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.

FiftyThree is profiled on the APIs.io network. Tagged areas include Company, Creativity, Design, Mobile, and iPad.

🌐 Visit website 📡 Source on GitHub

6.8/100 minimal ▬ flat Agent 0/100 human only Full breakdown ↓
scored 2026-07-27 · rubric v0.5

0 APIs

CompanyCreativityDesignMobileiPadStylusSDKAcquiredDefunct

Kin Score

Kin Score How this is scored →
scored 2026-07-27 · rubric v0.5

Composite quality — 6.8/100 · minimal

Contract Quality 0.0 / 25

Developer Ergonomics 0.0 / 20

Commercial Clarity 0.0 / 20

Operational Transparency 0.0 / 13

Governance 0.0 / 12

Discoverability 6.8 / 10

Agent readiness — 0/100 · human only

Machine-Readable Contract 0 / 18

Agentic Access Contract 0 / 15

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

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Resources

Company 1

The organization behind the API

Press

Press

Other 1

Properties that don't map to a standard resource type

Wikipedia

Wikipedia

Source (apis.yml)

aid: fiftythree
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source: []
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/fiftythree.png
name: FiftyThree
description: 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.
url: https://raw.githubusercontent.com/api-evangelist/fiftythree/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- a16z
x-tier: stub
x-tier-reason: portfolio-lead
x-status: defunct
x-acquired-by: WeTransfer
x-acquired-date: '2018-08-21'
specificationVersion: '0.20'
created: '2026-07-17'
modified: '2026-07-19'
tags:
- Company
- Creativity
- Design
- Mobile
- iPad
- Stylus
- SDK
- Acquired
- Defunct
apis: []
common:
- type: Wikipedia
  url: https://en.wikipedia.org/wiki/FiftyThree
- type: Press
  url: http://press.fiftythree.com/
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
x-enrichment:
  date: '2026-07-19'
  status: backfilled
  pass: local-v1
  note: backfilled from .gitignore signal + verified work evidence