GPTZero

GPTZero is an AI content detection company whose v2 API analyzes text and uploaded documents to determine whether content was written by a human, by AI, or is a mix of both. The API returns document-, paragraph-, and sentence-level probabilities along with supporting perplexity and burstiness signals, plus asynchronous batch analysis and aggregate reporting. Authentication is via an X-API-Key header, requests are rate limited to 30,000 per hour, and API access is bundled with the Professional plan. GPTZero was surfaced as a portfolio company of Uncork Capital and has been enriched into the API Evangelist network from its public developer surface.

GPTZero publishes 3 API contracts indexed on the APIs.io network: Batch API, Detection API, and Documents API. Tagged areas include Company, Artificial Intelligence, AI Detection, Content Moderation, and Machine Learning.

GPTZero’s developer surface includes engineering blog, documentation, API reference, getting-started guide, support, pricing, signup flow, and 25 more developer resources.

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53.7/100 developing ▬ flat Agent 22/100 agent aware Front door AI 6/6 dominant saas Full breakdown ↓
scored 2026-10-31 · rubric v0.25.0 · Show this score on your site →

AccessFreemiumSelf serve⚡ Free to try

1 published contract 2 Agent Skills

Company Artificial Intelligence AI Detection Content Moderation Machine Learning Text Analysis Natural Language Processing Education

Kin Score

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

Composite quality — 53.7/100 · developing

Contract Quality 8.8 / 21

Developer Ergonomics 11.2 / 17

Access Clarity 14.3 / 17

Operational Transparency 4.7 / 11

Contract Governance 0.5 / 10

Discoverability 5.6 / 9

Regulatory Posture 3.4 / 15

Agent readiness — 22/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

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 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 0 / 5

Distinct Operations 3 / 3

Regulatory Posture applies to this provider. Its tags matched the Education & Research 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):

MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
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
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes
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)

9 more unmet checks in the Agent Readiness table above.

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

Contract Quality scores 41.6 — up to +14.6 composite points
Contract Governance scores 4.5 — up to +11.5 composite points
Operational Transparency scores 42.1 — up to +7.5 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/gptzero/apis.yml: open an issue on github.com/api-evangelist/gptzero 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 →

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
Browser Extension Stores (company-published Firefox add-ons; Chrome Web Store unreadable)	builds-on	29.6	-	-

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 3

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

GPTZero Batch API

Batch processing

GPTZero Detection API

AI content detection

GPTZero Documents API

Document analysis

Open Collections 3

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

GPTZero Batch API

OPEN COLLECTION

GPTZero Batch Detection API

OPEN COLLECTION

GPTZero Batch Documents API

OPEN COLLECTION

Agent Skills 2

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

Run a batch AI-detection job with GPTZero

AGENT SKILL

Detect AI-generated text with GPTZero

AGENT SKILL

Pricing Plans 2

Published pricing tiers and plan structures.

Gptzero Plans

4 plans

PLANS

Gptzero Price Estimates

0 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Gptzero Rate Limits

1 limits

RATE LIMITS

FinOps 1

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

Gptzero Finops

FINOPS

OpenAPI Overlays 1

Overlays applied on top of this provider's contracts. Each card says who wrote it: a document the provider publishes, or one API Evangelist derived or generated.

Gptzero Openapi Overlay

3 actions · update · gptzero-openapi-original.json

DERIVED

Security Posture 2

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

Gptzero Authentication

apiKey · 1 scheme

SECURITY

Gptzero Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Agentic Access 1

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

Gptzero Agentic Access

7 operations · 3 acting

AGENTIC

Resources

Get Started 3

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

GettingStarted

GettingStarted

SignUp

SignUp

Documentation 3

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

OpenAPI

OpenAPI

Agent Surfaces 5

MCP servers, agent skills, and machine-readable catalogs

X-MCPServerCandidate

AgentSkill

AgentSkill

LLMsTxt

AgenticAccess

Design & Contract 4

Pagination, idempotency, versioning, errors, and events

Conformance

Conventions

Lifecycle

DataModel

Build 3

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

Packages

Packages

SDKs

SDKs

Access & Security 2

Authentication, authorization, and security posture

Authentication

Authentication

DomainSecurity

DomainSecurity

Operate 3

Status, limits, changes, and where to get help

Support

Support

ChangeLog

ChangeLog

RateLimits

RateLimits

Commercial 4

Pricing, plans, and the legal terms of use

Pricing

TermsOfService

PrivacyPolicy

Plans

Company 4

The organization behind the API

Blog

BlogRSS

Website

Blog

Other 1

Properties that don't map to a standard resource type

Overlay

Overlay

Source (apis.yml)

aid: gptzero
name: GPTZero
description: GPTZero is an AI content detection company whose v2 API analyzes text and uploaded documents to determine whether
  content was written by a human, by AI, or is a mix of both. The API returns document-, paragraph-, and sentence-level probabilities
  along with supporting perplexity and burstiness signals, plus asynchronous batch analysis and aggregate reporting. Authentication
  is via an X-API-Key header, requests are rate limited to 30,000 per hour, and API access is bundled with the Professional
  plan. GPTZero was surfaced as a portfolio company of Uncork Capital and has been enriched into the API Evangelist network
  from its public developer surface.
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: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Freemium · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  - rate-limits
  - security
  generated: '2026-09-03'
  method: derived
image: https://gptzero.me/logo.png
url: https://raw.githubusercontent.com/api-evangelist/gptzero/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- uncork-capital
x-tier: stub
x-tier-reason: portfolio-lead
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-10-06'
tags:
- Company
- Artificial Intelligence
- AI Detection
- Content Moderation
- Machine Learning
- Text Analysis
- Natural Language Processing
- Education
tags_raw:
- Company
- Ai
- AI Detection
- Content Moderation
- Machine Learning
- Text Analysis
- Natural Language Processing
- Education
- Machine-Learning
apis:
- aid: gptzero:gptzero-batch-api
  name: GPTZero Batch API
  description: Batch processing
  humanURL: https://gptzero.stoplight.io/
  baseURL: https://api.gptzero.me/v2
  tags:
  - Batch
  properties:
  - type: OpenAPI
    url: openapi/gptzero-batch-api-openapi.yml
  - type: APIReference
    url: https://gptzero.stoplight.io/docs/gptzero-api/5bf295g49gwxp-gpt-zero-api
- aid: gptzero:gptzero-detection-api
  name: GPTZero Detection API
  description: AI content detection
  humanURL: https://gptzero.stoplight.io/
  baseURL: https://api.gptzero.me/v2
  tags:
  - Detection
  properties:
  - type: OpenAPI
    url: openapi/gptzero-detection-api-openapi.yml
  - type: APIReference
    url: https://gptzero.stoplight.io/docs/gptzero-api/5bf295g49gwxp-gpt-zero-api
- aid: gptzero:gptzero-documents-api
  name: GPTZero Documents API
  description: Document analysis
  humanURL: https://gptzero.stoplight.io/
  baseURL: https://api.gptzero.me/v2
  tags:
  - Documents
  properties:
  - type: OpenAPI
    url: openapi/gptzero-documents-api-openapi.yml
  - type: APIReference
    url: https://gptzero.stoplight.io/docs/gptzero-api/5bf295g49gwxp-gpt-zero-api
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- url: https://gptzero.me/news/
  type: Blog
- url: https://gptzero.me/news/rss/
  type: BlogRSS
- type: Website
  url: https://gptzero.me
- type: DeveloperPortal
  url: https://gptzero.me/developers
- type: Documentation
  url: https://gptzero.stoplight.io/
- type: APIReference
  url: https://gptzero.stoplight.io/docs/gptzero-api/5bf295g49gwxp-gpt-zero-api
- type: GettingStarted
  url: https://support.gptzero.me/hc/en-us/articles/15525014408215-How-can-I-get-the-API-and-request-code-samples
- type: Support
  url: https://support.gptzero.me
- type: Blog
  url: https://gptzero.me/news
- type: GitHubOrganization
  url: https://github.com/GPTZero
- type: Pricing
  url: https://gptzero.me/pricing
- type: SignUp
  url: https://app.gptzero.me/login
- type: TermsOfService
  url: https://gptzero.me/terms-of-use.html
- type: PrivacyPolicy
  url: https://gptzero.me/privacy-policy.html
- type: Integrations
  url: https://gptzero.me/integrations
- type: OpenAPI
  url: openapi/_original/gptzero-openapi-original.json
- type: Authentication
  url: authentication/gptzero-authentication.yml
- type: Packages
  url: packages/gptzero-packages.yml
- type: SDKs
  url: packages/gptzero-packages.yml
- type: X-MCPServerCandidate
  url: mcp/gptzero-mcp.yml
  note: 'Renamed from MCPServer 2026-09-03 (roadmap#247): the manifest self-describes as status: candidate — a tool list derived
    from the published API contracts, not an existing server. The scorer already read the manifest and reported mcp_server
    correctly; the MCPServer type was crediting the artifact-type surfaces with a server that does not exist.'
- type: AgentSkill
  url: skills/gptzero-detect-ai-text.md
- type: AgentSkill
  url: skills/gptzero-batch-analysis.md
- type: LLMsTxt
  url: llms/gptzero-llms.txt
- type: Overlay
  url: overlays/gptzero-openapi-overlay.yaml
- type: Conformance
  url: conformance/gptzero-conformance.yml
- type: Conventions
  url: conventions/gptzero-conventions.yml
- type: Lifecycle
  url: lifecycle/gptzero-lifecycle.yml
- type: ChangeLog
  url: changelog/gptzero-changelog.yml
- type: DataModel
  url: data-model/gptzero-data-model.yml
- type: RateLimits
  url: rate-limits/gptzero-rate-limits.yml
- type: Plans
  url: plans/gptzero-plans.yml
- type: DomainSecurity
  url: security/gptzero-domain-security.yml
- type: AgenticAccess
  url: agentic-access/gptzero-agentic-access.yml
x-enrichment:
  date: '2026-07-19'
  status: backfilled
  pass: local-v1
  note: backfilled from .gitignore signal + verified work evidence

GPTZero API — frequently asked questions

Does GPTZero have an API?

Yes. APIs.io lists 3 APIs from GPTZero, including GPTZero Batch API, GPTZero Detection API and GPTZero Documents API.

Is there an OpenAPI specification for the GPTZero API?

Yes. APIs.io indexes 3 OpenAPI specifications for GPTZero, each linked for download from this page.

How do I authenticate with the GPTZero API?

GPTZero uses bearer-token authentication (apiKey · 1 scheme). The details are profiled on APIs.io as Gptzero Authentication.

How much does the GPTZero API cost?

APIs.io lists 4 pricing plans for GPTZero, with each plan's price, limits and inclusions under Pricing Plans on this page.

Is the GPTZero API ready for AI agents?

GPTZero has a Kin Score of 53.7 out of 100 (developing) and an Agent Readiness score of 21.6 (agent-aware), scored by API Evangelist on 2026-10-31.

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