What causes "auth: signin: no provider" in kataras/iris?

Register at least one provider (e.g. a database-backed provider) before serving auth routes

auth: signin: no provider

Error message

auth: signin: no provider

What it means

Auth.Signin returns 'auth: signin: no provider' when the Auth instance has no providers registered, so there is nothing to attempt authentication against. This is a configuration error, not a credential failure — the loop over s.providers never runs and the else branch fires. It signals the Auth service was constructed without any Signin providers attached.

Solutions

Register at least one provider (e.g. a database-backed provider) before serving auth routes
Check that provider-registration code actually runs (no early return / env guard skipping it)
Add a startup assertion that len(providers) > 0 to fail fast at boot

Example fix

// before
auth := iris.NewAuth(jwtSigner) // no providers
// after
auth := iris.NewAuth(jwtSigner)
auth.AddProvider(dbProvider)

Defensive patterns

Strategy: validation

Validate before calling

// fail fast at boot
if len(a.Providers()) == 0 {
    log.Fatal("auth: no signin providers registered")
}

Type guard

func isNoProviderErr(err error) bool { return err != nil && strings.Contains(err.Error(), "auth: signin: no provider") }

Try / catch

if _, _, err := a.Signin(ctx, user, pass); err != nil {
    if strings.Contains(err.Error(), "no provider") {
        return http.StatusServiceUnavailable // server misconfig, not user error
    }
    return http.StatusUnauthorized
}

Prevention

Register providers during DI wiring and assert at startup
Avoid env guards that silently skip provider registration
Cover Auth construction in integration tests

When it happens

Trigger: Calling Signin/SigninHandler on an Auth[T] built without AddProvider (or equivalent registration) — s.providers is empty so the for-loop is skipped and the else branch errors.

Common situations: Forgetting to register any auth provider during wiring; conditional registration code that never executes (e.g. env-based setup skipped); constructing Auth in tests without providers.

Related errors

AI-assisted analysis of kataras/iris@7bedaf55a0 (2026-08-30). Data as JSON: /api/errors/4ea25075c278d08d. Report an issue: GitHub.

Appendix: source

Thrown at auth/auth.go:245

	if n := len(s.providers); n > 0 {
		for i := 0; i < n; i++ {
			p := s.providers[i]

			v, err := p.Signin(ctx, username, password)
			if err != nil {
				if i == n-1 { // last provider errored.
					return nil, nil, fmt.Errorf("auth: signin: %w", err)
				}
				// keep searching.
				continue
			}

			// found.
			t = v
			break
		}
	} else {
		return nil, nil, fmt.Errorf("auth: signin: no provider")
	}

	// sign the tokens.
	accessToken, refreshToken, err := s.sign(t)
	if err != nil {
		return nil, nil, fmt.Errorf("auth: signin: %w", err)
	}

	return accessToken, refreshToken, nil
}

func (s *Auth[T]) sign(t T) ([]byte, []byte, error) {
	// sign the tokens.
	var (
		accessStdClaims  StandardClaims
		refreshStdClaims StandardClaims
	)

View on GitHub (pinned to 7bedaf55a0)