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 4 API contracts indexed on the APIs.io network, including Campaigns API, Contacts API, Payments API, and 1 more. Tagged areas include Fundraising, Non-Profit, Donations, Payments, and Donor Management.

Zeffy’s developer surface includes authentication, documentation, engineering blog, and 8 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

13.0/100 emerging ▬ flat Agent 53/100 agent ready Front door AI 1/6 silent saas Full breakdown ↓
scored 2026-10-23 · rubric v0.25.0 · Show this score on your site →

AccessFreeSelf serve⚡ Free to try

1 published contract 1 MCP Servers

Fundraising Non-Profit Donations Payments Donor Management Free Webhook

What this lets a business do 1

Business capabilities this provider's published APIs can perform, derived from its own contracts. Browse all capabilities →

Customer Relationship Management

BC-420

Contacts

GET /contacts GET /contacts/{id}

Kin Score

Kin Score How this is scored →
scored 2026-10-23 · rubric v0.25.0

Composite quality — 13.0/100 · emerging

Contract Quality 0.0 / 21

Developer Ergonomics 4.9 / 17

Access Clarity 0.9 / 17

Operational Transparency 0.6 / 11

Contract Governance 0.0 / 10

Discoverability 5.8 / 9

Regulatory Posture 1.6 / 15

Agent readiness — 53/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 6 / 6

MCP Server 12 / 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 6 / 6

Protected Resource Metadata 5 / 5

Registration Without a Human 6 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

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.

Create-or-Update Ergonomics does not apply to this provider. The published contracts declare no write operations, and a read-only API cannot create-or-update. The facet is excluded from this provider's denominator entirely — not scored zero. A reference or data API is not deficient for being unable to upsert.

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/.

Show this score on your site.

It updates itself when the score changes. Paste this where you link to your API docs:

<a href="https://apis.io/providers/zeffy/"><img src="https://apis.io/badge/zeffy/card.svg" alt="Zeffy on APIs.io — Kin Score by API Evangelist"></a>

Other styles, a README pill and a shields.io endpoint are on the badge page.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. 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. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

Market	Position	Depth	Registered MCP server	Declares compatibility
Wix App Market (third-party apps for Wix sites)	undeclared	-	-	-

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

APIs 4

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

Zeffy Webhooks

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 configur...

Zeffy Campaigns API

Donation forms, events, and other campaign types.

Zeffy Contacts API

An organization's donors and supporters.

Zeffy Payments API

An organization's transactions and donations.

Open Collections 3

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

Zeffy Public Campaigns API

OPEN COLLECTION

Zeffy Public Campaigns Contacts API

OPEN COLLECTION

Zeffy Public Campaigns Payments API

OPEN COLLECTION

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

Zeffy MCP Server

Remote MCP server at api.zeffy.com over HTTP.

MCP SERVER

Pricing Plans 1

Published pricing tiers and plan structures.

Zeffy Plans Pricing

1 plans

PLANS

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.

Zeffy Finops

FINOPS

Security Posture 2

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

Zeffy Authentication

http · 1 scheme

SECURITY

Zeffy Domain Security

TLSv1.3 · DNSSEC · DMARC

SECURITY

Agentic Access 1

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

Zeffy Agentic Access

6 operations

6 operations · 0 acting

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

Other 1

Properties that don't map to a standard resource type

CapabilityMap

CapabilityMap

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.
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: high
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: free
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Free · Self-serve signup
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-09-03'
  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: CapabilityMap
  url: capabilities/zeffy-capability-edges.yml
  name: Zeffy Business Capability Map
- 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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