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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.

FastSpring publishes 12 APIs on the APIs.io network, including Accounts API, Coupons API, Data API, and 9 more. Tagged areas include E-Commerce, Merchant of Record, Subscription Billing, Payments, and SaaS Billing.

The FastSpring catalog on APIs.io includes 1 event-driven AsyncAPI specification and 1 Spectral governance ruleset.

FastSpring’s developer surface includes authentication, documentation, pricing, signup flow, support, engineering blog, and 8 more developer resources.

🌐 Visit website 📡 Source on GitHub
32.5/100 thin ▬ flat Agent 29/100 agent aware Full breakdown ↓
scored 2026-08-20 · rubric v0.12.0
AccessSelf serve
12 APIs
E-CommerceMerchant of RecordSubscription BillingPaymentsSaaS BillingCheckoutTax Compliance

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-08-20 · rubric v0.12.0
Composite quality — 32.5/100 · thin
Contract Quality 12.2 / 21
Developer Ergonomics 2.2 / 17
Access Clarity 5.4 / 17
Operational Transparency 0.3 / 11
Contract Governance 1.4 / 10
Discoverability 6.9 / 9
Regulatory Posture 4.0 / 15
Agent readiness — 29/100 · agent aware
Machine-Readable Contract 18 / 18
Agentic Access Contract 10 / 10
Documented Reversibility 6 / 6
MCP Server 0 / 12
Machine-Readable Auth 10 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 0 / 7
Typed Event Surface 6 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
Regulatory Posture applies to this provider. Its tags matched the Payments regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.
The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/fastspring: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 12

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 for all 12

Open Collections 14

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

API Collection

OPEN COLLECTION

FastSpring Accounts API

OPEN COLLECTION

FastSpring Accounts Coupons API

OPEN COLLECTION

FastSpring Accounts Data API

OPEN COLLECTION

FastSpring Accounts Events API

OPEN COLLECTION

FastSpring Accounts Invoices API

OPEN COLLECTION

FastSpring Accounts Orders API

OPEN COLLECTION

FastSpring Accounts Products API

OPEN COLLECTION

FastSpring Accounts Quotes API

OPEN COLLECTION

FastSpring Accounts Returns API

OPEN COLLECTION

FastSpring Accounts Sessions API

OPEN COLLECTION

FastSpring Accounts Subscriptions API

OPEN COLLECTION

FastSpring Accounts Webhooks API

OPEN COLLECTION

FastSpring API

OPEN COLLECTION

Scroll for all 14

Event Specifications 1

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 ...

ASYNCAPI

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

FastSpring API Rules

7 rules · 1 errors 5 warnings 1 info

SPECTRAL

Security Posture 3

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Fastspring Authentication

http · 1 scheme

SECURITY

Fastspring Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Fastspring Trust Center

SOC 2, PCI DSS, GDPR

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Fastspring Agentic Access

51 operations · 28 acting

51 operations · 28 acting

AGENTIC

Resources

Get Started 1

Portal, sign-up, and the first successful call

Signup
Signup

Documentation 1

Reference material describing how the API behaves

Documentation
Documentation

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess
AgenticAccess
 LlmsText
LlmsText

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization

Access & Security 3

Authentication, authorization, and security posture

TrustCenter
TrustCenter
 DomainSecurity
DomainSecurity
 Authentication
Authentication

Operate 1

Status, limits, changes, and where to get help

Support
Support

Commercial 1

Pricing, plans, and the legal terms of use

Pricing
Pricing

Company 3

The organization behind the API

LinkedIn
LinkedIn
 Website
Website
 Blog
Blog

Other 1

Properties that don't map to a standard resource type

App Dashboard
App Dashboard

Source (apis.yml)

apis.yml Raw ↑ 
aid: fastspring
name: FastSpring
description: 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.
type: Index
accessModel:
  pricing: unknown
  onboarding: self-serve
  trial: false
  try_now: false
  public: false
  label: Self-serve signup
  confidence: medium
  source:
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/fastspring.png
tags:
- E-Commerce
- Merchant of Record
- Subscription Billing
- Payments
- SaaS Billing
- Checkout
- Tax Compliance
tags_raw:
- Ecommerce
- Merchant of Record
- Subscription Billing
- Payments
- SaaS Billing
- Checkout
- Tax Compliance
url: https://raw.githubusercontent.com/api-evangelist/fastspring/refs/heads/main/apis.yml
created: '2026-05-11'
modified: '2026-05-30'
specificationVersion: '0.23'
apis:
- aid: fastspring:fastspring-accounts-api
  name: FastSpring Accounts API
  description: The Accounts API from FastSpring — 3 operation(s) for accounts.
  humanURL: https://developer.fastspring.com
  baseURL: https://api.fastspring.com
  tags:
  - Account
  tags_raw:
  - Accounts
  properties:
  - type: OpenAPI
    url: openapi/fastspring-accounts-api-openapi.yml
  - type: Documentation
    url: https://developer.fastspring.com/reference
  - type: GettingStarted
    url: https://developer.fastspring.com/reference/getting-started-with-your-api
  - type: Authentication
    url: https://developer.fastspring.com/reference/authentication
  - type: Webhooks
    url: https://developer.fastspring.com/reference/webhooks
  - type: Message Security
    url: https://developer.fastspring.com/reference/message-security
  - type: AsyncAPI
    url: https://raw.githubusercontent.com/api-evangelist/fastspring/refs/heads/main/asyncapi/fastspring-asyncapi.yml
- aid: fastspring:fastspring-coupons-api
  name: FastSpring Coupons API
  description: The Coupons API from FastSpring — 3 operation(s) for coupons.
  humanURL: https://developer.fastspring.com
  baseURL: https://api.fastspring.com
  tags:
  - Coupons
  properties:
  - type: OpenAPI
    url: openapi/fastspring-coupons-api-openapi.yml
  - type: Documentation
    url: https://developer.fastspring.com/reference
  - type: GettingStarted
    url: https://developer.fastspring.com/reference/getting-started-with-your-api
  - type: Authentication
    url: https://developer.fastspring.com/reference/authentication
  - type: Webhooks
    url: https://developer.fastspring.com/reference/webhooks
  - type: Message Security
    url: https://developer.fastspring.com/reference/message-security
  - type: AsyncAPI
    url: https://raw.githubusercontent.com/api-evangelist/fastspring/refs/heads/main/asyncapi/fastspring-asyncapi.yml
- aid: fastspring:fastspring-data-api
  name: FastSpring Data API
  description: The Data API from FastSpring — 4 operation(s) for data.
  humanURL: https://developer.fastspring.com
  baseURL: https://api.fastspring.com
  tags:
  - Data
  properties:
  - type: OpenAPI
    url: openapi/fastspring-data-api-openapi.yml
  - type: Documentation
    url: https://developer.fastspring.com/reference
  - type: GettingStarted
    url: https://developer.fastspring.com/reference/getting-started-with-your-api
  - type: Authentication
    url: https://developer.fastspring.com/reference/authentication
  - type: Webhooks
    url: https://developer.fastspring.com/reference/webhooks
  - type: Message Security
    url: https://developer.fastspring.com/reference/message-security
  - type: AsyncAPI
    url: https://raw.githubusercontent.com/api-evangelist/fastspring/refs/heads/main/asyncapi/fastspring-asyncapi.yml
- aid: fastspring:fastspring-events-api
  name: FastSpring Events API
  description: The Events API from FastSpring — 2 operation(s) for events.
  humanURL: https://developer.fastspring.com
  baseURL: https://api.fastspring.com
  tags:
  - Event
  tags_raw:
  - Events
  properties:
  - type: OpenAPI
    url: openapi/fastspring-events-api-openapi.yml
  - type: Documentation
    url: https://developer.fastspring.com/reference
  - type: GettingStarted
    url: https://developer.fastspring.com/reference/getting-started-with-your-api
  - type: Authentication
    url: https://developer.fastspring.com/reference/authentication
  - type: Webhooks
    url: https://developer.fastspring.com/reference/webhooks
  - type: Message Security
    url: https://developer.fastspring.com/reference/message-security
  - type: AsyncAPI
    url: https://raw.githubusercontent.com/api-evangelist/fastspring/refs/heads/main/asyncapi/fastspring-asyncapi.yml
- aid: fastspring:fastspring-invoices-api
  name: FastSpring Invoices API
  description: The Invoices API from FastSpring — 2 operation(s) for invoices.
  humanURL: https://developer.fastspring.com
  baseURL: https://api.fastspring.com
  tags:
  - Invoices
  properties:
  - type: OpenAPI
    url: openapi/fastspring-invoices-api-openapi.yml
  - type: Documentation
    url: https://developer.fastspring.com/reference
  - type: GettingStarted
    url: https://developer.fastspring.com/reference/getting-started-with-your-api
  - type: Authentication
    url: https://developer.fastspring.com/reference/authentication
  - type: Webhooks
    url: https://developer.fastspring.com/reference/webhooks
  - type: Message Security
    url: https://developer.fastspring.com/reference/message-security
  - type: AsyncAPI
    url: https://raw.githubusercontent.com/api-evangelist/fastspring/refs/heads/main/asyncapi/fastspring-asyncapi.yml
- aid: fastspring:fastspring-orders-api
  name: FastSpring Orders API
  description: The Orders API from FastSpring — 2 operation(s) for orders.
  humanURL: https://developer.fastspring.com
  baseURL: https://api.fastspring.com
  tags:
  - Order
  tags_raw:
  - Orders
  properties:
  - type: OpenAPI
    url: openapi/fastspring-orders-api-openapi.yml
  - type: Documentation
    url: https://developer.fastspring.com/reference
  - type: GettingStarted
    url: https://developer.fastspring.com/reference/getting-started-with-your-api
  - type: Authentication
    url: https://developer.fastspring.com/reference/authentication
  - type: Webhooks
    url: https://developer.fastspring.com/reference/webhooks
  - type: Message Security
    url: https://developer.fastspring.com/reference/message-security
  - type: AsyncAPI
    url: https://raw.githubusercontent.com/api-evangelist/fastspring/refs/heads/main/asyncapi/fastspring-asyncapi.yml
- aid: fastspring:fastspring-products-api
  name: FastSpring Products API
  description: The Products API from FastSpring — 3 operation(s) for products.
  humanURL: https://developer.fastspring.com
  baseURL: https://api.fastspring.com
  tags:
  - Product
  tags_raw:
  - Products
  properties:
  - type: OpenAPI
    url: openapi/fastspring-products-api-openapi.yml
  - type: Documentation
    url: https://developer.fastspring.com/reference
  - type: GettingStarted
    url: https://developer.fastspring.com/reference/getting-started-with-your-api
  - type: Authentication
    url: https://developer.fastspring.com/reference/authentication
  - type: Webhooks
    url: https://developer.fastspring.com/reference/webhooks
  - type: Message Security
    url: https://developer.fastspring.com/reference/message-security
  - type: AsyncAPI
    url: https://raw.githubusercontent.com/api-evangelist/fastspring/refs/heads/main/asyncapi/fastspring-asyncapi.yml
- aid: fastspring:fastspring-quotes-api
  name: FastSpring Quotes API
  description: The Quotes API from FastSpring — 3 operation(s) for quotes.
  humanURL: https://developer.fastspring.com
  baseURL: https://api.fastspring.com
  tags:
  - Quotes
  properties:
  - type: OpenAPI
    url: openapi/fastspring-quotes-api-openapi.yml
  - type: Documentation
    url: https://developer.fastspring.com/reference
  - type: GettingStarted
    url: https://developer.fastspring.com/reference/getting-started-with-your-api
  - type: Authentication
    url: https://developer.fastspring.com/reference/authentication
  - type: Webhooks
    url: https://developer.fastspring.com/reference/webhooks
  - type: Message Security
    url: https://developer.fastspring.com/reference/message-security
  - type: AsyncAPI
    url: https://raw.githubusercontent.com/api-evangelist/fastspring/refs/heads/main/asyncapi/fastspring-asyncapi.yml
- aid: fastspring:fastspring-returns-api
  name: FastSpring Returns API
  description: The Returns API from FastSpring — 2 operation(s) for returns.
  humanURL: https://developer.fastspring.com
  baseURL: https://api.fastspring.com
  tags:
  - Returns
  properties:
  - type: OpenAPI
    url: openapi/fastspring-returns-api-openapi.yml
  - type: Documentation
    url: https://developer.fastspring.com/reference
  - type: GettingStarted
    url: https://developer.fastspring.com/reference/getting-started-with-your-api
  - type: Authentication
    url: https://developer.fastspring.com/reference/authentication
  - type: Webhooks
    url: https://developer.fastspring.com/reference/webhooks
  - type: Message Security
    url: https://developer.fastspring.com/reference/message-security
  - type: AsyncAPI
    url: https://raw.githubusercontent.com/api-evangelist/fastspring/refs/heads/main/asyncapi/fastspring-asyncapi.yml
- aid: fastspring:fastspring-sessions-api
  name: FastSpring Sessions API
  description: The Sessions API from FastSpring — 5 operation(s) for sessions.
  humanURL: https://developer.fastspring.com
  baseURL: https://api.fastspring.com
  tags:
  - Sessions
  properties:
  - type: OpenAPI
    url: openapi/fastspring-sessions-api-openapi.yml
  - type: Documentation
    url: https://developer.fastspring.com/reference
  - type: GettingStarted
    url: https://developer.fastspring.com/reference/getting-started-with-your-api
  - type: Authentication
    url: https://developer.fastspring.com/reference/authentication
  - type: Webhooks
    url: https://developer.fastspring.com/reference/webhooks
  - type: Message Security
    url: https://developer.fastspring.com/reference/message-security
  - type: AsyncAPI
    url: https://raw.githubusercontent.com/api-evangelist/fastspring/refs/heads/main/asyncapi/fastspring-asyncapi.yml
- aid: fastspring:fastspring-subscriptions-api
  name: FastSpring Subscriptions API
  description: The Subscriptions API from FastSpring — 7 operation(s) for subscriptions.
  humanURL: https://developer.fastspring.com
  baseURL: https://api.fastspring.com
  tags:
  - Subscription
  tags_raw:
  - Subscriptions
  properties:
  - type: OpenAPI
    url: openapi/fastspring-subscriptions-api-openapi.yml
  - type: Documentation
    url: https://developer.fastspring.com/reference
  - type: GettingStarted
    url: https://developer.fastspring.com/reference/getting-started-with-your-api
  - type: Authentication
    url: https://developer.fastspring.com/reference/authentication
  - type: Webhooks
    url: https://developer.fastspring.com/reference/webhooks
  - type: Message Security
    url: https://developer.fastspring.com/reference/message-security
  - type: AsyncAPI
    url: https://raw.githubusercontent.com/api-evangelist/fastspring/refs/heads/main/asyncapi/fastspring-asyncapi.yml
- aid: fastspring:fastspring-webhooks-api
  name: FastSpring Webhooks API
  description: The Webhooks API from FastSpring — 1 operation(s) for webhooks.
  humanURL: https://developer.fastspring.com
  baseURL: https://api.fastspring.com
  tags:
  - Webhook
  tags_raw:
  - Webhooks
  properties:
  - type: OpenAPI
    url: openapi/fastspring-webhooks-api-openapi.yml
  - type: Documentation
    url: https://developer.fastspring.com/reference
  - type: GettingStarted
    url: https://developer.fastspring.com/reference/getting-started-with-your-api
  - type: Authentication
    url: https://developer.fastspring.com/reference/authentication
  - type: Webhooks
    url: https://developer.fastspring.com/reference/webhooks
  - type: Message Security
    url: https://developer.fastspring.com/reference/message-security
  - type: AsyncAPI
    url: https://raw.githubusercontent.com/api-evangelist/fastspring/refs/heads/main/asyncapi/fastspring-asyncapi.yml
common:
- type: AgenticAccess
  url: agentic-access/fastspring-agentic-access.yml
- type: TrustCenter
  url: security/fastspring-trust-center.yml
- type: DomainSecurity
  url: security/fastspring-domain-security.yml
- type: Authentication
  url: authentication/fastspring-authentication.yml
- type: GitHubOrganization
  url: https://github.com/FastSpring
- type: LinkedIn
  url: https://www.linkedin.com/company/fastspring
- type: Website
  url: https://fastspring.com
- type: Documentation
  url: https://developer.fastspring.com
- type: Pricing
  url: https://fastspring.com/pricing
- type: Signup
  url: https://fastspring.com/contact-sales
- type: App Dashboard
  url: https://app.fastspring.com
- type: Support
  url: https://fastspring.com/support
- type: LlmsText
  url: https://developer.fastspring.com/llms.txt
- url: https://fastspring.com/blog/feed/
  type: Blog
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com