Nekosia is a free, keyless anime-image REST API serving cute anime "neko" (catgirl) imagery and related metadata, backed by the provider's own Booru. Three documented GET operations return JSON carrying dominant colours, original and compressed image variants, dimensions, tags, content ratings, anime and character names, the original source and full artist attribution. No API key, no registration and no account are required; rate limits are enforced per IP address and reported through standards-track RateLimit response headers. Standard public use is free, but commercial use requires prior written consent from the operator.
Nekosia API publishes 1 API on the APIs.io network. Tagged areas include Anime, neko, nekos, neko api, and booru.
Nekosia API’s developer surface includes documentation, API reference, getting-started guide, support, changelog, authentication, code examples, and 25 more developer resources.
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.
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/nekosia: open an issue to ask a question, or submit a pull request to add artifacts.
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Free keyless RESTful JSON API serving random anime/neko images across many categories with rich metadata, a tags endpoint, session mechanism, and content ratings.
aid: nekosia
name: Nekosia API
description: Nekosia is a free, keyless anime-image REST API serving cute anime "neko" (catgirl) imagery and related metadata,
backed by the provider's own Booru. Three documented GET operations return JSON carrying dominant colours, original and
compressed image variants, dimensions, tags, content ratings, anime and character names, the original source and full artist
attribution. No API key, no registration and no account are required; rate limits are enforced per IP address and reported
through standards-track RateLimit response headers. Standard public use is free, but commercial use requires prior written
consent from the operator.
deliveryModel:
model: unknown
open_source: unknown
commercial: true
callable_host: false
label: Delivery model not determined — needs a product licence on record
confidence: low
source:
- pricing
- repository-unlicensed
generated: '2026-08-28'
method: derived
accessModel:
pricing: unknown
onboarding: open
trial: false
try_now: false
public: true
label: Open access
confidence: medium
source:
- authentication
- rate-limits
- security
generated: '2026-09-02'
method: derived
image: https://nekosia.cat/images/og-preview.gif
url: https://raw.githubusercontent.com/api-evangelist/nekosia/refs/heads/main/apis.yml
created: '2026-08-19'
modified: '2026-08-19'
specificationVersion: '0.21'
tags:
- Anime
- neko
- nekos
- neko api
- booru
- Image
- Media
- Entertainment
- Free API
- Open Access
tags_raw:
- anime
- neko
- api
- nekos
- neko api
- booru
- image
- media
- entertainment
- images
- free api
- open access
apis:
- name: Nekosia REST API
description: Free keyless RESTful JSON API serving random anime/neko images across many categories with rich metadata, a
tags endpoint, session mechanism, and content ratings.
humanURL: https://nekosia.cat/documentation?page=introduction
baseURL: https://api.nekosia.cat/api/v1
tags:
- Anime
- neko
- nekos
- neko api
- booru
- Image
- Media
- Entertainment
tags_raw:
- anime
- neko
- api
- nekos
- neko api
- booru
- image
- media
- entertainment
properties:
- type: Documentation
url: https://nekosia.cat/documentation?page=introduction
maintainers:
- FN: Nekosia API
email: support@nekosia.cat
url: https://nekosia.cat/
generated:
by: apis.io/add
model: claude-opus-4-8
confidence: 90
at: '2026-08-19T02:43:46.970Z'
common:
- type: VulnerabilityDisclosure
url: security/nekosia-vulnerability-disclosure.yml
- type: DomainSecurity
url: security/nekosia-domain-security.yml
- type: Security
url: security/nekosia-vulnerability-disclosure.yml
- type: Website
url: https://nekosia.cat/
- type: DeveloperPortal
url: https://nekosia.cat/documentation
- type: Documentation
url: https://nekosia.cat/documentation?page=introduction
- type: APIReference
url: https://nekosia.cat/documentation?page=endpoints
- type: GettingStarted
url: https://nekosia.cat/documentation?page=getting-started
- type: Support
url: https://discord.gg/pba76vJhcP
- type: GitHubOrganization
url: https://github.com/Nekosia-API
- type: Login
url: https://nekosia.cat/login
- type: TermsOfService
url: https://nekosia.cat/documentation?page=tos
- type: PrivacyPolicy
url: https://nekosia.cat/documentation?page=privacy-policy
- type: StatusPage
url: https://status.nekosia.cat
- type: ChangeLog
url: https://nekosia.cat/documentation?page=changelog
- type: ChangeLog
url: changelog/nekosia-changelog.yml
- type: Lifecycle
url: lifecycle/nekosia-lifecycle.yml
- type: Authentication
url: authentication/nekosia-authentication.yml
- type: Conventions
url: conventions/nekosia-conventions.yml
- type: Conformance
url: conformance/nekosia-conformance.yml
- type: ErrorCatalog
url: errors/nekosia-problem-types.yml
- type: DataModel
url: data-model/nekosia-data-model.yml
- type: Examples
url: examples/_index.yml
- type: Packages
url: packages/nekosia-packages.yml
- type: SDKs
url: packages/nekosia-packages.yml
- type: RateLimits
url: rate-limits/nekosia-rate-limits.yml
- type: Plans
url: plans/nekosia-plans-pricing.yml
- type: WellKnown
url: well-known/nekosia-well-known.yml
- type: SecurityTxt
url: well-known/nekosia-security.txt
- type: LLMsTxt
url: llms/nekosia-llms.txt
- type: GitHubRepository
url: https://github.com/Nekosia-API/documentation
- type: X-Documentation-Source
url: https://raw.githubusercontent.com/Nekosia-API/documentation/main/endpoints.md
x-enrichment:
date: '2026-08-19'
status: enriched
artifacts_added: 24
pass: local-v1
x-no-contract:
openapi: false
asyncapi: false
graphql: false
mcp: false
agent_card: false
detail: 'STEP 0b contract discovery ran in full against api.nekosia.cat, nekosia.cat and cdn.nekosia.cat and found no machine-readable
contract of any kind. Probed and recorded: /openapi.json, /openapi.yaml, /swagger.json, /api-docs, /docs, /redoc, /rapidoc,
/spec, /api/v1/openapi.json (404 on the API host; the edge returned 403 for /openapi.yaml on nekosia.cat), /graphql (404),
/mcp and /api/v1/mcp (404), /llms.txt (404), and /.well-known/agent-card.json plus the legacy /.well-known/agent.json
on all three hosts (404). The API is real, live and well documented — the description of it is human-readable prose only.
See conformance/nekosia-conformance.yml.'
checked: '2026-08-19'
x-evidence:
round: '2026-08-19'
admitted_from: Add-API gate auto-publish 2026-08-19 02:46 UTC, confidence 90.
renamed: nekosia-api -> nekosia, domain-derived slug (nekosia.cat). Renamed BEFORE enrichment so artifacts were written
with the correct names. Never published under the old slug.
the_split_surface:
finding: The API host is wide open. The website host blocks machines outright.
api.nekosia.cat: 'root 200, invented path 404 — discriminates. Keyless: a live unauthenticated GET /api/v1/images/catgirl
returned 200 with a full payload on 2026-08-19.'
nekosia.cat: 'CORRECTED 2026-08-19, same day. First recorded as "403 on EVERY path ... a WAF block, not a JS challenge".
That was wrong. The block is USER-AGENT BASED: a default curl/SDK/agent UA gets 403 with a 4,572b Cloudflare "Attention
Required" page, but the SAME URL with an ordinary Chrome UA returns 200 — the documentation page is 24,154b of real
HTML. Not a WAF challenge, not unreachable: a UA filter that any browser passes and most non-browser clients fail.'
consequence: The eight nekosia.cat/documentation?page=... pointers are kept and ARE reachable — but only to a client that
sends a browser user-agent. An agent, SDK or crawler using its own UA gets 403. That is an agent-readiness problem rather
than a dead-pointer problem, and it is cheap for the provider to fix.
verified_reachable: status.nekosia.cat 200, discord.gg invite 200, github.com/Nekosia-API 200.
documentation_is_readable_after_all: The docs are NOT machine-unreachable, they are just not readable at nekosia.cat. The
source of truth is a public GitHub repo — Nekosia-API/documentation, pushed 2026-08-03 — and raw.githubusercontent.com/Nekosia-API/documentation/main/endpoints.md
returns 200 text/plain 9,421b. Wired as X-Documentation-Source so the machine-readable path is recorded alongside the
blocked canonical one.
no_openapi: No OpenAPI, on either host or in the GitHub org. The pipeline deliberately did NOT derive one — there is no
openapi/ directory in this repo. The data-model artifact reconstructs the response shape from the provider's own published
schema and states in its own derivation_note that every field was observed on the wire. That is ours, labelled as ours,
and not recorded as a contract they publish.
also_ships: An official JavaScript SDK, Nekosia-API/nekosia.js, pushed 2026-08-06.
no_llms_txt: 'Established only after the UA correction: with a browser UA, /llms.txt returns an honest 404 (5,806b). The
earlier 403 masked the absence. Nekosia publishes no llms.txt.'
correction_note: Recorded rather than silently amended. The original claim went out in commit ecf25d2 and was wrong about
the mechanism; a browser-UA retry while profiling sniffcat, which showed the same behaviour, is what surfaced it.
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