floci-io/floci · error · RuntimeException

Failed to serialize v1 authorizer event

Error message

Failed to serialize v1 authorizer event

What it means

While building a REQUEST authorizer event (payload v1) — requestContext with accountId, apiId, httpMethod, path, stage, requestId — ApiGatewayExecuteController serializes it with objectMapper.writeValueAsString(event) and wraps any failure in RuntimeException('Failed to serialize v1 authorizer event'). The tree only contains strings, so a failure indicates a broken ObjectMapper configuration in the emulator, not bad caller input.

Source

Thrown at src/main/java/io/github/hectorvent/floci/services/apigateway/ApiGatewayExecuteController.java:1824

        putMultiValueQueryStringParameters(event, uriInfo);

        event.putObject("pathParameters");
        event.putNull("stageVariables");

        // Request context
        ObjectNode ctx = event.putObject("requestContext");
        ctx.put("accountId", regionResolver.getAccountId());
        ctx.put("apiId", apiId);
        ctx.put("httpMethod", httpMethod);
        ctx.put("path", path);
        ctx.put("resourcePath", path);
        ctx.put("stage", stageName);
        ctx.put("requestId", UUID.randomUUID().toString());

        try {
            return objectMapper.writeValueAsString(event);
        } catch (Exception e) {
            throw new RuntimeException("Failed to serialize v1 authorizer event", e);
        }
    }

    /**
     * Builds a REQUEST authorizer event in payload format version 2.0.
     * Uses the newer HTTP API-native shape with routeArn, routeKey, rawPath, and requestContext.http.
     */
    private String buildRequestAuthorizerEventV2(String httpMethod, String path, String routeKey,
                                                  String apiId, String stageName, String region,
                                                  HttpHeaders headers, UriInfo uriInfo) {
        ObjectNode event = objectMapper.createObjectNode();
        event.put("version", "2.0");
        event.put("type", "REQUEST");
        event.put("routeArn", buildMethodArn(region, apiId, stageName, httpMethod, path));
        event.put("routeKey", routeKey != null ? routeKey : "$default");
        event.put("rawPath", path);
        event.put("rawQueryString", uriInfo.getRequestUri().getRawQuery() != null
                ? uriInfo.getRequestUri().getRawQuery() : "");

View on GitHub (pinned to 62ff490619)

Solutions

1. Reproduce with the same route without the authorizer attached; if that works, the defect is in event serialization config, not auth logic.
2. Audit custom ObjectMapper producers/customizers in the build and remove them; Quarkus's default mapper handles ObjectNode fine.
3. Align Jackson versions with the Quarkus BOM (`./mvnw dependency:tree -Dincludes=com.fasterxml.jackson.*`).
4. For native images, register Jackson serializers for reflection and re-run the authorizer integration test.
5. Upstream: log the event node and rethrow as IllegalStateException so the 500 carries a diagnosable cause.

Example fix

// before
try {
    return objectMapper.writeValueAsString(event);
} catch (Exception e) {
    throw new RuntimeException("Failed to serialize v1 authorizer event", e);
}
// after
try {
    return objectMapper.writeValueAsString(event);
} catch (JsonProcessingException e) {
    LOG.errorf(e, "V1 authorizer event serialization failed; event=%s", event);
    throw new IllegalStateException("Failed to serialize v1 authorizer event", e);
}

// Floci maintainer: narrow the catch and preserve the event for triage
try {
    return objectMapper.writeValueAsString(event);
} catch (JsonProcessingException e) {
    LOG.errorf(e, "V1 authorizer event serialization failed; event=%s", event);
    throw new IllegalStateException("Failed to serialize v1 authorizer event", e);
}

When it happens

Trigger: Invoking an execute-api route protected by a REQUEST (v1) Lambda authorizer while the ObjectMapper has a failing custom serializer/module, or a custom Floci build has Jackson version conflicts. Stock builds assemble the event from plain strings (UUID, stage name, account id), so serialization cannot fail under default configuration.

Common situations: Forked emulators that customize Jackson (custom modules, date serializers, property-naming strategies), native-image packaging missing reflection metadata for the serializer, or dependency shading merging Jackson classes. The resulting 500 surfaces only on authorized routes, so it can look stage- or auth-specific.

Related errors

• Failed to serialize proxy event
• Override %s must not be blank.
• Cannot serialize to JSON: {}
• InternalServerException
• CustomResourceFailed

AI-assisted analysis of floci-io/floci@62ff490619 (2026-08-14). Data as JSON: /api/errors/8d3b2cb63db7bcce. Report an issue: GitHub.