API Documentation Tool
Draw the API as readers meet it, from token to endpoints to webhooks, and keep each endpoint's parameters, examples and errors one click behind it.
Free forever on the Personal plan
API documentation: an example
The API at a glance
Every endpoint, grouped by resource, with its method colour coded.
A reference behind each one
Parameters, example requests and responses, and errors for every endpoint.
Authentication first
How to get a token sits where every reader starts.
The basics
What is API documentation?
API documentation tells developers how to use an API: how to authenticate, which endpoints exist and what they do, the parameters and responses for each, the errors, rate limits and versioning, and any webhooks the API sends. It usually combines a reference with guides for common tasks.
Reference pages generated from a specification are thorough but hard to take in. A diagram of the API, grouped by resource, gives new readers a map of what exists and how the parts relate before they read about any one endpoint.
In Blueprintr every endpoint on the diagram opens a stratum with its reference, and on the Team plan a folium can generate a full reference from your OpenAPI or AsyncAPI file.
Why Blueprintr
API docs developers can find their way around
A map of the API first, the reference one click down.
A map of the API
Group endpoints by resource, colour them by method, and show the token flow and webhooks around them, so readers see what exists before they dive in.
VellumReference behind each endpoint
Give every endpoint a stratum with its parameters in a table, example requests and responses in highlighted code blocks, and its errors.
StratumGenerated from OpenAPI
On the Team plan, a folium builds an API reference from an OpenAPI or AsyncAPI file, beside your hand-written guides.
FoliumA changelog developers follow
A folium keeps a dated changelog with an RSS feed and optional email updates, so integrators hear about changes before they break.
Readable by AI assistants
A public folium without a password serves a read-only MCP endpoint, so coding assistants can read your docs directly.
Embedded in your portal
Publish the API map and embed it at the top of your developer portal; readers open each endpoint's reference in place.
Blueprints
How to
How to document an API in Blueprintr
Create a blueprint
Sign up free and create a blueprint for the API and its version.
Draw the API
Add the token flow, then a container per resource with an endpoint box for each method and path.
Add the webhooks
Draw the events the API sends and where they go, with how they are signed.
Write each reference
Add a stratum to each endpoint with its parameters, examples and errors.
Publish it
Publish the blueprint, or generate the full reference in a folium from your OpenAPI file.
FAQ
Questions about api documentation
Is this API documentation tool free?
Drawing the API map and writing endpoint references in strata is free on the Personal plan. Folium documentation sites with generated API references and changelogs are part of the Team plan.
What should API documentation include?
How to authenticate, every endpoint with its parameters, example requests and responses, errors, rate limits, versioning, webhooks and how to verify them, and where to get help.
Can I generate API documentation from an OpenAPI file?
Yes, in a folium on the Team plan, from an OpenAPI or AsyncAPI file. Keep the API map and hand-written guides beside the generated reference.
Can I publish a changelog for my API?
Yes. A folium has a dated changelog with an RSS feed and opt-in email updates for subscribers.
Can AI coding assistants read my API docs?
Yes, if the folium is public and has no password: it serves a read-only MCP endpoint that assistants can connect to. Any page can also be exported as markdown.
Can I keep partner API docs private?
Yes. Share a blueprint privately with named people, or keep a folium private to your organisation or unlisted with a password.