# Dev Reference

Developer reference lookups for agents: HTTP status codes, headers, CSP and Cache-Control explainers, MIME types, ports, DNS record types, ISO 8601 and Unicode.

## How to pay

Machine-payable over x402. USDC on: Base (eip155:8453), Solana (solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp), Polygon (eip155:137), Arbitrum One (eip155:42161).
No accounts. No API keys. No signup. The paying wallet is the account.

## Machine-readable

- OpenAPI: https://dev-reference.x402tookit.com/openapi.json
- x402 manifest: https://dev-reference.x402tookit.com/.well-known/x402
- Catalog (free): https://dev-reference.x402tookit.com/catalog
- Health (free): https://dev-reference.x402tookit.com/health
- Uptime (free): https://dev-reference.x402tookit.com/uptime

## Endpoints (12)

### GET /cache-control-explain — $0.02
Parse a Cache-Control value, explain each directive, compute freshness and flag conflicts or leaks.
Params: value: string, kind?: string, usage?: string
Example: https://dev-reference.x402tookit.com/cache-control-explain?value=public%2C+max-age%3D3600%2C+no-cache&kind=response

### GET /csp-explain — $0.02
Parse a Content-Security-Policy header value, explain each directive and flag risky settings like unsafe-inline.
Params: value: string
Example: https://dev-reference.x402tookit.com/csp-explain?value=default-src+%27self%27%3B+script-src+%27self%27+%27unsafe-inline%27+https%3A%2F%2Fcdn.jsdelivr.net%3B+img-src+*

### GET /datetime-convert — $0.02
Convert a timestamp (RFC 3339, ISO 8601, HTTP-date or epoch seconds) to RFC 3339, HTTP-date, RFC 5322, basic ISO and epoch.
Params: value?: string, epoch?: number, assumeOffset?: string
Example: https://dev-reference.x402tookit.com/datetime-convert?value=1994-11-06T08%3A49%3A37Z

### GET /datetime-validate — $0.02
Validate an ISO 8601 or RFC 3339 date, time, timestamp, duration or interval, and say which standard it satisfies.
Params: value: string
Example: https://dev-reference.x402tookit.com/datetime-validate?value=1996-12-19T16%3A39%3A57-08%3A00

### GET /dns-record-type — $0.02
DNS record type lookup by name (MX) or number (15): IANA meaning, RFC reference and typical use.
Params: type: string
Example: https://dev-reference.x402tookit.com/dns-record-type?type=HTTPS

### GET /http-header — $0.02
Explain an HTTP header: request or response, purpose, security notes, and its IANA registration status.
Params: name: string
Example: https://dev-reference.x402tookit.com/http-header?name=Strict-Transport-Security

### GET /http-method — $0.02
Whether an HTTP method is safe and idempotent (IANA registry), what it is for, and request-body semantics.
Params: method: string
Example: https://dev-reference.x402tookit.com/http-method?method=PUT

### GET /http-status-class — $0.02
All registered HTTP status codes in a class (1xx to 5xx) with names and one-line meanings.
Params: class: integer
Example: https://dev-reference.x402tookit.com/http-status-class?class=3

### GET /http-status — $0.02
HTTP status code meaning, typical cause, client action and cacheability, from the IANA registry and RFC 9110.
Params: code: integer
Example: https://dev-reference.x402tookit.com/http-status?code=429

### GET /mime-type — $0.02
Media type (MIME) for a file extension, or extensions for a media type, with IANA registration status.
Params: ext?: string, type?: string
Example: https://dev-reference.x402tookit.com/mime-type?ext=webp

### GET /port-lookup — $0.02
IANA service name and common use for a TCP/UDP port (about 130 well-known ports), plus the port range class.
Params: port: integer
Example: https://dev-reference.x402tookit.com/port-lookup?port=443

### GET /unicode-char — $0.02
Unicode character lookup by code point or character: name, block, category, UTF-8/UTF-16 bytes and HTML/JS/CSS escapes.
Params: cp: string
Example: https://dev-reference.x402tookit.com/unicode-char?cp=U%2B1F600

## Terms

Reference data is embedded from the IANA registries (retrieved 2026-10-11) and Unicode data files plus curated explanations, provided as is, with no warranty. Header explainers flag common risks only and are not a security audit. Verify against the current standards before relying on a value.