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, Non-Profit, Donations, Payments, and Donor Management.

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

🌐 Visit website 📡 Source on GitHub

21.6/100 emerging ▼ -10.5 Agent 23/100 agent aware Full breakdown ↓
scored 2026-08-25 · rubric v0.14.0

AccessFreeSelf serve⚡ Free to try

4 APIs

Fundraising Non-Profit Donations Payments Donor Management Free Webhook

Kin Score

Kin Score How this is scored →
scored 2026-08-25 · rubric v0.14.0

Composite quality — 21.6/100 · emerging

Contract Quality 3.0 / 21

Developer Ergonomics 3.6 / 17

Access Clarity 4.9 / 17

Operational Transparency 2.3 / 11

Contract Governance 0.0 / 10

Discoverability 6.3 / 9

Regulatory Posture 2.8 / 15

Agent readiness — 23/100 · 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 9 / 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 4 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Surface 0 / 5

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/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
- Non-Profit
- Donations
- Payments
- Donor Management
- Free
- Webhook
tags_raw:
- Fundraising
- Nonprofit
- Donations
- Payments
- Donor Management
- Free
- Webhooks
created: '2026-07-05'
modified: '2026-07-05'
specificationVersion: '0.23'
apis:
- aid: zeffy:zeffy-webhooks
  name: Zeffy Webhooks
  tags:
  - Webhook
  - Event
  - Payments
  tags_raw:
  - 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

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Zeffy

Kin Score

APIs 4

Zeffy Webhooks

Zeffy Campaigns API

Zeffy Contacts API

Zeffy Payments API

Open Collections 4

API Collection

Zeffy Public Campaigns API

Zeffy Public Campaigns Contacts API

Zeffy Public Campaigns Payments API

Pricing Plans 1

Zeffy Plans Pricing