GitHub App installation ID is required…

Error message

GitHub App installation ID is required (GITHUB_APP_INSTALLATION_ID)

What it means

Thrown by the star_repository tool handler when deps.GetClient(ctx) fails before client.Activity.Star can run. In remote/server deployments (RequestDeps) the REST client is constructed per call from token info in the request context and configured API hosts; failure wraps 'no token info in context', 'failed to get base REST URL'/'failed to get upload URL', or 'failed to create REST client'. In stdio BaseDeps mode the prebuilt client is returned and this cannot fire.

Solutions

Check the wrapped cause string to identify auth vs host-config failure
Provide a valid token with 'user' scope (starring requires it) to the server
Fix GITHUB_API_HOSTS / GITHUB_BASE_URL / GITHUB_UPLOAD_URL and restart
Pre-flight with an authenticated read like get_me to fail before attempting writes

Example fix

// before: token absent from the runtime env
//   star_repository -> "failed to get GitHub client: no token info in context"

// after
export GITHUB_PERSONAL_ACCESS_TOKEN=ghp_xxxxxxxxxxxx  # needs 'user' scope
export GITHUB_API_HOSTS=api.github.com

Defensive patterns

Strategy: try-catch

Validate before calling

func preflightGitHubClient() error {
	if os.Getenv("GITHUB_PERSONAL_ACCESS_TOKEN") == "" {
		return fmt.Errorf("missing token: star_repository cannot build a client")
	}
	return nil
}

Type guard

func isGitHubClientError(err error) bool {
	return err != nil && strings.Contains(err.Error(), "failed to get GitHub client")
}

Try / catch

result, _, err := callStarRepository(ctx, owner, repo)
if err != nil {
	if isGitHubClientError(err) {
		// config fault: verify token ('user' scope) and host env; do not retry
		return fmt.Errorf("server auth/host misconfiguration: %w", err)
	}
	return err
}

Prevention

Ensure the token has 'user' scope for starring before scripting star jobs
Pre-flight auth with get_me in the same pipeline
Fail the whole batch early when the first call returns a client-construction error
Never retry client-construction errors - they are deterministic until config changes

When it happens

Trigger: Calling star_repository when the request context lacks token info, when enterprise API host env vars are malformed so URL resolution fails, or when WithEnterpriseURLs rejects a non-absolute base/upload URL.

Common situations: Token env var missing or expired in CI where starring runs; proxy stripping Authorization; enterprise base URL typos like 'github.example.com' without scheme; deployment where env vars are set after process start.

Related errors

AI-assisted analysis of github/github-mcp-server@0ea1f775a7 (2026-08-15). Data as JSON: /api/errors/051653cabb6ddc4b. Report an issue: GitHub.

Appendix: source

Thrown at internal/githubapp/githubapp.go:55

	AppID string

	// InstallationID identifies the installation whose access token is minted.
	InstallationID string

	// PrivateKeyPEM is the RSA key used to sign app JWTs.
	PrivateKeyPEM []byte

	// BaseRESTURL is the REST API base, e.g. https://api.github.com/ for
	// github.com or https://HOST/api/v3/ for GitHub Enterprise Server.
	BaseRESTURL string
}

func (c Config) validate() error {
	switch {
	case c.AppID == "":
		return errors.New("GitHub App ID or client ID is required (GITHUB_APP_ID)")
	case c.InstallationID == "":
		return errors.New("GitHub App installation ID is required (GITHUB_APP_INSTALLATION_ID)")
	case len(c.PrivateKeyPEM) == 0:
		return errors.New("GitHub App private key is required (GITHUB_APP_PRIVATE_KEY_PATH or GITHUB_APP_PRIVATE_KEY)")
	case c.BaseRESTURL == "":
		return errors.New("GitHub App REST base URL is required")
	}
	return nil
}

func parsePrivateKey(pemBytes []byte) (*rsa.PrivateKey, error) {
	block, _ := pem.Decode(pemBytes)
	if block == nil {
		return nil, errors.New("no PEM block found in private key")
	}
	if key, err := x509.ParsePKCS1PrivateKey(block.Bytes); err == nil {
		return key, nil
	}
	parsed, err := x509.ParsePKCS8PrivateKey(block.Bytes)
	if err != nil {

View on GitHub (pinned to 0ea1f775a7)