HTTP status codes, MIME types & IANA TLDs in one edge API
Developer Reference API
The Developer Reference API is the single source of truth for the boring-but-essential lookups your code needs: what HTTP 425 means, the MIME type for a .heic file, and whether .zip is a real top-level domain.
It bundles a hand-curated table of standard HTTP status codes, the full IANA mime-db (2,600+ media types), and the complete IANA root-zone TLD list (1,400+ domains) into one clean JSON API served from the edge with zero upstream calls.
Free tier included, no credit card required. One key works across all 49 APIs.
- MIME Types
- 2,600+
- IANA TLDs
- 1,400+
- Lookup Speed
- O(1)
Key features
- Describe any standard HTTP status code (100-599)
- List and filter status codes by category
- Look up MIME type charset, compressibility, source and extensions
- Resolve MIME type(s) from a file extension
- Validate TLDs against the IANA root zone
- List and prefix-search IANA top-level domains
- Case-insensitive matching with leading-dot tolerance
- Zero upstream calls — pure in-memory edge lookups
Built for
- API gateways validating Content-Type headers
- Devtools and dashboards rendering status-code docs
- Domain-availability and registrar UIs
- Email and file-upload validators
- Translating codes or extensions into human-readable text
- Content negotiation and compression decisions
- Form validation for domain inputs
- Backend services normalizing media types
Try it
Build the request for your data
Edit the parameters below and see the exact curl command and JSON response you will get. No key required to preview.
Parameters
GET /reference/v1/http-status/404?apikey=YOUR_KEY HTTP/1.1
Host: api.apicodex.io
{
"code": 404,
"message": "Not Found",
"category": "Client Error",
"description": "The server cannot find the requested resource. The endpoint may be valid but the resource itself does not exist."
}Documentation
Developer Reference API Documentation
The Developer Reference API exposes fast, fully-offline lookups for HTTP status codes, IANA MIME types, and IANA top-level domains. All data is bundled at the edge, so responses are O(1) Map/Set lookups returned as clean JSON.
Base URL
https://api.apicodex.ioAuthentication
Authenticate every request by appending your API key as the apikey query parameter:
GET /reference/v1/http-status/404?apikey=YOUR_KEYRequest and response
Illustrative values. Confirm current endpoint behavior, quotas, and data freshness in the API documentation before production use.
GET /reference/v1/http-status/404?apikey=YOUR_KEY{
"code": 404,
"message": "Not Found",
"category": "Client Error",
"description": "The server cannot find the requested resource. The endpoint may be valid but the resource itself does not exist."
}Code examples
curl --request GET \
--url 'https://api.apicodex.io/reference/v1/mime/extension/json?apikey=YOUR_KEY'Endpoints
GET /reference/v1/http-status/{code}
Describe one HTTP status code — returns message, category and description.
/reference/v1/http-status/404?apikey=YOUR_KEYGET /reference/v1/http-status
List all known HTTP status codes, optionally filtered by category and limited.
/reference/v1/http-status?category=Server%20Error&limit=2&apikey=YOUR_KEYGET /reference/v1/mime/type/{type}
Look up charset, compressibility, source and extensions for a URL-encoded MIME type.
/reference/v1/mime/type/application%2Fjson?apikey=YOUR_KEYGET /reference/v1/mime/extension/{ext}
Return every MIME type associated with a file extension.
/reference/v1/mime/extension/json?apikey=YOUR_KEYGET /reference/v1/tld/{tld}
Check whether a top-level domain exists in the IANA root zone list.
/reference/v1/tld/.COM?apikey=YOUR_KEYGET /reference/v1/tlds
List IANA top-level domains, optionally filtered by prefix and limited.
/reference/v1/tlds?startsWith=co&limit=3&apikey=YOUR_KEYQuery Parameters
Required parameters
apikeyYour API key, passed as a query parameter on every request.
Optional parameters
categoryHTTP status list filter: Informational, Success, Redirection, Client Error or Server Error (case-insensitive; accepts kebab/space variants).limitMaximum items to return (1-1000). Status list defaults to all; TLD list defaults to 200.startsWithLowercased prefix filter for the TLD list (letters, digits, hyphens).
Pricing
Developer Reference API Pricing
One key, one subscription, all 49 APIs. Start free and upgrade when you grow. No minimums, no lock-in.
This API costs 1 credit per request. Credits are shared across every API on your plan.
Estimate your monthly cost
Drag the slider to match your expected request volume. We will recommend the cheapest plan that covers it.
Recommended plan
Starter
$29.99 /month
Free
- All 49 APIs included
- No credit card required
- Full documentation and examples
Starter
Popular- All 49 APIs included
- Email support
- Usage dashboard and analytics
Pro
- All 49 APIs included
- Priority support
- Up to 5 API keys
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Coming soon · MCP
Use the Developer Reference API from your AI agent
The API Codex MCP server will expose this API, and the other 39, to Claude, Cursor and any MCP client as tools. Same key, same credits, one config entry.
FAQ
Frequently asked questions
Three datasets: a hand-curated table of standard HTTP status codes (100-599) with messages, categories and descriptions; the full IANA mime-db of 2,600+ media types with charset, compressibility, source and file extensions; and the complete IANA root-zone TLD list of 1,400+ top-level domains. All three are bundled at the edge and queried through one API.
Authentication is a single query parameter. Append ?apikey=YOUR_KEY to any endpoint, for example GET /reference/v1/http-status/404?apikey=YOUR_KEY. You can also send the key as an X-Api-Key header. Create a free key at dash.apicodex.io.
Every dataset is shipped to the edge and indexed in memory, so each lookup is an O(1) Map or Set hit with zero upstream calls. There are no third-party services to wait on and no cold dependencies, which means responses typically return in single-digit milliseconds from the network edge nearest your users.
Matching is case-insensitive across the board. MIME type lookups accept the URL-encoded type in any casing. File extension and TLD lookups tolerate a leading dot and any casing, so .COM, com, and COM all resolve identically. The status list category filter also accepts kebab and space variants such as client-error.
Yes. /reference/v1/http-status lists every status code and accepts a category filter (Informational, Success, Redirection, Client Error, Server Error) plus a limit of 1-1000. /reference/v1/tlds lists top-level domains and accepts a lowercased startsWith prefix and a limit (default 200). The single-value endpoints return one entry; the list endpoints return a count, total, and an items/tlds array.
The API returns clear, documented error responses. Malformed input — like a non-3-digit status code, an invalid category, or an empty extension — returns a 400 with an error message and, where relevant, the list of allowed values. Unknown-but-well-formed values, such as an unknown MIME type or a status code outside the standard set, return a 404 echoing the value you queried.
No. The Developer Reference API is fully offline by design. All data is bundled into the edge Worker, so there are no upstream lookups, no third-party rate limits, and no flaky dependencies. This makes it safe to put on a hot path like an API gateway validating Content-Type headers on every request.
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