Handwrite IO
Handwrite is a South Carolina based direct-mail service that writes and mails real handwritten cards on demand, and exposes that fulfillment as a small REST API at https://api.handwrite.io/v1. Four operations cover the whole surface: list the handwriting styles on the account, list the stationery and card options, send a card to between one and ten US recipients (or up to 1,000 orders in a single batch request), and fetch an order to follow it from processing through written to complete and retrieve proof images of the finished card and envelope. Authentication is a single static API key sent raw in the Authorization header, prefixed test_hw for unbilled test-mode calls or live_hw for calls that actually mail and bill. Pricing is per mailed card rather than per API call, from $2.99 down to $2.45 by volume, with the card, envelope, handwriting and postage included. The API is rate limited to 60 requests per minute per key. Handwrite also ships a Zapier integration for teams that do not want to write code.
Handwrite IO publishes 4 APIs on the APIs.io network, including Handwriting API, Orders API, Send API, and 1 more. Tagged areas include Direct Mail, Handwritten, Handwritten Notes, Cards, and Marketing.
The Handwrite IO catalog on APIs.io includes 1 Spectral governance ruleset.
Handwrite IO’s developer surface includes authentication, sandbox, documentation, API reference, getting-started guide, support, engineering blog, and 21 more developer resources.
Kin Score
APIs 4
Individual APIs this provider publishes, each with its own machine-readable definition.
Handwrite IO Handwriting API
Available handwriting styles
Handwrite IO Orders API
Order tracking and status
Handwrite IO Send API
Send handwritten notes
Handwrite IO Stationery API
Available stationery and cards
Open Collections 6
Open, tool-agnostic API collections (OpenAPI-derived and Bruno).
API Collection
OPEN COLLECTIONHandwrite IO Handwriting API
OPEN COLLECTIONHandwrite IO Handwriting Orders API
OPEN COLLECTIONHandwrite IO Handwriting Send API
OPEN COLLECTIONHandwrite IO Handwriting Stationery API
OPEN COLLECTIONHandwrite IO API
OPEN COLLECTIONPricing Plans 1
Published pricing tiers and plan structures.
Rate Limits 1
Documented rate limits and quota policies.
Handwrite Io Rate Limits
RATE LIMITSFinOps 1
Cost, billing, and metering signals for API financial operations.
Handwrite Io Finops
FINOPSSpectral Rules 1
Spectral governance rulesets for linting and validating these APIs.
Handwrite IO API Rules
SPECTRALSecurity Posture 2
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Agentic Access 1
Recommended x-agentic-access execution contracts for AI agents.
Resources
Get Started 5
Portal, sign-up, and the first successful call
Documentation 2
Reference material describing how the API behaves
Agent Surfaces 3
MCP servers, agent skills, and machine-readable catalogs
Design & Contract 5
Pagination, idempotency, versioning, errors, and events
Build 2
SDKs, sample code, and the tooling you integrate with
Access & Security 2
Authentication, authorization, and security posture
Operate 3
Status, limits, changes, and where to get help
Commercial 3
Pricing, plans, and the legal terms of use
Company 3
The organization behind the API