GitHub App installation ID is required (GITHUB_APP_INSTALLAT

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.

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)

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.