Tag Archives: openapi

11 Jan
2024

API Linting Levels

I’ve been thinking about API linting lately, partly because I work on a tool for API linting in my day job, and partly because I get quite a lot of questions from teams wanting to improve their API quality. The “best” ruleset depends entirely on your context, where you are in your API practice journey, and how much you want to invest in the API in question. I typically use a 4-levels model of API linting readiness, and I’m sharing them so that you can find yourself on the map and see where you might go from here. Continue reading →
28 Nov
2023

Add OpenAI flags to OpenAPI descriptions

With OpenAI’s new Actions feature allowing you to get a GPT that uses your own API, many new doors are open. However giving an AI an access token the keys to your API and telling it to have fun may lead you to realise that one of the doors available leads to the empty lift shaft of overwritten data, or the bottomless well of cloud bill shock. To reduce the risks, OpenAI supports an extension x-openai-isConsequential that you can add to your OpenAPI description, to indicate which endpoints should not be called without a human confirmation step.

I’m not doing much with OpenAI right now, but I do plenty with OpenAPI and the question “how do I add this field to my existing API description?” is one that I can answer! What’s more, you can use the advice in this post to add other extensions or additions to your OpenAPI descriptions using Overlays, this advice isn’t OpenAI-specific, but it’s used in the examples. Continue reading →

20 Nov
2023

When to version bump your OpenAPI description

I’ve heard a variety of bad advice (and some untruths!) regarding how to version your OpenAPI description lately. Rather than dig into those, instead I’ll share my opinion on how I like to version API descriptions in my own projects. Every API project is different, but perhaps there’s something here that can help your project too. Continue reading →
20 Jun
2023

Visualise OpenAPI with Blockly

Giving talks about OpenAPI often means lots and lots of slides of YAML. In fact, one of my talks even contains a “warning, contains yaml” slide! If you aren’t a professional yaml developer, it can be difficult to digest and learn from, and so I wanted to do better. The various elements are nested inside one another, and so I had this idea to build a representation of OpenAPI using Blockly (the tooling also used for Scratch, if you’ve seen that).

Showing tags with descriptions
Continue reading →

12 Jun
2023

Tips for better documentation with OpenAPI

I love documentation, which is supposed to be rare for software engineers. I am pretty sure that loving documentation is actually very common, but not very cool and so few people admit to it! I love reading good docs, and so I love writing them too. Between hanging out in the Write the Docs community, and recently being at the APItheDocs conference, I’ve answered a bunch of questions about getting good documentation from an OpenAPI document, so I thought I’d round them up in case it’s useful. Continue reading →
28 Feb
2023

Improve Existing OpenAPI Descriptions

I’m a firm fan of a design-first approach to building APIs, and advocate for it at every opportunity. Repeatedly. Design-first means that an API change starts in the OpenAPI description, gets reviewed and approved by the stakeholders, and then gets built afterwards.

I also live in the real world, where OpenAPI descriptions get generated from existing codebases, and engineering teams lack either the knowledge or the enthusiasm to modernise their processes. With a generated OpenAPI description, everything else that OpenAPI enables is likely to be disappointing, because the description only contains the information that was in the serverside code, and if you’re lucky some comment metadata. Enter OpenAPI Overlays, a way to describe alterations to an existing OpenAPI description that can be reapplied every time that description changes. Continue reading →

14 Dec
2020

What’s New in OpenAPI 3.1

With OpenAPI 3.1 coming “soon”, I gave a talk at APIDays Paris about what to expect. But I’m a great fan of the written word as reference so here’s a written recap of what’s in the next OpenAPI release.

Top features:
– Compatible with JSON Schema 2020-12
– Webhook support
– Many other minor improvements
Continue reading →

06 Aug
2020

Creating a Simple OpenAPI Spec

Having API descriptions in your workflow is a game-changer, but how do you get from nothing to a functioning spec in the first place? I recently made a very simple spec for a very simple API, and thought it might make a good example for anyone looking to create a spec for the first time. OpenAPI specs are very verbose so this very tiny API makes quite a manageable example! Continue reading →
21 May
2020

Custom OpenAPI Style Rules with Spectral

I work quite a bit with OpenAPI specs and with lots of specs and lots of collaborators, keeping the specs all functional (never mind tidy, consistent, or other dreamwords) is a challenge! We use spectral to check our specs, both when we work on them and in the build process. Spectral is great but it has Opinions(TM)!

For most users, running Spectral out of the box gives quite a lot of output even on an otherwise valid spec. I do think the default ruleset for Spectral is pretty good, but every situation is different so having your own ruleset to use is a good idea. This post shows how to use a ruleset and some examples. Continue reading →

18 Feb
2020

Teach Your API Test Platform to Send Callbacks

I already wrote about using Prism as an API test platform but I didn’t include an example with callbacks so this post is to fill that gap! If you didn’t read the previous post, the tl;dr is that Prism is a nodejs open source tool that can take your OpenAPI specification and then do an impression of your live API, validating the API calls sent to it and responding with the example data described in the spec. It can also follow up the API response and send an HTTP request of its own to mock the callbacks described in your OpenAPI spec. Continue reading →