REST · CORS enabled · No keys · 120 req/min

Fetch reference data for your project

Read the example response, then send a GET request for the rows you need. Every dataset is available as JSON, YAML or TOON without an account or API key.

Dynamic endpoints

Query the live database. Every endpoint accepts ?format= (json, yaml, toon); the default is JSON.

List all categories

GET /api/ GET /api/?format=yaml

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One category with its datasets

GET /api/category/{slug} GET /api/category/programming-languages?format=yaml

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A single dataset

GET /api/dataset/{slug} GET /api/dataset/http-status-codes-complete?format=toon

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Search (titles, descriptions, tags and data; 2+ characters)

GET /api/search?q={query} GET /api/search?q=python&format=json

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One dataset, three encodings

GET /api/dataset/tcp-ip-protocol-suite in each format. The three carry identical data; this is the real output, read from the files the API serves.

JSON · 2,091 bytes · ?format=json

{
    "api": "YAML JSON TOON Database",
    "version": "1.0.0",
    "format": "json",
    "dataset": {
        "slug": "tcp-ip-protocol-suite",
        "title": "TCP/IP Protocol Suite",
        "description": "Layers and core protocols of the TCP/IP model.",
        "summary": "The four-layer TCP/IP model with the protocols that live at each layer: application, transport, internet and network access. It is the model the internet actually uses and a compact reference for where a given protocol belongs.",
        "use_when": [
            "You want the simpler four-layer view instead of the seven-layer OSI model.",
            "You are placing a protocol such as DNS, TCP or ARP in its layer."
        ],
        "caveats": [
            "The layer names are not used identically in every textbook; some split network access into link and physical.",
            "Protocols such as ARP and TLS do not fit one layer cleanly."
        ],
        "related": [
            "osi-model-layers",
            "network-ports-reference",
            "dns-fundamentals"
        ],
        "category": "Networking",
        "category_slug": "networking",
        "tags": "networking,tcp,ip,protocols",
        "view_count": 0,
        "entry_count": 4,
        "fields": [
            {
                "section": "data",
                "field": "layer",
                "type": "string",
                "example": "Application"
            },
            {
                "section": "data",
                "field": "protocols",
                "type": "string",
                "example": "HTTP, HTTPS, FTP, SMTP, DNS, SSH"
            }
        ]
    },
    "data": [
        {
            "layer": "Application",
            "protocols": "HTTP, HTTPS, FTP, SMTP, DNS, SSH"
        },
        {
            "layer": "Transport",
            "protocols": "TCP, UDP"
        },
        {
            "layer": "Internet",
            "protocols": "IP, ICMP, ARP, IGMP"
        },
        {
            "layer": "Network Access",
            "protocols": "Ethernet, Wi-Fi, PPP"
        }
    ]
}

YAML · 1,437 bytes · ?format=yaml

api: YAML JSON TOON Database
version: 1.0.0
format: json
dataset:
  slug: tcp-ip-protocol-suite
  title: TCP/IP Protocol Suite
  description: Layers and core protocols of the TCP/IP model.
  summary: "The four-layer TCP/IP model with the protocols that live at each layer: application, transport, internet and network access. It is the model the internet actually uses and a compact reference for where a given protocol belongs."
  use_when:
    - You want the simpler four-layer view instead of the seven-layer OSI model.
    - You are placing a protocol such as DNS, TCP or ARP in its layer.
  caveats:
    - The layer names are not used identically in every textbook; some split network access into link and physical.
    - Protocols such as ARP and TLS do not fit one layer cleanly.
  related:
    - osi-model-layers
    - network-ports-reference
    - dns-fundamentals
  category: Networking
  category_slug: networking
  tags: networking,tcp,ip,protocols
  view_count: 0
  entry_count: 4
  fields:
    - section: data
      field: layer
      type: string
      example: Application
    - section: data
      field: protocols
      type: string
      example: HTTP, HTTPS, FTP, SMTP, DNS, SSH
data:
  - layer: Application
    protocols: HTTP, HTTPS, FTP, SMTP, DNS, SSH
  - layer: Transport
    protocols: TCP, UDP
  - layer: Internet
    protocols: IP, ICMP, ARP, IGMP
  - layer: Network Access
    protocols: Ethernet, Wi-Fi, PPP

TOON · 1,271 bytes · ?format=toon

api: YAML JSON TOON Database
version: 1.0.0
format: json
dataset:
  slug: tcp-ip-protocol-suite
  title: TCP/IP Protocol Suite
  description: Layers and core protocols of the TCP/IP model.
  summary: "The four-layer TCP/IP model with the protocols that live at each layer: application, transport, internet and network access. It is the model the internet actually uses and a compact reference for where a given protocol belongs."
  use_when[2]: You want the simpler four-layer view instead of the seven-layer OSI model.,"You are placing a protocol such as DNS, TCP or ARP in its layer."
  caveats[2]: The layer names are not used identically in every textbook; some split network access into link and physical.,Protocols such as ARP and TLS do not fit one layer cleanly.
  related[3]: osi-model-layers,network-ports-reference,dns-fundamentals
  category: Networking
  category_slug: networking
  tags: "networking,tcp,ip,protocols"
  view_count: 0
  entry_count: 4
  fields[2]{section,field,type,example}:
    data,layer,string,Application
    data,protocols,string,"HTTP, HTTPS, FTP, SMTP, DNS, SSH"
data[4]{layer,protocols}:
  Application,"HTTP, HTTPS, FTP, SMTP, DNS, SSH"
  Transport,"TCP, UDP"
  Internet,"IP, ICMP, ARP, IGMP"
  Network Access,"Ethernet, Wi-Fi, PPP"

Static file endpoints

Pre-generated files for direct access without a database query — ideal for static hosting or CDN caching. They are identical to the API's responses and are not rate limited by the API.

GET /static-data/categories.json
GET /static-data/catalog-index.json
GET /static-data/catalog-index.toon
GET /static-data/search-index.json
GET /static-data/stats.json
GET /static-data/category/{slug}.json
GET /static-data/dataset/{slug}.json
GET /static-data/dataset/{slug}.yaml
GET /static-data/dataset/{slug}.toon

Human-readable catalog

The same data rendered as HTML tables, for people and for crawlers. One page per dataset, one per category, plus an index. Every page links to its own JSON, YAML, and TOON files and carries Dataset structured data.

GET /catalog/
GET /catalog/{category}/
GET /catalog/{category}/{dataset}/

Want to see the encoding difference on your own payload? Paste JSON into TOON Studio — it runs the same encoder as /api/ in the browser and reports exact byte counts.

Response headers

Every API response carries rate-limit headers and open CORS, so browsers can call it directly.

X-RateLimit-Limit: 120
X-RateLimit-Window: 60
Access-Control-Allow-Origin: *

About TOON

TOON (Token-Oriented Object Notation) is a compact text format for putting structured data into LLM prompts. A uniform array of objects becomes a table: the field names are written once in a header (data[4]{layer,protocols}:) and each row carries only values. Across all 205 datasets TOON uses 33% fewer tokens than the JSON files served here (o200k_base tokenizer) — and far more on table-shaped data, though prose-heavy datasets gain little. The encoder follows the public format and is checked against its reference implementation on every build.

JSON has widely available parsers. YAML uses indentation for readable keys and values. All three formats contain identical data. See the measurement →

Rate limits

API requests are limited to 120 per minute per IP. The limiter stores hashes of the IP and browser headers to track requests and cooldowns; this is separate from hosting access logs. Exceeding the limit returns HTTP 429 with a Retry-After header. How to back off →

The books

Open Data for AGI — $4.99

The strategy companion to this API: why public, free, and open datasets decide what AGI becomes. View the ebook on Gumroad → · Read more

Building agents for a living? How to Remain Valuable When Intelligence Becomes Cheap is the 224-page companion on the human advantages that survive cheap cognition — judgment, ownership, and taste. PDF + EPUB.