Zeffy

Zeffy is a 100% free fundraising platform for nonprofits - donation forms, event ticketing, peer-to-peer campaigns, memberships, e-commerce, and donor management - with no platform, transaction, or credit-card fees, funded entirely by optional tips from donors. Zeffy exposes a free public REST API that gives organization admins read-only access to their Payments, Contacts, and Campaigns data (base https://api.zeffy.com/api/v1), authenticated with a per-organization API key sent as a Bearer token, plus outbound webhooks that POST payment details to a configured URL when a payment is completed. Zeffy also integrates via Zapier, QuickBooks, and WordPress.

Zeffy publishes 3 APIs on the APIs.io network: Campaigns API, Contacts API, and Payments API. Tagged areas include Fundraising, Nonprofit, Donations, Payments, and Donor Management.

Zeffy’s developer surface includes authentication, documentation, engineering blog, and 7 more developer resources.

🌐 Visit website 📡 Source on GitHub

33.6/100 thin ▬ flat Agent 31/100 agent aware Full breakdown ↓
scored 2026-08-05 · rubric v0.9.1

AccessFreeSelf serve⚡ Free to try

4 APIs

FundraisingNonprofitDonationsPaymentsDonor ManagementFreeWebhooks

Kin Score

Kin Score How this is scored →
scored 2026-08-05 · rubric v0.9.1

Composite quality — 33.6/100 · thin

Contract Quality 15.9 / 25

Developer Ergonomics 4.3 / 20

Commercial Clarity 5.8 / 20

Operational Transparency 2.7 / 13

Governance 0.0 / 12

Discoverability 7.4 / 10

Agent readiness — 31/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

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 7 / 7

Typed Event Surface 0 / 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

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/zeffy: 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 4

Individual APIs this provider publishes, each with its own machine-readable definition.

Rate Limits 1

Documented rate limits and quota policies.

Zeffy Rate Limits

1 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

AGENTIC

Resources

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

Operate 1

Status, limits, changes, and where to get help

RateLimits

RateLimits

Commercial 2

Pricing, plans, and the legal terms of use

Plans

Plans

FinOps

FinOps

Company 3

The organization behind the API

LinkedIn

Website

Website

Blog

Blog

Source (apis.yml)

aid: zeffy
url: https://raw.githubusercontent.com/api-evangelist/zeffy/refs/heads/main/apis.yml
name: Zeffy
kind: company
description: Zeffy is a 100% free fundraising platform for nonprofits - donation forms, event ticketing, peer-to-peer campaigns,
  memberships, e-commerce, and donor management - with no platform, transaction, or credit-card fees, funded entirely by optional
  tips from donors. Zeffy exposes a free public REST API that gives organization admins read-only access to their Payments,
  Contacts, and Campaigns data (base https://api.zeffy.com/api/v1), authenticated with a per-organization API key sent as
  a Bearer token, plus outbound webhooks that POST payment details to a configured URL when a payment is completed. Zeffy
  also integrates via Zapier, QuickBooks, and WordPress.
accessModel:
  pricing: free
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Free · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/zeffy.png
tags:
- Fundraising
- Nonprofit
- Donations
- Payments
- Donor Management
- Free
- Webhooks
created: '2026-07-05'
modified: '2026-07-05'
specificationVersion: '0.19'
apis:
- aid: zeffy:zeffy-webhooks
  name: Zeffy Webhooks
  tags:
  - Webhooks
  - Events
  - Payments
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://support.zeffy.com/get-started-with-the-zeffy-api-yourg
  baseURL: https://api.zeffy.com/api/v1
  properties:
  - url: https://www.zeffy.com/integration/api
    type: Documentation
  - url: https://support.zeffy.com/get-started-with-the-zeffy-api-yourg
    type: APIReference
  description: Outbound webhooks configured under Settings then Integrations. When a payment is completed, Zeffy sends an
    HTTP POST with the full payment details to the organization's configured URL, enabling thank-you workflows, CRM/accounting
    sync, and internal notifications. This is Zeffy-to-consumer HTTP notification, not an inbound API surface.
- aid: zeffy:zeffy-campaigns-api
  name: Zeffy Campaigns API
  description: Donation forms, events, and other campaign types.
  humanURL: https://support.zeffy.com/get-started-with-the-zeffy-api-yourg
  baseURL: https://api.zeffy.com/api/v1
  tags:
  - Campaigns
  properties:
  - type: OpenAPI
    url: openapi/zeffy-campaigns-api-openapi.yml
  - type: Documentation
    url: https://www.zeffy.com/integration/api
  - type: APIReference
    url: https://support.zeffy.com/get-started-with-the-zeffy-api-yourg
- aid: zeffy:zeffy-contacts-api
  name: Zeffy Contacts API
  description: An organization's donors and supporters.
  humanURL: https://support.zeffy.com/get-started-with-the-zeffy-api-yourg
  baseURL: https://api.zeffy.com/api/v1
  tags:
  - Contacts
  properties:
  - type: OpenAPI
    url: openapi/zeffy-contacts-api-openapi.yml
  - type: Documentation
    url: https://www.zeffy.com/integration/api
  - type: APIReference
    url: https://support.zeffy.com/get-started-with-the-zeffy-api-yourg
- aid: zeffy:zeffy-payments-api
  name: Zeffy Payments API
  description: An organization's transactions and donations.
  humanURL: https://support.zeffy.com/get-started-with-the-zeffy-api-yourg
  baseURL: https://api.zeffy.com/api/v1
  tags:
  - Payments
  properties:
  - type: OpenAPI
    url: openapi/zeffy-payments-api-openapi.yml
  - type: Documentation
    url: https://www.zeffy.com/integration/api
  - type: APIReference
    url: https://support.zeffy.com/get-started-with-the-zeffy-api-yourg
common:
- type: AgenticAccess
  url: agentic-access/zeffy-agentic-access.yml
- type: DomainSecurity
  url: security/zeffy-domain-security.yml
- type: Authentication
  url: authentication/zeffy-authentication.yml
- type: LinkedIn
  url: https://www.linkedin.com/company/zeffy
- type: Website
  url: https://www.zeffy.com
- type: Documentation
  url: https://www.zeffy.com/integration/api
- type: Plans
  url: plans/zeffy-plans-pricing.yml
- type: RateLimits
  url: rate-limits/zeffy-rate-limits.yml
- type: FinOps
  url: finops/zeffy-finops.yml
- type: Blog
  url: https://www.zeffy.com/blog
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

Zeffy

Kin Score

APIs 4

Zeffy Webhooks

Zeffy Campaigns API

Zeffy Contacts API

Zeffy Payments API

Pricing Plans 1

Zeffy Plans Pricing

Rate Limits 1

Zeffy Rate Limits

FinOps 1

Zeffy Finops

Security Posture 2

Zeffy Authentication

Zeffy Domain Security

Agentic Access 1

Zeffy Agentic Access