Overflow
Overflow is a fintech giving platform for churches and nonprofits that lets organizations accept and reconcile donations across many asset types — card and ACH, Apple Pay and Google Pay, stock, cryptocurrency, RoundUps, and Donor Advised Funds (DAFs) — through a single unified platform. Overflow also offers Overflow Tap (NFC tap-to-give hardware) and Generosity University donor education. Its public Overflow Open API (v3) is a REST interface over contributions, donors, subscriptions (recurring gifts), payments, campaigns, deposits, refunds, chargebacks, locations, tap devices/events, and webhooks, authenticated with header API keys and used to sync giving data into CRMs and accounting/reconciliation workflows. Overflow is backed by Uncork Capital.
Real signal across most facets with visible, nameable gaps — the contract exists but is thin, or the portal is good while governance and commercial terms are absent.
API Evangelist profiles Overflow the way a machine reads it — 18 machine-readable artifacts across 13 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 — Overflow scores 51.9/100 (developing), with a separate agent-readiness read of 78/100 (agent native). 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 Overflow
Each block below is one kind of artifact we hold for Overflow. 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 13
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.
Overflow Campaigns API
The Campaigns API from Overflow — 2 operation(s) for campaigns.
Overflow Chargebacks API
The Chargebacks API from Overflow — 2 operation(s) for chargebacks.
Overflow Contributions API
The Contributions API from Overflow — 3 operation(s) for contributions.
Overflow Deposits API
The Deposits API from Overflow — 3 operation(s) for deposits.
Overflow Donors API
The Donors API from Overflow — 2 operation(s) for donors.
Overflow Locations API
The Locations API from Overflow — 2 operation(s) for locations.
Overflow Payment Methods API
The Payment Methods API from Overflow — 1 operation(s) for payment methods.
Overflow Payments API
The Payments API from Overflow — 1 operation(s) for payments.
Overflow Refunds API
The Refunds API from Overflow — 2 operation(s) for refunds.
Overflow Status API
The Status API from Overflow — 1 operation(s) for status.
Overflow Subscriptions API
The Subscriptions API from Overflow — 3 operation(s) for subscriptions.
Overflow Tap API
The Tap API from Overflow — 7 operation(s) for tap.
Overflow Webhooks API
The Webhooks API from Overflow — 3 operation(s) for webhooks.
Scroll within the panel for all 13 ·
MCP Servers 1
Model Context Protocol servers expose these APIs directly to AI agents. We profile them because agent-native access is the fastest-growing way this provider's capabilities actually get used.
Model Context Protocol servers that expose these APIs to AI agents.
overflow-mcp.yml
MCP SERVEREvent 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.
Overflow Webhooks
ASYNCAPISecurity Posture 2
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 Overflow — 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 5
Portal, sign-up, and the first successful call
Documentation 2
Reference material describing how the API behaves
Agent Surfaces 4
MCP servers, agent skills, and machine-readable catalogs
Design & Contract 6
Pagination, idempotency, versioning, errors, and events
Build 1
SDKs, sample code, and the tooling you integrate with
Access & Security 2
Authentication, authorization, and security posture
Operate 2
Status, limits, changes, and where to get help
Commercial 2
Pricing, plans, and the legal terms of use
Company 1
The organization behind the API
Other 1
Properties that don't map to a standard resource type
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