gumballtools-com

Project Gumball is an open‑source experiment that aggregates a collection of small utility tools into a single MCP (Multi‑Capability Provider) endpoint. The platform offers a directory of fifteen tools, each accessible via a web page, a JSON API, and an MCP server, allowing agents to discover, call, and pay for capabilities in a unified way. It showcases how agents can find each other, agree on value, and record usage metrics, providing transparent insight into tool usage and integration patterns across the ecosystem.

gumballtools-com is listed with 4 APIs on the APIs.io network, including Project Gumball, and 3 more. Tagged areas include Company, API, MCP, Tools, and OpenSource.

The gumballtools-com catalog on APIs.io includes 1 Spectral governance ruleset.

gumballtools-com’s developer surface includes changelog, documentation, API reference, getting-started guide, and 15 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

33.9/100 thin Agent 27/100 agent aware Full breakdown ↓
scored 2026-10-31 · rubric v0.25.0 · Show this score on your site →

4 APIs 1 MCP Servers 1 Agent Skills

CompanyAPIMCP ToolsOpenSource

Kin Score

Kin Score How this is scored →
scored 2026-10-31 · rubric v0.25.0

Composite quality — 33.9/100 · thin

Contract Quality 5.1 / 21

Developer Ergonomics 7.6 / 17

Access Clarity 3.6 / 17

Operational Transparency 4.1 / 11

Contract Governance 1.9 / 10

Discoverability 6.0 / 9

Regulatory Posture 3.1 / 15

Agent readiness — 27/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 12 / 12

Machine-Readable Auth 0 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 5 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 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 Horizontal (data, software, accessibility, platform) 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 could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

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/.

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Agent readiness — checks not met, largest first (exact, from this profile):

Machine-Readable Auth +10 pts — a served openid-configuration/oauth-authorization-server carrying `issuer` (served), else the securitySchemes class in the provider OpenAPIs — bound (mutualTLS, DPoP, Signature) > negotiable (oauth2 authorizationCode/clientCredentials, openIdConnect) > bearer (http bearer, apiKey)
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Request/Response Examples +7 pts — share of operations carrying request/response examples; else an Examples / Code Samples link
Delegated User Identity +6 pts — a served discovery document listing authorization_code in grant_types_supported (served), else an oauth2 authorizationCode flow or openIdConnect declared in an OpenAPI (documented)
Registration Without a Human +6 pts — a `registration_endpoint` in the served RFC 8414 / OIDC discovery document

7 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Contract Quality scores 24.0 — up to +19.0 composite points
Access Clarity scores 21.1 — up to +15.8 composite points
Developer Ergonomics scores 44.5 — up to +11.1 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

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 the provider profile at artifacts.apis.io/gumballtools-com/apis.yml: open an issue on github.com/api-evangelist/gumballtools-com to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 4

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

Project Gumball

A directory of the Gumball tools, a live view of who is calling them, and a single MCP server that exposes every tool in the portfolio.

Amortization Schedule

Builds a full period-by-period amortization schedule — principal, interest, PMI, extra-principal, running balance — for monthly or daily-accrual loans.

Body Metrics

Convert height and weight in any common unit, then compute BMI, resting and total energy expenditure, and protein targets.

Check Digit Validator

Validates IBAN, ISBN, EAN/UPC and card numbers, and suggests corrections for invalid inputs.

MCP Servers 1

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

gumballtools-com MCP Server

Remote MCP server at gumballtools.com.

MCP SERVER

Agent Skills 1

Packaged agent skills for driving this provider's APIs from an AI assistant.

list-tools

AGENT SKILL

Pricing Plans 1

Published pricing tiers and plan structures.

Gumballtools Com Plans Pricing

1 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Gumballtools Com Rate Limits

1 limits

RATE LIMITS

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

gumballtools-com API Rules

13 rules · 11 errors 1 warnings 1 info

SPECTRAL

Security Posture 2

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

Gumballtools Com Authentication

1 scheme

SECURITY

Gumballtools Com Domain Security

TLSv1.3 · HSTS

SECURITY

Scopes 1

OAuth scopes governing access to this provider's APIs.

Gumballtools Com Scopes

OAuth 2.0 · no documented scopes

0 scopes

SCOPES

Agentic Access 1

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

Gumballtools Com Agentic Access

4 operations

4 operations · 0 acting

AGENTIC

Resources

Get Started 2

Portal, sign-up, and the first successful call

GettingStarted

GettingStarted

DeveloperPortal

DeveloperPortal

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgentSkill

LLMsTxt

MCPServer

Design & Contract 4

Pagination, idempotency, versioning, errors, and events

Spectral

Lifecycle

ErrorCatalog

Conformance

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Operate 2

Status, limits, changes, and where to get help

RateLimits

RateLimits

ChangeLog

ChangeLog

Commercial 1

Pricing, plans, and the legal terms of use

Plans

Plans

Company 1

The organization behind the API

Website

Website

Other 2

Properties that don't map to a standard resource type

Hosts

Hosts

Vendors

Vendors

Source (apis.yml)

aid: gumballtools-com
name: gumballtools-com
description: Project Gumball is an open‑source experiment that aggregates a collection of small utility tools into a single
  MCP (Multi‑Capability Provider) endpoint. The platform offers a directory of fifteen tools, each accessible via a web page,
  a JSON API, and an MCP server, allowing agents to discover, call, and pay for capabilities in a unified way. It showcases
  how agents can find each other, agree on value, and record usage metrics, providing transparent insight into tool usage
  and integration patterns across the ecosystem.
url: https://artifacts.apis.io/gumballtools-com/apis.yml
x-type: company
x-source: harvest:mcp-registry
x-tier: profiled
x-tier-reason: enrichment pass 2026-10-29 (modular-v1; was harvest)
specificationVersion: '0.20'
created: '2026-10-29'
modified: '2026-10-29'
tags:
- Company
- API
- MCP
- Tools
- OpenSource
image: https://via.placeholder.com/300
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: AgenticAccess
  url: agentic-access/gumballtools-com-agentic-access.yml
- type: RateLimits
  url: rate-limits/gumballtools-com-rate-limits.yml
- type: Plans
  url: plans/gumballtools-com-plans-pricing.yml
- type: Spectral
  url: rules/gumballtools-com-rules.yml
- type: AgentSkill
  url: skills/_index.yml
- type: ChangeLog
  url: changelog/gumballtools-com-changelog.yml
- type: Lifecycle
  url: lifecycle/gumballtools-com-lifecycle.yml
- type: ErrorCatalog
  url: errors/gumballtools-com-problem-types.yml
- type: Conformance
  url: conformance/gumballtools-com-conformance.yml
- type: LLMsTxt
  url: llms/gumballtools-com-llms.txt
- type: MCPServer
  url: mcp/gumballtools-com-mcp.yml
- type: Hosts
  url: hosts/gumballtools-com-hosts.yml
- type: Vendors
  url: vendors/gumballtools-com-vendors.yml
- type: DomainSecurity
  url: security/gumballtools-com-domain-security.yml
- type: Website
  url: https://gumballtools.com/
- type: Documentation
  url: https://gumballtools.com/docs
- type: APIReference
  url: https://gumballtools.com/.well-known/openapi.json
- type: GettingStarted
  url: https://gumballtools.com/docs
- type: DeveloperPortal
  url: https://gumballtools.com/docs
apis:
- name: Project Gumball
  description: A directory of the Gumball tools, a live view of who is calling them, and a single MCP server that exposes
    every tool in the portfolio.
  humanURL: https://gumballtools.com/docs
  baseURL: https://gumballtools.com
  properties:
  - type: OpenAPI
    url: https://gumballtools.com/.well-known/openapi.json
  aid: gumballtools-com:project-gumball
- name: Amortization Schedule
  description: Builds a full period-by-period amortization schedule — principal, interest, PMI, extra-principal, running balance
    — for monthly or daily-accrual loans.
  humanURL: https://amortize.gumballtools.com
  baseURL: https://amortize.gumballtools.com
  aid: gumballtools-com:amortization-schedule
- name: Body Metrics
  description: Convert height and weight in any common unit, then compute BMI, resting and total energy expenditure, and protein
    targets.
  humanURL: https://body-metrics.gumballtools.com
  baseURL: https://body-metrics.gumballtools.com
  aid: gumballtools-com:body-metrics
- name: Check Digit Validator
  description: Validates IBAN, ISBN, EAN/UPC and card numbers, and suggests corrections for invalid inputs.
  humanURL: https://check-digit.gumballtools.com
  baseURL: https://check-digit.gumballtools.com
  aid: gumballtools-com:check-digit-validator
x-enrichment:
  date: '2026-10-29'
  status: enriched
  artifacts_added: 27
  pass: modular-v1
  engine: identity=oss,contract=oss,surfaces=oss,docs=oss,regulatory=oss

gumballtools-com API — frequently asked questions

Does gumballtools-com have an API?

Yes. APIs.io lists 4 APIs from gumballtools-com, including Project Gumball, Amortization Schedule and Body Metrics, and 1 more.

Is there an OpenAPI specification for the gumballtools-com API?

Yes. APIs.io indexes 1 OpenAPI specification for gumballtools-com, each linked for download from this page.

How do I authenticate with the gumballtools-com API?

gumballtools-com documents its authentication (1 scheme). The details are profiled on APIs.io as Gumballtools Com Authentication.

How much does the gumballtools-com API cost?

APIs.io lists 1 pricing plan for gumballtools-com, with each plan's price, limits and inclusions under Pricing Plans on this page.

Does gumballtools-com have an MCP server?

Yes. APIs.io lists 1 MCP server for gumballtools-com: Remote MCP server at gumballtools.com.

Is the gumballtools-com API ready for AI agents?

gumballtools-com has a Kin Score of 33.9 out of 100 (thin) and an Agent Readiness score of 26.8 (agent-aware), scored by API Evangelist on 2026-10-31.

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