# Services from dev-reference.x402tookit.com on Zero

> dev-reference.x402tookit.com serves 12 paid API services for AI agents, indexed by Zero. Each is callable per call with payment handled by Zero.

Canonical page: https://www.zero.xyz/host/dev-reference.x402tookit.com
Live health (JSON, refreshed every minute): https://www.zero.xyz/host/dev-reference.x402tookit.com/health.json

## Services

- [Dev Reference – CSP Header Explainer](https://www.zero.xyz/c/dev-reference-csp-header-explainer-81daf970/llms.txt): $0.02/call via x402. Parses a Content-Security-Policy header value, explains each directive in plain English, and flags risky settings like unsafe-inline with severity levels and fix suggestions.
- [Dev Reference – HTTP Status Code Lookup](https://www.zero.xyz/c/dev-reference-http-status-code-lookup-dbbc2c90/llms.txt): $0.02/call via x402. Returns the meaning, typical cause, client action, and cacheability of any HTTP status code from the IANA registry and RFC 9110.
- [Dev Reference Unicode Character Lookup](https://www.zero.xyz/c/dev-reference-unicode-character-lookup-d4c91c58/llms.txt): $0.02/call via x402. Looks up a Unicode code point and returns its name, block, category, plane, UTF-8/UTF-16/UTF-32 bytes, and HTML/JS/CSS escape sequences.
- [Dev Reference: Cache-Control Header Explainer](https://www.zero.xyz/c/dev-reference-cache-control-header-explainer-b8300bcc/llms.txt): $0.02/call via x402. Parses a Cache-Control header value, explains each directive in plain language, computes freshness durations, and flags conflicts or sensitive data leaks.
- [Dev Reference: TCP/UDP Port Lookup](https://www.zero.xyz/c/dev-reference-tcp-udp-port-lookup-da0a2c02/llms.txt): $0.02/call via x402. Returns the IANA service name, common use description, supported protocols, and port range class for any TCP/UDP port number (0–65535)
- [Dev Reference MIME Type Lookup](https://www.zero.xyz/c/dev-reference-mime-type-lookup-1421df48/llms.txt): $0.02/call via x402. Returns the MIME/media type for a file extension, or the extensions for a given media type, along with IANA registration status and verdict.
- [Dev Reference: ISO 8601 / RFC 3339 Date-Time Validator](https://www.zero.xyz/c/dev-reference-iso-8601-rfc-3339-date-time-validator-f8bf87d4/llms.txt): $0.02/call via x402. Validates a date, time, timestamp, duration, or interval string against ISO 8601 and RFC 3339 standards, returning conformance flags, parsed metadata, and error details.
- [Dev Reference: Timestamp Format Converter](https://www.zero.xyz/c/dev-reference-timestamp-format-converter-92de3981/llms.txt): $0.02/call via x402. Converts a timestamp (RFC 3339, ISO 8601, HTTP-date, or epoch seconds) into multiple standard formats including RFC 3339, HTTP-date, RFC 5322, ISO 8601 basic, and epoch seconds/milliseconds.
- [Dev Reference – HTTP Header Lookup](https://www.zero.xyz/c/dev-reference-http-header-lookup-3bf34029/llms.txt): $0.02/call via x402. Returns the purpose, direction (request/response), security notes, and IANA registration status for a named HTTP header field.
- [Dev Reference DNS Record Type Lookup](https://www.zero.xyz/c/dev-reference-dns-record-type-lookup-fcf98ce8/llms.txt): $0.02/call via x402. Looks up a DNS record type by name (e.g. MX) or number (e.g. 15) and returns its IANA meaning, RFC reference, and typical use.
- [Dev Reference – HTTP Status Codes by Class](https://www.zero.xyz/c/dev-reference-http-status-codes-by-class-065b552c/llms.txt): $0.02/call via x402. Returns all registered HTTP status codes in a given class (1xx–5xx) with their names and one-line meanings.
- [Dev Reference: HTTP Method Lookup](https://www.zero.xyz/c/dev-reference-http-method-lookup-0daa6a8c/llms.txt): $0.02/call via x402. Returns whether an HTTP method is safe and idempotent per IANA registry, its purpose, and request-body semantics.

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

- [Zero catalog index](https://www.zero.xyz/llms.txt)