labstack/echo · warning

ErrCookieNotFound

ErrCookieNotFound

Error message

cookie not found

What it means

ErrCookieNotFound is an exported sentinel error representing a missing cookie. Note that Context.Cookie delegates to the standard library http.Request.Cookie, which returns http.ErrNoCookie; Echo provides this sentinel as a semantic alternative for user code and middleware that wish to use Echo's error vocabulary. Middleware like CSRF check c.Cookie and compare against this error shape.

Solutions

1. Check the returned error and handle the missing-cookie case gracefully (redirect to login, set a new cookie)
2. Iterate c.Cookies() to see all available cookies for debugging name mismatches
3. Use errors.Is(err, http.ErrNoCookie) since Context.Cookie returns the stdlib error

Example fix

// before
cookie, err := c.Cookie("session")
if err == echo.ErrCookieNotFound { ... } // may not match stdlib error

// after
cookie, err := c.Cookie("session")
if errors.Is(err, http.ErrNoCookie) {
    return c.Redirect(http.StatusFound, "/login")
}

// Check cookie presence via Cookies() slice before Cookie()
func hasCookie(c echo.Context, name string) bool {
    for _, ck := range c.Cookies() {
        if ck.Name == name { return true }
    }
    return false
}

cookie, err := c.Cookie("session")
if err != nil {
    if errors.Is(err, http.ErrNoCookie) {
        return c.Redirect(http.StatusFound, "/login")
    }
    return err
}

When it happens

Trigger: Calling c.Cookie("session") when the request contains no Cookie header with that name. The underlying stdlib returns http.ErrNoCookie; user code may compare against echo.ErrCookieNotFound when using Echo idioms.

Common situations: First-time visitor with no session cookie. Cookie name mismatch (e.g. case sensitivity, trailing whitespace). Cookie expired and browser stopped sending it.

AI-assisted analysis of labstack/echo@05489dc173 (2026-08-04). Data as JSON: /api/errors/54491081519f3c41. Report an issue: GitHub.

Appendix: source

Thrown at httperror.go:33

	ErrUnauthorized                = &httpError{http.StatusUnauthorized}          // 401
	ErrForbidden                   = &httpError{http.StatusForbidden}             // 403
	ErrNotFound                    = &httpError{http.StatusNotFound}              // 404
	ErrMethodNotAllowed            = &httpError{http.StatusMethodNotAllowed}      // 405
	ErrRequestTimeout              = &httpError{http.StatusRequestTimeout}        // 408
	ErrStatusRequestEntityTooLarge = &httpError{http.StatusRequestEntityTooLarge} // 413
	ErrUnsupportedMediaType        = &httpError{http.StatusUnsupportedMediaType}  // 415
	ErrTooManyRequests             = &httpError{http.StatusTooManyRequests}       // 429
	ErrInternalServerError         = &httpError{http.StatusInternalServerError}   // 500
	ErrBadGateway                  = &httpError{http.StatusBadGateway}            // 502
	ErrServiceUnavailable          = &httpError{http.StatusServiceUnavailable}    // 503
)

// The following errors fall into 500 (InternalServerError) category
var (
	ErrValidatorNotRegistered = errors.New("validator not registered")
	ErrRendererNotRegistered  = errors.New("renderer not registered")
	ErrInvalidRedirectCode    = errors.New("invalid redirect status code")
	ErrCookieNotFound         = errors.New("cookie not found")
	ErrInvalidCertOrKeyType   = errors.New("invalid cert or key type, must be string or []byte")
	ErrInvalidListenerNetwork = errors.New("invalid listener network")
)

// HTTPStatusCoder is an interface that errors can implement to produce status code for HTTP response
type HTTPStatusCoder interface {
	StatusCode() int
}

// StatusCode returns status code from err if it implements HTTPStatusCoder interface.
// If err does not implement the interface, it returns 0.
func StatusCode(err error) int {
	var sc HTTPStatusCoder
	if errors.As(err, &sc) {
		return sc.StatusCode()
	}
	return 0
}

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