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PHP JSON API Error Responses with RFC 9457

Return structured application/problem+json error bodies with RFC 9457 status and title fields rather than unstructured error strings.

2 views Published Oct 17, 2026 Updated Oct 17, 2026 Know-Stuff

Return structured application/problem+json error bodies with RFC 9457 status and title fields rather than unstructured error strings. The examples below demonstrate the main workflow, an edge case and one practical integration pattern.

What Does This Workflow Do?


Use the first example to see the core idea. The additional examples demonstrate validation and a separate integration scenario. Use JSON_THROW_ON_ERROR, validate decoded structure and impose size or depth limits on untrusted data.

Syntax:

The complete workflow is demonstrated below; individual calls are explained in context.

Requirements and Data Flow


There is no single function signature for this workflow. The required variables depend on the request, server configuration and libraries used in the examples.

Example 1: Basic Usage


Return structured application/problem+json error bodies with RFC 9457 status and title fields rather than unstructured error strings.

<?php
http_response_code(404);
header("Content-Type: application/problem+json");
echo json_encode(["type" => "about:blank", "title" => "Not Found", "status" => 404, "detail" => "The requested item does not exist."], JSON_THROW_ON_ERROR);

This example demonstrates the central operation. The final output depends on the supplied input and, where relevant, the runtime or connected service.

Example 2: Handling a Different Case


<?php
$invalidInput = "{broken JSON";
try { json_decode($invalidInput, true, 64, JSON_THROW_ON_ERROR); } catch (JsonException $exception) { echo "Invalid JSON"; }

The second example focuses on a different input or failure condition, so the behavior can be distinguished from the basic case.

Practical Example


<?php
$input = json_encode(["name" => "Alex", "active" => true], JSON_THROW_ON_ERROR);
$decoded = json_decode($input, true, 64, JSON_THROW_ON_ERROR);
if (!is_string($decoded["name"] ?? null)) { throw new RuntimeException("Invalid name"); }
echo $decoded["name"];

The practical example demonstrates how the same subject fits into a larger application. Use your own file paths, endpoints and validated inputs rather than copying sample settings directly.

Important Behavior and Edge Cases


  • Use JSON_THROW_ON_ERROR, validate decoded structure and impose size or depth limits on untrusted data.
  • Keep the example scoped to its stated purpose. A sample does not replace application authentication, authorization, production configuration or deployment review.
  • A response status, media type and headers are part of the HTTP contract; do not expose sensitive details in error bodies.

Comparison With Related Functions


ApproachDifference
PHP JSON API Error Responses with RFC 9457Return structured application/problem+json error bodies with RFC 9457 status and title fields rather than unstructured error strings.
HTTP status handlingCommunicates success or failure using protocol-defined response codes.

Common Beginner Mistakes


MistakeCorrect Approach
Ignoring errors from PHP JSON API Error Responses with RFC 9457Check the actual result and handle the expected error path.
Using the demonstration unchanged in productionAdapt file paths, configuration, authentication and permission rules to the application.
Treating input or returned data as trustedApply validation at input boundaries and context-aware escaping at output boundaries.

Key Takeaways


  • Use JSON_THROW_ON_ERROR, validate decoded structure and impose size or depth limits on untrusted data.
  • Keep the example scoped to its stated purpose. A sample does not replace application authentication, authorization, production configuration or deployment review.
  • A response status, media type and headers are part of the HTTP contract; do not expose sensitive details in error bodies.

Return structured application/problem+json error bodies with RFC 9457 status and title fields rather than unstructured error strings. Use this approach when its capabilities and constraints match the application. Handle invalid data, failure conditions and resource cleanup explicitly.

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