FastSpring
FastSpring is a full-service ecommerce and merchant-of-record platform for SaaS, software, and digital product companies, handling global payments, tax compliance, subscription billing, checkout, and revenue management. The FastSpring API is a REST interface for managing orders, subscriptions, products, coupons, customers, and webhook events, secured via HTTP Basic Authentication using credentials issued from the FastSpring App Dashboard and with HMAC SHA-256 signing available for webhook payload verification.
Limited machine-readable signal and partial portal coverage — documentation a human can read, but little a machine or agent can consume without scraping.
API Evangelist profiles FastSpring the way a machine reads it — 19 machine-readable artifacts across 12 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
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 — FastSpring scores 40.8/100 (thin), with a separate agent-readiness read of 47/100 (agent ready). 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
How we profile FastSpring
Each block below is one kind of artifact we hold for FastSpring. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 12
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
Individual APIs this provider publishes, each with its own machine-readable definition.
FastSpring Accounts API
The Accounts API from FastSpring — 3 operation(s) for accounts.
FastSpring Coupons API
The Coupons API from FastSpring — 3 operation(s) for coupons.
FastSpring Data API
The Data API from FastSpring — 4 operation(s) for data.
FastSpring Events API
The Events API from FastSpring — 2 operation(s) for events.
FastSpring Invoices API
The Invoices API from FastSpring — 2 operation(s) for invoices.
FastSpring Orders API
The Orders API from FastSpring — 2 operation(s) for orders.
FastSpring Products API
The Products API from FastSpring — 3 operation(s) for products.
FastSpring Quotes API
The Quotes API from FastSpring — 3 operation(s) for quotes.
FastSpring Returns API
The Returns API from FastSpring — 2 operation(s) for returns.
FastSpring Sessions API
The Sessions API from FastSpring — 5 operation(s) for sessions.
FastSpring Subscriptions API
The Subscriptions API from FastSpring — 7 operation(s) for subscriptions.
FastSpring Webhooks API
The Webhooks API from FastSpring — 1 operation(s) for webhooks.
Scroll within the panel for all 12 ·
Open Collections 1
Open, tool-agnostic collections carry the same runnable value as Postman without locking you to one client — the portable, forkable form of the same exercise.
Open, tool-agnostic API collections (OpenAPI-derived and Bruno).
FastSpring API
OPEN COLLECTIONEvent Specifications 1
Not every API is request/response. AsyncAPI describes the event-driven and streaming side — the webhooks and channels — so the asynchronous half of the interface is documented the same way the synchronous half is.
AsyncAPI definitions for this provider's event-driven and streaming APIs.
FastSpring Webhooks
AsyncAPI 2.6 description of FastSpring's outbound webhook surface. FastSpring delivers events to a seller-configured HTTPS endpoint as HTTP POSTs with a JSON envelope of one or ...
ASYNCAPISpectral Rules 1
Governance rulesets we run against this provider's specs — the automated checks behind parts of the score. Profiling them makes the quality bar explicit and re-runnable, not a matter of opinion.
FastSpring API Rules
SPECTRALSecurity Posture 3
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Agentic Access 1
An x-agentic-access contract marks which operations are safe for an agent to run on its own and which need a human in the loop. It is the difference between an API an agent can use and one it can use safely.
Recommended x-agentic-access execution contracts for AI agents.
Resources
Every other property we hold for FastSpring — 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.
Get Started 1
Portal, sign-up, and the first successful call
Documentation 1
Reference material describing how the API behaves
Agent Surfaces 2
MCP servers, agent skills, and machine-readable catalogs
Build 1
SDKs, sample code, and the tooling you integrate with
Access & Security 3
Authentication, authorization, and security posture
Operate 1
Status, limits, changes, and where to get help
Commercial 1
Pricing, plans, and the legal terms of use
Company 3
The organization behind the API
Other 1
Properties that don't map to a standard resource type
← All providers · Data indexed from github.com/api-evangelist/fastspring · machine-readable index on apis.io