FiftyThree
FiftyThree, Inc. was a New York City-based technology company that built tools for mobile creativity, best known for Paper (Apple's 2012 iPad App of the Year), the Pencil Bluetooth stylus, and Paste, a collaborative presentation tool. The company raised a Series A led by Andreessen Horowitz (a16z) in 2013 and, in July 2014, shipped the FiftyThree SDK so third-party iOS apps such as Procreate and Noteshelf could integrate the Pencil stylus (pairing, palm rejection, surface pressure). FiftyThree's assets and patents were acquired by WeTransfer on August 21, 2018, and the standalone products and developer surface were subsequently wound down. This profile is retained as a historical company record; there is no live public web API, developer portal, or OpenAPI to enrich.
Index entry only — little beyond a description and a link, and nothing machine-readable enough for an agent to act on without a human reading the site first.
FiftyThree is tracked in the API Evangelist network. This page is the human-readable profile that sits on top of the machine-readable index we maintain at apis.io.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — FiftyThree scores 6.8/100 (minimal), with a separate agent-readiness read of 0/100 (human only). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.
Kin Score
How this is scored →scored 2026-07-27 · rubric v0.5
Resources
Every other property we hold for FiftyThree — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Company 1
The organization behind the API
Other 1
Properties that don't map to a standard resource type
FiftyThree is in the network as a tracked entity. We haven't yet indexed a public API surface for it — when one is published, the artifacts, score, and agent-readiness read will appear here automatically. The source repository is where that profile is built.
← All providers · Data indexed from github.com/api-evangelist/fiftythree · machine-readable index on apis.io