API Evangelist

I have spent a lot of my career sitting with teams who are proud of their API, and who have no idea what it looks like from the outside.

Yesterday I published Kin Score 0.23, the London release, and most scores in the catalog moved.

The OpenAPI Initiative announced OpenAPI 3.2 on September 23rd, 2025.

This is the first of three posts about a single extension key.

Ever since we launched APIs.io in 2014, one request has come up more than any other: can I run this inside my company?

On a planning call a few weeks ago I said something out loud that I had been sorting in my head for months: there are four ways a company reacts when I publish a Kin Score about it.

I have been saying “16% human” out loud for a couple of months.

Pipedrive uses x-tool-description, which by now is a familiar shape in this series — an agent-facing description separate from the developer one: Retrieves paginated active deals with filtering by owner, person, organization, pipeline, stage, status, and…

Version 0.23.0 of the Kin Score is live.

APIDays London is this Wednesday and Thursday, 30 September and 1 October, at Convene Sancroft next to St.

I have spent two days running our profiling pipeline hard against the backlog — a few hundred companies, each one probed the way an agent would probe it: fetch the front door, look for a documentation host, look for a machine-readable contract, look for an

MoEngage uses x-moe-mcp, in their own namespace, and it packs two quite different concerns into one object: x-moe-mcp: expose: external: true internal: true tool_description: | List all offer campaigns in the workspace.

People do not ask their LLMs for POST /v1/refunds.

Back in June I wrote that Kong Konnect has two front doors and neither one is the one I want.

Secureframe uses one key, x-mcp-description, and what they put in it is the clearest example I have found of the thing OpenAPI has never been able to express.

Now that API Evangelist is itself an MCP server, a question I used to think about abstractly has become very concrete and slightly personal: how do you nudge an LLM?

On Monday I wrote that Amazon wants agents to ask permission, but there is no form to fill in.

Every agent extension I have written about in this series marks something that already exists in the document.

I have spent a week writing about what is being added to Arazzo — SOAP, actor in the loop, RPC, GraphQL, and the functions proposal.

Yesterday I published The Gateway Is a Tired Concept, Because Gateways Are About Power, and I will own that the headline was link baity.

The Model Context Protocol has a Skills extension now.

I went to the JSON Schema office hours today, and the second half of the call turned into an idea I have not been able to stop thinking about since.

Every provider in the API Evangelist and catalog gets profiled by a pipeline.

I have been around API gateways long enough to have watched them get sold as the answer to every problem in the space, over and over, for more than a decade.

Constant Contact has two keys in their own namespace — x-ctctmcp-allow and x-ctctmcp-tool-desc.

The four pull requests I have written about this week share a trait: each one points a workflow step at something that already has a description.

Earlier today I described how 427 agent cards talk and what they do, and this afternoon I knocked on the x402 doors among them.

Amazon does not want you shopping its website with an agent.

Earlier today I laid out how 427 agent cards talk and what they do, and one line in it deserved more than a row in a table.

Of the four pull requests queued for Arazzo 1.2, this is the one with the lowest bar to being useful.

Last week I wrote about Windmill’s use of x-mcp-tool and mentioned that four providers in my catalog use that key with two incompatible value types.

In July I wrote that most published agent cards are not actually A2A.

It costs me an average of $2.00 to profile each provider listed in APIs.io.

I am working to understand what I consider “Frontier Storytelling” in today’s market, which is the stories that get told and retold on the frontier of the AI market.

This is the second half of the big city storytelling breakdown I started with Arazzo — the storytelling that works on large, regulated, established organizations rather than on the frontier.

I said in my frontier storytelling post that the moving parts I was cataloging there were not the ones enterprises need to hear.

I have been working on my APIs.json specification since 2014.

I’m returning to a healthy vantage point when it comes to API specifications.

One key, 342 occurrences, 37 OpenAPI documents. x-mcp-group in Zoho Inventory’s contracts is the highest-volume agent-facing extension deployment I found anywhere in the catalog, and it is doing something none of the other MCP vocabularies I have written…

The third pull request in the Arazzo 1.2 queue is the one I want people to read as a story about review, not just as a feature.

For most of the last six years, if you opened a JSON Schema 2020-12 document in VS Code, the editor quietly fell back to draft-07 behavior and hoped for the best.

I get asked some version of the same question every week.

Yesterday I wrote about Wistia’s nine-key agent vocabulary, which is careful, coherent, and used by exactly one company.

I have spent a good part of this series arguing for federation — as the thing MCP needs, as the right posture for governance, as the alternative to centralization in almost every place the two compete.

Every workflow language eventually runs into the step that is not an API call.

I was talking with a young Sales Development Representative (SDR) at a startup this week about companies I have knowledge about.

I sat in on the Arazzo bi-weekly call this morning, and the first thing on the agenda was a pull request that has been open since July and is, by the maintainer’s own account, ready to merge.

For the last two weeks I have been writing about the SDK generators and documentation platforms whose OpenAPI extensions have spread into other companies’ contracts.

Here is how you install BoltMCP.

I hear a version of this question constantly now, and it is usually asked with a little smirk: if I can just tell Claude “make me an API” and it does, why do I still need OpenAPI?