github/github-mcp-server · error

failed to get GitHub client: %w

Error message

failed to get GitHub client: %w

What it means

uiGetLabels failed in deps.GetGQLClient(ctx): the GraphQL client (githubv4) could not be constructed from the configured auth/transport before any query ran. Same failure family as the REST GetClient error, but for the GraphQL endpoint.

Source

Thrown at pkg/github/ui_tools.go:114

			case "reviewers":
				return uiGetReviewers(ctx, deps, args, owner)
			default:
				return utils.NewToolResultError(fmt.Sprintf("unknown method: %s", method)), nil, nil
			}
		})
	st.FeatureFlagEnable = MCPAppsFeatureFlag
	return st
}

func uiGetLabels(ctx context.Context, deps ToolDependencies, args map[string]any, owner string) (*mcp.CallToolResult, any, error) {
	repo, err := RequiredParam[string](args, "repo")
	if err != nil {
		return utils.NewToolResultError(err.Error()), nil, nil
	}

	client, err := deps.GetGQLClient(ctx)
	if err != nil {
		return nil, nil, fmt.Errorf("failed to get GitHub client: %w", err)
	}

	var query struct {
		Repository struct {
			Labels struct {
				Nodes []struct {
					ID          githubv4.ID
					Name        githubv4.String
					Color       githubv4.String
					Description githubv4.String
				}
				TotalCount githubv4.Int
				PageInfo   struct {
					HasNextPage githubv4.Boolean
					EndCursor   githubv4.String
				}
			} `graphql:"labels(first: 100, after: $cursor)"`
		} `graphql:"repository(owner: $owner, name: $repo)"`

View on GitHub (pinned to 0ea1f775a7)

Solutions

1. Verify token configuration for the configured host
2. Check the GraphQL endpoint availability (curl https://<host>/api/graphql)
3. Inspect server logs for auth/transport initialization errors

token := os.Getenv("GITHUB_MCP_BACKEND_GITHUB_TOKEN")
if token == "" {
	log.Fatal("GraphQL tools need a configured token")
}
if resp, err := http.Head(graphqlURL()); err != nil || resp.StatusCode >= 500 {
	log.Fatal("GraphQL endpoint unavailable")
}

When it happens

Trigger: No or invalid token; OAuth token exchange failure; GHES host where the GraphQL endpoint (/api/graphql) is disabled or unreachable; host URL configuration resolving to an invalid GraphQL URL.

Common situations: Remote server deployments missing token env vars; GHES instances without GraphQL enabled; proxies blocking the graphql path.

Related errors

• owner is required
• failed to get GitHub client: %w
• GitHub App authentication and OAuth login (--oauth-client-id
• GitHub App installation ID is required (GITHUB_APP_INSTALLAT
• GitHub App REST base URL is required

AI-assisted analysis of github/github-mcp-server@0ea1f775a7 (2026-08-15). Data as JSON: /api/errors/1b401a77a7873a6e. Report an issue: GitHub.