kestra-io/kestra · critical · PebbleException

The 'http' function expects an argument 'uri'.

Error message

The 'http' function expects an argument 'uri'.

What it means

The 'http' Pebble function requires a 'uri' argument; this is thrown up-front by throwIfMissingArgs when uri is not present in the call.

Source

Thrown at core/src/main/java/io/kestra/core/runners/pebble/functions/HttpFunction.java:143

    private HttpRequest.RequestBody toRequestBody(Map<String, Object> args, PebbleTemplate self, int lineNumber, String contentType) {
        HttpRequest.RequestBody body;
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        Class<T> bodyClass = (Class<T>) args.get("body").getClass();
        MessageBodyWriter<T> bodyWriter = defaultMessageBodyHandlerRegistry.findWriter(Argument.of(bodyClass), MediaType.of(contentType)).orElse(FALLBACK_CONTENT_WRITER);
        bodyWriter.writeTo(Argument.of(bodyClass), MediaType.of(contentType), (T) args.get("body"), new SimpleHttpHeaders(), byteArrayOutputStream);
        try {
            body = HttpRequest.RequestBody.from(
                new ByteArrayEntity(byteArrayOutputStream.toByteArray(), ContentType.create(contentType))
            );
        } catch (IOException e) {
            throw new PebbleException(e, "Couldn't parse the request body", lineNumber, self.getName());
        }
        return body;
    }

    private void throwIfMissingArgs(Map<String, Object> args, PebbleTemplate self, int lineNumber) {
        if (!args.containsKey("uri")) {
            throw new PebbleException(null, "The 'http' function expects an argument 'uri'.", lineNumber, self.getName());
        }
    }

    @Override
    public List<String> getArgumentNames() {
        return List.of("uri", "method", "query", "body", "contentType", "headers", "options", "accept");
    }

    @Override
    public Map<String, String> getArgumentDefaults() {
        HashMap<String, String> defaults = new HashMap<>();
        defaults.put("uri", "'https://example.com'");
        defaults.put("method", "'GET'");
        defaults.put("query", null);
        defaults.put("body", null);
        defaults.put("contentType", null);
        defaults.put("headers", null);
        defaults.put("options", null);

View on GitHub (pinned to 823fada927)

Solutions

1. Pass a uri argument, e.g. http('https://example.com') or http(uri=...).
2. If uri is templated, ensure the expression resolves to a non-null string or URI before the call.

Example fix

// before
{{ http(method='GET') }}
// after
{{ http('https://example.com', method='GET') }}

{% if myUri is not empty %}{{ http(myUri) }}{% endif %}

When it happens

Trigger: Calling http() with no arguments, or only named arguments that omit uri (e.g. http(method='GET')).

Common situations: Forgot the uri, or referenced a variable for uri that resolved to null so the key was never set.

Related errors

• The 'isDayWeekInMonth()' function expects a 'date' argument.
• The 'isDayWeekInMonth()' function expects a 'dayOfWeek' argu
• The 'isDayWeekInMonth()' function expects a 'position' argum
• The 'isLastWorkingDay()' function expects a 'date' argument.
• The 'isPublicHoliday()' function expects a 'date' argument.

AI-assisted analysis of kestra-io/kestra@823fada927 (2026-08-14). Data as JSON: /api/errors/8a18e191c133b7e5. Report an issue: GitHub.