--- title: How to Test GraphQL APIs with Bruno: Queries, Mutations... description: A hands-on guide to testing GraphQL APIs using Bruno, an open-source API client. It explains why REST testing habits fail with GraphQL (a query can return 200... canonical: https://daily.dev/posts/how-to-test-graphql-apis-with-bruno-queries-mutations-assertions-umrizsqyp twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: How to Test GraphQL APIs with Bruno: Queries, Mutations & Assertions | daily.dev og:description: A hands-on guide to testing GraphQL APIs using Bruno, an open-source API client. It explains why REST testing habits fail with GraphQL (a query can return 200... og:url: https://daily.dev/posts/how-to-test-graphql-apis-with-bruno-queries-mutations-assertions-umrizsqyp og:image: https://api.daily.dev/og/posts/UmRIZsqyp.png og:image:alt: How to Test GraphQL APIs with Bruno: Queries, Mutations & Assertions og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # How to Test GraphQL APIs with Bruno: Queries, Mutations & Assertions **[Bruno Blog](https://daily.dev/sources/usebruno)** · 18 min read · 0 upvotes · 0 comments ## Summary A hands-on guide to testing GraphQL APIs using Bruno, an open-source API client. It explains why REST testing habits fail with GraphQL (a query can return 200 OK while still failing inside the errors array), then walks through setting up a GraphQL request, writing three-layer assertions (transport, errors, shape/values), using variables and environments, testing mutations by verifying side effects (create, read back, clean up), covering validation/execution/auth error cases via extensions.code, and running the whole collection in CI with the Bruno CLI. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### Why does my GraphQL API return a 200 status even when the query actually failed? GraphQL can return a 200 OK status while still failing internally because errors are reported inside the response body rather than via HTTP status codes. A resolver throwing an exception, a null returned for a non-nullable field, or a missing permission all get reported in an errors array alongside a 200 status, so checking status alone will let broken responses pass as successful. _Developers hardening GraphQL test suites can dig deeper into error-handling patterns on daily.dev._ ### How should I test a GraphQL mutation to make sure it actually persisted data? Test a mutation by proving its side effect rather than just checking its response: run the mutation, capture the returned id (for example with bru.setVar() in Bruno), issue a follow-up query for that id to confirm the record exists, then delete it to clean up. A mutation can return a plausible-looking response without the write actually persisting, so a confirming read-back is the reliable check. _Anyone designing reliable write-path tests can track more API testing patterns on daily.dev._ ### What is the difference between validation errors and execution errors in a GraphQL response? Validation errors occur when a request is malformed, such as a mistyped field name or wrong variable type, and the server rejects it before running anything, typically with a GRAPHQL_VALIDATION_FAILED code and often a 4xx status. Execution errors happen after the query runs, such as a resolver throwing or returning null for a non-nullable field, and are reported in the errors array with a 200 status and a path pointing to the failing field. _Teams building resilient GraphQL error handling can follow related testing techniques on daily.dev._ ## Similar posts on daily.dev - [How to Test an API Without a Frontend](https://daily.dev/posts/how-to-test-an-api-without-a-frontend-5phbkfhlw) · Bruno Blog · 16 upvotes · 3 comments - [Angular and GraphQL: From REST to GraphQL Part 1](https://daily.dev/posts/angular-and-graphql-from-rest-to-graphql-part-1-ryvhlfldm) · Telerik · 0 upvotes · 0 comments - [3 REST API Testing Mistakes That Cost Us the Most Time \(and How We Fixed Them\)](https://daily.dev/posts/3-rest-api-testing-mistakes-that-cost-us-the-most-time-and-how-we-fixed-them--kzo04t39p) · SitePoint · 0 upvotes · 0 comments - [The GraphQL Goldmine: How to Reverse Engineer APIs for Scraping](https://daily.dev/posts/the-graphql-goldmine-how-to-reverse-engineer-apis-for-scraping-8ti6rqj9d) · Ruby Flow · 1 upvotes · 0 comments --- Tags: [#testing](https://daily.dev/tags/testing), [#cicd](https://daily.dev/tags/cicd), [#graphql](https://daily.dev/tags/graphql) [View this post on daily.dev](https://daily.dev/posts/how-to-test-graphql-apis-with-bruno-queries-mutations-assertions-umrizsqyp) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"How to Test GraphQL APIs with Bruno: Queries, Mutations & Assertions","url":"https://daily.dev/posts/how-to-test-graphql-apis-with-bruno-queries-mutations-assertions-umrizsqyp","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/how-to-test-graphql-apis-with-bruno-queries-mutations-assertions-umrizsqyp"},"datePublished":"2026-08-23T07:21:18.711Z","dateModified":"2026-08-23T07:25:08.322Z","description":"A hands-on guide to testing GraphQL APIs using Bruno, an open-source API client. 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