package github
import (
"context"
"encoding/json"
"fmt"
"strings"
ghErrors "github.com/github/github-mcp-server/pkg/errors"
"github.com/github/github-mcp-server/pkg/translations"
"github.com/google/go-github/v79/github"
"github.com/mark3labs/mcp-go/mcp"
"github.com/mark3labs/mcp-go/server"
)
// TreeEntryResponse represents a single entry in a Git tree.
type TreeEntryResponse struct {
Path string `json:"path"`
Type string `json:"type"`
Size *int `json:"size,omitempty"`
Mode string `json:"mode"`
SHA string `json:"sha"`
URL string `json:"url"`
}
// TreeResponse represents the response structure for a Git tree.
type TreeResponse struct {
SHA string `json:"sha"`
Truncated bool `json:"truncated"`
Tree []TreeEntryResponse `json:"tree"`
TreeSHA string `json:"tree_sha"`
Owner string `json:"owner"`
Repo string `json:"repo"`
Recursive bool `json:"recursive"`
Count int `json:"count"`
}
// GetRepositoryTree creates a tool to get the tree structure of a GitHub repository.
func GetRepositoryTree(getClient GetClientFn, t translations.TranslationHelperFunc) (tool mcp.Tool, handler server.ToolHandlerFunc) {
return mcp.NewTool("get_repository_tree",
mcp.WithDescription(t("TOOL_GET_REPOSITORY_TREE_DESCRIPTION", "Get the tree structure (files and directories) of a GitHub repository at a specific ref or SHA")),
mcp.WithToolAnnotation(mcp.ToolAnnotation{
Title: t("TOOL_GET_REPOSITORY_TREE_USER_TITLE", "Get repository tree"),
ReadOnlyHint: ToBoolPtr(true),
}),
mcp.WithString("owner",
mcp.Required(),
mcp.Description("Repository owner (username or organization)"),
),
mcp.WithString("repo",
mcp.Required(),
mcp.Description("Repository name"),
),
mcp.WithString("tree_sha",
mcp.Description("The SHA1 value or ref (branch or tag) name of the tree. Defaults to the repository's default branch"),
),
mcp.WithBoolean("recursive",
mcp.Description("Setting this parameter to true returns the objects or subtrees referenced by the tree. Default is false"),
mcp.DefaultBool(false),
),
mcp.WithString("path_filter",
mcp.Description("Optional path prefix to filter the tree results (e.g., 'src/' to only show files in the src directory)"),
),
),
func(ctx context.Context, request mcp.CallToolRequest) (*mcp.CallToolResult, error) {
owner, err := RequiredParam[string](request, "owner")
if err != nil {
return mcp.NewToolResultError(err.Error()), nil
}
repo, err := RequiredParam[string](request, "repo")
if err != nil {
return mcp.NewToolResultError(err.Error()), nil
}
treeSHA, err := OptionalParam[string](request, "tree_sha")
if err != nil {
return mcp.NewToolResultError(err.Error()), nil
}
recursive, err := OptionalBoolParamWithDefault(request, "recursive", false)
if err != nil {
return mcp.NewToolResultError(err.Error()), nil
}
pathFilter, err := OptionalParam[string](request, "path_filter")
if err != nil {
return mcp.NewToolResultError(err.Error()), nil
}
client, err := getClient(ctx)
if err != nil {
return mcp.NewToolResultError("failed to get GitHub client"), nil
}
// If no tree_sha is provided, use the repository's default branch
if treeSHA == "" {
repoInfo, repoResp, err := client.Repositories.Get(ctx, owner, repo)
if err != nil {
return ghErrors.NewGitHubAPIErrorResponse(ctx,
"failed to get repository info",
repoResp,
err,
), nil
}
treeSHA = *repoInfo.DefaultBranch
}
// Get the tree using the GitHub Git Tree API
tree, resp, err := client.Git.GetTree(ctx, owner, repo, treeSHA, recursive)
if err != nil {
return ghErrors.NewGitHubAPIErrorResponse(ctx,
"failed to get repository tree",
resp,
err,
), nil
}
defer func() { _ = resp.Body.Close() }()
// Filter tree entries if path_filter is provided
var filteredEntries []*github.TreeEntry
if pathFilter != "" {
for _, entry := range tree.Entries {
if strings.HasPrefix(entry.GetPath(), pathFilter) {
filteredEntries = append(filteredEntries, entry)
}
}
} else {
filteredEntries = tree.Entries
}
treeEntries := make([]TreeEntryResponse, len(filteredEntries))
for i, entry := range filteredEntries {
treeEntries[i] = TreeEntryResponse{
Path: entry.GetPath(),
Type: entry.GetType(),
Mode: entry.GetMode(),
SHA: entry.GetSHA(),
URL: entry.GetURL(),
}
if entry.Size != nil {
treeEntries[i].Size = entry.Size
}
}
response := TreeResponse{
SHA: *tree.SHA,
Truncated: *tree.Truncated,
Tree: treeEntries,
TreeSHA: treeSHA,
Owner: owner,
Repo: repo,
Recursive: recursive,
Count: len(filteredEntries),
}
r, err := json.Marshal(response)
if err != nil {
return nil, fmt.Errorf("failed to marshal response: %w", err)
}
return mcp.NewToolResultText(string(r)), nil
}
}
