[TN] Error Status Code 200

src/content/technotes/TN0047-error-status-code-200.mdx

@@ -0,0 +1,45 @@
+---
+title: Error! Status Code 200?
+subtitle: Granular error handling in your API
+description: Learn GraphQL uniquly handles errors and how that compares to traditional REST APIs.
+published: 2024-02-09
+id: TN0047
+tags: [best-practices, error-handling]
+---
+
+In the realm of API development, HTTP status codes serve as crucial indicators of request success or failure.
+However, when it comes to GraphQL, the traditional approach of using REST/HTTP error codes becomes inadequate.
+GraphQL introduces a paradigm shift in how APIs are designed and operated, rendering conventional status codes insufficient for capturing the nuances of GraphQL operations, especially in the context of parallel operations.
+
+>
+> TLDR; The GraphQL 200 status codes signify the successful processing of a request at the Apollo Router level, but they do not encapsulate the outcome of individual operations or the presence of errors within a GraphQL response.
+> Attempting to shoehorn HTTP error codes into the GraphQL paradigm overlooks the unique characteristics and capabilities of GraphQL, such as granular error handling, parallel execution, and asynchronous patterns.
+> 
+> You can learn more about status codes in GraphQL by reading the [GraphQL-over-HTTP](https://graphql.github.io/graphql-over-http/draft/) specification.
+>
+
+## Nature of GraphQL Operations
+
+In a typical REST API, each endpoint corresponds to a specific resource or action, making it straightforward to map HTTP status codes to the outcome of each request.
+However, GraphQL operates differently. Instead of multiple endpoints, GraphQL has a single endpoint that serves as an entry point for executing queries, mutations, and subscriptions.
+This unified approach allows clients to request precisely the data they need in a single round trip to the server.
+
+## Granular Error Handling
+
+GraphQL offers granular error handling through its response structure.
+In a GraphQL response, along with the data requested by the client, the server can include an array of errors, each containing detailed information about what went wrong.
+This level of granularity enables clients to understand and react to errors more effectively than traditional HTTP status codes would allow.
+
+## Parallel Execution and Partial Results
+
+One of the most powerful features of GraphQL is its ability to execute multiple operations in parallel.
+This means that even if one part of a GraphQL operation fails, other parts may still succeed.
+In contrast, REST APIs typically follow a serial execution model, where one failed request can halt the entire process.
+
+Therefore, using HTTP status codes to convey the outcome of parallel GraphQL operations would be impractical and misleading.
+
+## Significance of 200 Status Codes
+
+In GraphQL, the presence of a 200 status code indicates that the request was successful from the Apollo Router's perspective.
+This does not necessarily mean that the client received all the data it requested without any errors.
+Instead, it signifies that the GraphQL operation as a whole was processed without encountering any issues, regardless of the outcome of individual field resolvers.

src/content/technotes/_redirects

@@ -47,4 +47,5 @@
 /TN0043 /docs/technotes/TN0043-using-graphql-for-abstraction
 /TN0044 /docs/technotes/TN0044-graphql-and-rest-together
 /TN0045 /docs/technotes/TN0045-router_resource_estimator
-/TN0046 /docs/technotes/TN0046-managing-graph-environments-using-variants
+/TN0046 /docs/technotes/TN0046-managing-graph-environments-using-variants
+/TN0047 /docs/technotes/TN0047-error-status-code-200