless of org membership), 'all' (all collaborators). Default: 'all'",
+        "enum": [
+          "outside",
+          "direct",
+          "all"
+        ],
+        "type": "string"
+      },
+      "owner": {
+        "description": "Repository owner",
+        "type": "string"
+      },
+      "page": {
+        "description": "Page number for pagination (min 1)",
+        "minimum": 1,
+        "type": "number"
+      },
+      "perPage": {
+        "description": "Results per page for pagination (min 1, max 100)",
+        "maximum": 100,
+        "minimum": 1,
+        "type": "number"
+      },
+      "repo": {
+        "description": "Repository name",
+        "type": "string"
+      }
+    },
+    "required": [
+      "owner",
+      "repo"
+    ],
+    "type": "object"
+  },
+  "name": "list_repository_collaborators"
+}

pkg/github/minimal_types.go

@@ -154,6 +154,13 @@ type MinimalResponse struct {
 	URL string `json:"url"`
 }
 
+// MinimalCollaborator is the trimmed output type for repository collaborators.
+type MinimalCollaborator struct {
+	Login    string `json:"login"`
+	ID       int64  `json:"id"`
+	RoleName string `json:"role_name"`
+}
+
 type MinimalProject struct {
 	ID               *int64            `json:"id,omitempty"`
 	NodeID           *string           `json:"node_id,omitempty"`

pkg/github/repositories.go

@@ -2240,3 +2240,103 @@ func UnstarRepository(t translations.TranslationHelperFunc) inventory.ServerTool
 		},
 	)
 }
+
+// ListRepositoryCollaborators creates a tool to list collaborators of a GitHub repository.
+func ListRepositoryCollaborators(t translations.TranslationHelperFunc) inventory.ServerTool {
+	return NewTool(
+		ToolsetMetadataRepos,
+		mcp.Tool{
+			Name:        "list_repository_collaborators",
+			Description: t("TOOL_LIST_REPOSITORY_COLLABORATORS_DESCRIPTION", "List collaborators of a GitHub repository. Lists users who have access to the repository. Includes their username, ID, and role name."),
+			Annotations: &mcp.ToolAnnotations{
+				Title:        t("TOOL_LIST_REPOSITORY_COLLABORATORS_USER_TITLE", "List repository collaborators"),
+				ReadOnlyHint: true,
+			},
+			InputSchema: WithPagination(&jsonschema.Schema{
+				Type: "object",
+				Properties: map[string]*jsonschema.Schema{
+					"owner": {
+						Type:        "string",
+						Description: "Repository owner",
+					},
+					"repo": {
+						Type:        "string",
+						Description: "Repository name",
+					},
+					"affiliation": {
+						Type:        "string",
+						Description: "Filter by affiliation. Can be one of: 'outside' (outside collaborators), 'direct' (all with permissions regardless of org membership), 'all' (all collaborators). Default: 'all'",
+						Enum:        []any{"outside", "direct", "all"},
+					},
+				},
+				Required: []string{"owner", "repo"},
+			}),
+		},
+		[]scopes.Scope{scopes.Repo},
+		func(ctx context.Context, deps ToolDependencies, _ *mcp.CallToolRequest, args map[string]any) (*mcp.CallToolResult, any, error) {
+			owner, err := RequiredParam[string](args, "owner")
+			if err != nil {
+				return utils.NewToolResultError(err.Error()), nil, nil
+			}
+			repo, err := RequiredParam[string](args, "repo")
+			if err != nil {
+				return utils.NewToolResultError(err.Error()), nil, nil
+			}
+			affiliation, err := OptionalParam[string](args, "affiliation")
+			if err != nil {
+				return utils.NewToolResultError(err.Error()), nil, nil
+			}
+			pagination, err := OptionalPaginationParams(args)
+			if err != nil {
+				return utils.NewToolResultError(err.Error()), nil, nil
+			}
+
+			client, err := deps.GetClient(ctx)
+			if err != nil {
+				return nil, nil, fmt.Errorf("failed to get GitHub client: %w", err)
+			}
+
+			opts := &github.ListCollaboratorsOptions{
+				Affiliation: affiliation,
+				ListOptions: github.ListOptions{
+					Page:    pagination.Page,
+					PerPage: pagination.PerPage,
+				},
+			}
+
+			collaborators, resp, err := client.Repositories.ListCollaborators(ctx, owner, repo, opts)
+			if err != nil {
+				return ghErrors.NewGitHubAPIErrorResponse(ctx,
+					"failed to list collaborators",
+					resp,
+					err,
+				), nil, nil
+			}
+			defer func() { _ = resp.Body.Close() }()
+
+			if resp.StatusCode != http.StatusOK {
+				body, err := io.ReadAll(resp.Body)
+				if err != nil {
+					return nil, nil, fmt.Errorf("failed to read response body: %w", err)
+				}
+				return ghErrors.NewGitHubAPIStatusErrorResponse(ctx, "failed to list collaborators", resp, body), nil, nil
+			}
+
+			var result []MinimalCollaborator
+			for _, c := range collaborators {
+				result = append(result, MinimalCollaborator{
+					Login:    c.GetLogin(),
+					ID:       c.GetID(),
+					RoleName: c.GetRoleName(),
+				})
+			}
+
+			r, err := json.Marshal(result)
+			if err != nil {
+				return nil, nil, fmt.Errorf("failed to marshal response: %w", err)
+			}
+
+			return utils.NewToolResultText(string(r)), nil, nil
+		},
+	)
+}

pkg/github/repositories_test.go

@@ -4376,3 +4376,123 @@ func Test_UnstarRepository(t *testing.T) {
 		})
 	}
 }
+
+func Test_ListRepositoryCollaborators(t *testing.T) {
+	// Verify tool definition once
+	serverTool := ListRepositoryCollaborators(translations.NullTranslationHelper)
+	tool := serverTool.Tool
+	require.NoError(t, toolsnaps.Test(tool.Name, tool))
+
+	schema, ok := tool.InputSchema.(*jsonschema.Schema)
+	require.True(t, ok, "InputSchema should be *jsonschema.Schema")
+
+	assert.Equal(t, "list_repository_collaborators", tool.Name)
+	assert.NotEmpty(t, tool.Description)
+	assert.True(t, tool.Annotations.ReadOnlyHint)
+	assert.Contains(t, schema.Properties, "owner")
+	assert.Contains(t, schema.Properties, "repo")
+	assert.Contains(t, schema.Properties, "affiliation")
+	assert.Contains(t, schema.Properties, "page")
+	assert.Contains(t, schema.Properties, "perPage")
+	assert.ElementsMatch(t, schema.Required, []string{"owner", "repo"})
+
+	mockCollaborators := []*github.User{
+		{
+			Login:    github.Ptr("user1"),
+			ID:       github.Ptr(int64(101)),
+			RoleName: github.Ptr("admin"),
+		},
+		{
+			Login:    github.Ptr("user2"),
+			ID:       github.Ptr(int64(102)),
+			RoleName: github.Ptr("write"),
+		},
+	}
+
+	tests := []struct {
+		name          string
+		args          map[string]any
+		mockResponses []MockBackendOption
+		wantErr       bool
+		errContains   string
+	}{
+		{
+			name: "success",
+			args: map[string]any{
+				"owner": "owner",
+				"repo":  "repo",
+			},
+			mockResponses: []MockBackendOption{
+				WithRequestMatch(
+					GetReposCollaboratorsByOwnerByRepo,
+					mockCollaborators,
+				),
+			},
+		},
+		{
+			name: "success with affiliation filter",
+			args: map[string]any{
+				"owner":       "owner",
+				"repo":        "repo",
+				"affiliation": "direct",
+			},
+			mockResponses: []MockBackendOption{
+				WithRequestMatch(
+					GetReposCollaboratorsByOwnerByRepo,
+					mockCollaborators,
+				),
+			},
+		},
+		{
+			name: "missing owner",
+			args: map[string]any{
+				"repo": "repo",
+			},
+			mockResponses: []MockBackendOption{},
+			errContains:   "missing required parameter: owner",
+		},
+		{
+			name: "missing repo",
+			args: map[string]any{
+				"owner": "owner",
+			},
+			mockResponses: []MockBackendOption{},
+			errContains:   "missing required parameter: repo",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			mockClient := github.NewClient(NewMockedHTTPClient(tt.mockResponses...))
+			deps := BaseDeps{
+				Client: mockClient,
+			}
+			handler := serverTool.Handler(deps)
+
+			request := createMCPRequest(tt.args)
+			result, err := handler(ContextWithDeps(context.Background(), deps), &request)
+			require.NoError(t, err)
+			require.NotNil(t, result)
+
+			if tt.errContains != "" {
+				textContent := getTextResult(t, result)
+				assert.Contains(t, textContent.Text, tt.errContains)
+				return
+			}
+
+			textContent := getTextResult(t, result)
+			require.NotEmpty(t, textContent.Text)
+
+			var collaborators []MinimalCollaborator
+			err = json.Unmarshal([]byte(textContent.Text), &collaborators)
+			require.NoError(t, err)
+			assert.Len(t, collaborators, 2)
+			assert.Equal(t, "user1", collaborators[0].Login)
+			assert.Equal(t, int64(101), collaborators[0].ID)
+			assert.Equal(t, "admin", collaborators[0].RoleName)
+			assert.Equal(t, "user2", collaborators[1].Login)
+			assert.Equal(t, int64(102), collaborators[1].ID)
+			assert.Equal(t, "write", collaborators[1].RoleName)
+		})
+	}
+}

pkg/github/tools.go

@@ -199,6 +199,7 @@ func AllTools(t translations.TranslationHelperFunc) []inventory.ServerTool {
 		ListStarredRepositories(t),
 		StarRepository(t),
 		UnstarRepository(t),
+		ListRepositoryCollaborators(t),
 
 		// Git tools
 		GetRepositoryTree(t),