Tools API

Tools API Reference

Every utility under /tools documented per-endpoint: parameters, curl examples and response shapes. Machine-readable version: OpenAPI 3.1 · Interactive overview: /docs/api.

Conventions

Endpoint

POST /api/v1/tools/:slug with a JSON body. No authentication required (public utilities).

Limits

Rate limit: 60 requests/min per IP → 429 + Retry-After
Input ceiling: 64 KB → 413 PAYLOAD_TOO_LARGE
Errors: RFC 9457 application/problem+json bodies
Unknown slug → 404 NOT_FOUND (no echo mock)

# Try it now

curl -X POST https://yas.sh/api/v1/tools/hash-calculator \

-H "Content-Type: application/json" \

-d '{"input":"hello","algo":"sha256"}'

ALL TOOLS AT A GLANCE

Tool	Category	Server API	Reference
Base64 Textbase64-text	Encoding	POST /api/v1/tools/base64-text	contract ↓
Base64 Filebase64-file	Encoding	browser-only	why ↓
JSON Validatorjson-validator	Validation	POST /api/v1/tools/json-validator	contract ↓
XML Validatorxml-validator	Validation	browser-only	why ↓
Text Comparisontext-diff	Text	POST /api/v1/tools/text-diff	contract ↓
JSON / XML Converterjson-xml	Conversion	browser-only	why ↓
CSV Convertercsv-converter	Conversion	browser-only	why ↓
JSON Formatterjson-formatter	Formatting	POST /api/v1/tools/json-formatter	contract ↓
URL Encoderurl-encoder	Formatting	POST /api/v1/tools/url-encoder	contract ↓
Password Generatorpassword-generator	Generators	POST /api/v1/tools/password-generator	contract ↓
Hash Calculatorhash-calculator	Generators	POST /api/v1/tools/hash-calculator	contract ↓
UUID Generatoruuid-generator	Generators	POST /api/v1/tools/uuid-generator	contract ↓
Random Stringrandom-string	Generators	POST /api/v1/tools/random-string	contract ↓
Unix Timestampunix-timestamp	Generators	POST /api/v1/tools/unix-timestamp	contract ↓
JWT Decoderjwt-decoder	Web	POST /api/v1/tools/jwt-decoder	contract ↓
Regex Testerregex-tester	Web	POST /api/v1/tools/regex-tester	contract ↓
HTML Escapehtml-escape	IT Ops	POST /api/v1/tools/html-escape	contract ↓
String Lengthstring-length	IT Ops	POST /api/v1/tools/string-length	contract ↓
Case Convertercase-converter	IT Ops	POST /api/v1/tools/case-converter	contract ↓
SQL Formattersql-formatter	IT Ops	browser-only	why ↓
Credit Card Validatorcredit-card-validator	IT Ops	POST /api/v1/tools/credit-card-validator	contract ↓
IP Validatorip-validator	IT Ops	POST /api/v1/tools/ip-validator	contract ↓
MAC Validatormac-validator	IT Ops	POST /api/v1/tools/mac-validator	contract ↓
Lorem Ipsumlorem-generator	IT Ops	POST /api/v1/tools/lorem-generator	contract ↓
Checksum Calculatorchecksum	IT Ops	POST /api/v1/tools/checksum	contract ↓
QR Generatorqr-generator	IT Ops	POST /api/v1/tools/qr-generator	contract ↓
UTM Builderutm-builder	Marketing	POST /api/v1/tools/utm-builder	contract ↓
Link Checkerlink-checker	Marketing	browser-only	why ↓
What Is My IPwhat-is-my-ip	Network	POST /api/v1/tools/what-is-my-ip	contract ↓
My IP (plain)ip	Network	POST /api/v1/tools/ip	contract ↓
DNS Lookupdns-lookup	Network	POST /api/v1/tools/dns-lookup	contract ↓
IP Subnet Calculatorip-subnet-calculator	Network	POST /api/v1/tools/ip-subnet-calculator	contract ↓
TLS Analyzertls-analyzer	Network	POST /api/v1/tools/tls-analyzer	contract ↓
DANE / TLSAdane-tlsa	Network	POST /api/v1/tools/dane-tlsa	contract ↓
SPF Inspectorspf-inspector	Email Security	POST /api/v1/tools/spf-inspector	contract ↓
DMARC Inspectordmarc-inspector	Email Security	POST /api/v1/tools/dmarc-inspector	contract ↓
DKIM Inspectordkim-inspector	Email Security	POST /api/v1/tools/dkim-inspector	contract ↓
MX Healthmx-health	Email Security	POST /api/v1/tools/mx-health	contract ↓
MTA-STS & TLS-RPTmta-sts-tlsrpt	Email Security	POST /api/v1/tools/mta-sts-tlsrpt	contract ↓
URL Parserurl-parser	Web	POST /api/v1/tools/url-parser	contract ↓
HTTP Status Codeshttp-status-codes	Web	POST /api/v1/tools/http-status-codes	contract ↓
Cron Parsercron-parser	Web	POST /api/v1/tools/cron-parser	contract ↓
Color Convertercolor-converter	Conversion	POST /api/v1/tools/color-converter	contract ↓
Number Base Converternumber-base-converter	Conversion	POST /api/v1/tools/number-base-converter	contract ↓
Markdown → HTMLmarkdown-to-html	Conversion	POST /api/v1/tools/markdown-to-html	contract ↓
CSV → JSONcsv-to-json	Conversion	POST /api/v1/tools/csv-to-json	contract ↓
Slug Generatorslug-generator	Text	POST /api/v1/tools/slug-generator	contract ↓
Text Sortertext-sorter	Text	POST /api/v1/tools/text-sorter	contract ↓
Readability Scorereadability-score	Text	POST /api/v1/tools/readability-score	contract ↓
chmod Calculatorchmod-calculator	IT Ops	POST /api/v1/tools/chmod-calculator	contract ↓
Date Differencedate-difference	IT Ops	POST /api/v1/tools/date-difference	contract ↓
Password Strengthpassword-strength	Security	POST /api/v1/tools/password-strength	contract ↓

SERVER TOOL CONTRACTS

Base64 Text

base64-textPOST /api/v1/tools/base64-text

Encode or decode a UTF-8 string with Base64.

Parameter	Type	Default	Description
input*	string	—	Text to transform (≤ 64 KB)
mode	"encode" \| "decode"	"encode"	Direction

REQUEST

curl -X POST https://yas.sh/api/v1/tools/base64-text \
  -H "Content-Type: application/json" \
  -d '{"input":"hello world","mode":"encode"}'

RESPONSE (200)

{ "slug": "base64-text", "result": "aGVsbG8gd29ybGQ=", "mode": "encode" }

Hash Calculator

hash-calculatorPOST /api/v1/tools/hash-calculator

Cryptographic digest of a string.

Parameter	Type	Default	Description
input*	string	—	Text to hash (≤ 64 KB)
algo	string	"sha256"	One of md5, sha1, sha256, sha384, sha512

REQUEST

curl -X POST https://yas.sh/api/v1/tools/hash-calculator \
  -H "Content-Type: application/json" \
  -d '{"input":"hello","algo":"md5"}'

RESPONSE (200)

{ "slug": "hash-calculator", "algo": "md5", "result": "5d41402abc4b2a76b9719d911017c592" }

Checksum Calculator

checksumPOST /api/v1/tools/checksum

Identical to hash-calculator (checksum semantics).

Parameter	Type	Default	Description
input*	string	—	Text to checksum (≤ 64 KB)
algo	string	"sha256"	md5 \| sha1 \| sha256 \| sha384 \| sha512

REQUEST

curl -X POST https://yas.sh/api/v1/tools/checksum \
  -H "Content-Type: application/json" \
  -d '{"input":"hello","algo":"sha1"}'

RESPONSE (200)

{ "slug": "checksum", "algo": "sha1", "result": "aaf4c61ddcc5e8a2dabede0f3b482cd9aea9434d" }

UUID Generator

uuid-generatorPOST /api/v1/tools/uuid-generator

Generate 1–50 random UUIDs (v4).

Parameter	Type	Default	Description
count	integer	1	How many (1–50)

REQUEST

curl -X POST https://yas.sh/api/v1/tools/uuid-generator \
  -H "Content-Type: application/json" \
  -d '{"count":2}'

RESPONSE (200)

{ "slug": "uuid-generator", "count": 2, "result": ["<uuid>", "<uuid>"] }

URL Encoder

url-encoderPOST /api/v1/tools/url-encoder

Percent-encode / percent-decode a string.

Parameter	Type	Default	Description
input*	string	—	Text or URL fragment
mode	"encode" \| "decode"	"encode"	Direction

REQUEST

curl -X POST https://yas.sh/api/v1/tools/url-encoder \
  -H "Content-Type: application/json" \
  -d '{"input":"a b&c=d","mode":"encode"}'

RESPONSE (200)

{ "slug": "url-encoder", "result": "a%20b%26c%3Dd", "mode": "encode" }

Case Converter

case-converterPOST /api/v1/tools/case-converter

Convert text between naming conventions.

Parameter	Type	Default	Description
input*	string	—	Source text
mode	string	"upper"	upper \| lower \| title \| camel \| pascal \| snake \| kebab

REQUEST

curl -X POST https://yas.sh/api/v1/tools/case-converter \
  -H "Content-Type: application/json" \
  -d '{"input":"hello world","mode":"kebab"}'

RESPONSE (200)

{ "slug": "case-converter", "result": "hello-world", "mode": "kebab" }

HTML Escape

html-escapePOST /api/v1/tools/html-escape

Escape or unescape HTML entities (& < > " ').

Parameter	Type	Default	Description
input*	string	—	HTML or plain text
mode	"encode" \| "decode"	"encode"	Direction

REQUEST

curl -X POST https://yas.sh/api/v1/tools/html-escape \
  -H "Content-Type: application/json" \
  -d '{"input":"<b>hi</b>","mode":"encode"}'

RESPONSE (200)

{ "slug": "html-escape", "result": "&lt;b&gt;hi&lt;/b&gt;", "mode": "encode" }

String Length

string-lengthPOST /api/v1/tools/string-length

Count characters (code points), bytes, words and lines.

Parameter	Type	Default	Description
input*	string	—	Any text

REQUEST

curl -X POST https://yas.sh/api/v1/tools/string-length \
  -H "Content-Type: application/json" \
  -d '{"input":"héllo\nworld"}'

RESPONSE (200)

{ "slug": "string-length", "result": { "chars": 11, "bytes": 12, "words": 2, "lines": 2 } }

JSON Validator

json-validatorPOST /api/v1/tools/json-validator

Validate JSON syntax; returns the parser error if invalid.

Parameter	Type	Default	Description
input*	string	—	JSON text

REQUEST

curl -X POST https://yas.sh/api/v1/tools/json-validator \
  -H "Content-Type: application/json" \
  -d '{"input":"{\"a\":}"}'

RESPONSE (200)

{ "slug": "json-validator", "valid": false, "error": "..." }

JSON Formatter

json-formatterPOST /api/v1/tools/json-formatter

Beautify (2-space indent) or minify JSON.

Parameter	Type	Default	Description
input*	string	—	JSON text
mode	"beautify" \| "minify"	"beautify"	Direction

REQUEST

curl -X POST https://yas.sh/api/v1/tools/json-formatter \
  -H "Content-Type: application/json" \
  -d '{"input":"{\"a\":1,\"b\":[2,3]}","mode":"minify"}'

RESPONSE (200)

{ "slug": "json-formatter", "result": "{\"a\":1,\"b\":[2,3]}", "mode": "minify" }

Password Generator

password-generatorPOST /api/v1/tools/password-generator

CSPRNG passwords, 8–128 chars, optional alnum-only sets.

Parameter	Type	Default	Description
length	integer	20	8–128
count	integer	1	1–10 passwords
mode	"full" \| "alnum"	"full"	Charset (full includes symbols, unambiguous alnum)

REQUEST

curl -X POST https://yas.sh/api/v1/tools/password-generator \
  -H "Content-Type: application/json" \
  -d '{"length":24,"count":1}'

RESPONSE (200)

{ "slug": "password-generator", "length": 24, "result": "<password>" }

Random String

random-stringPOST /api/v1/tools/random-string

Random string from a named charset.

Parameter	Type	Default	Description
length	integer	16	1–256
mode	string	"alnum"	alnum \| alpha \| numeric \| hex

REQUEST

curl -X POST https://yas.sh/api/v1/tools/random-string \
  -H "Content-Type: application/json" \
  -d '{"length":32,"mode":"hex"}'

RESPONSE (200)

{ "slug": "random-string", "length": 32, "charset": "hex", "result": "<hex>" }

Unix Timestamp

unix-timestampPOST /api/v1/tools/unix-timestamp

Convert a unix timestamp (s/ms) ↔ ISO/UTC date.

Parameter	Type	Default	Description
input*	string	—	e.g. 1754500000, 1754500000000, or an ISO date (blank = now)

REQUEST

curl -X POST https://yas.sh/api/v1/tools/unix-timestamp \
  -H "Content-Type: application/json" \
  -d '{"input":"1754500000"}'

RESPONSE (200)

{ "slug": "unix-timestamp", "result": { "unix": 1754500000, "iso": "2025-08-06T18:26:40.000Z", "utc": "..." } }

JWT Decoder

jwt-decoderPOST /api/v1/tools/jwt-decoder

Decode a JWT header & payload (NO signature verification — explicitly flagged).

Parameter	Type	Default	Description
input*	string	—	The 3-segment token

REQUEST

curl -X POST https://yas.sh/api/v1/tools/jwt-decoder \
  -H "Content-Type: application/json" \
  -d '{"input":"eyJhbGciOiJIUzI1NiJ9.eyJzdWIiOiIxMjMifQ.sig"}'

RESPONSE (200)

{ "slug": "jwt-decoder", "result": { "header": {...}, "payload": {...} }, "warning": "Decoded WITHOUT signature verification" }

Regex Tester

regex-testerPOST /api/v1/tools/regex-tester

Test a regex against a string (ReDoS-guarded, max 100 matches).

Parameter	Type	Default	Description
pattern*	string	—	≤ 500 chars; nested-quantifier patterns rejected
text*	string	—	Test string (≤ 10 KB)
flags	string	"g"	Subset of d g i m s u v y

REQUEST

curl -X POST https://yas.sh/api/v1/tools/regex-tester \
  -H "Content-Type: application/json" \
  -d '{"pattern":"(\\w+)@(\\w+)","text":"hello there world","flags":"g"}'

RESPONSE (200)

{ "slug": "regex-tester", "count": 2, "truncated": false, "result": [{ "match": "o t", "index": 4 }, ...] }

IP Validator

ip-validatorPOST /api/v1/tools/ip-validator

Validate IPv4 / IPv6 addresses.

Parameter	Type	Default	Description
input*	string	—	e.g. 192.168.1.1 or ::1

REQUEST

curl -X POST https://yas.sh/api/v1/tools/ip-validator \
  -H "Content-Type: application/json" \
  -d '{"input":"192.168.1.1"}'

RESPONSE (200)

{ "slug": "ip-validator", "result": { "input": "192.168.1.1", "valid": true, "version": 4 } }

MAC Validator

mac-validatorPOST /api/v1/tools/mac-validator

Validate MAC addresses (colon/hyphen/plain forms).

Parameter	Type	Default	Description
input*	string	—	e.g. 00:1B:44:11:3A:B7

REQUEST

curl -X POST https://yas.sh/api/v1/tools/mac-validator \
  -H "Content-Type: application/json" \
  -d '{"input":"00:1B:44:11:3A:B7"}'

RESPONSE (200)

{ "slug": "mac-validator", "result": { "input": "00:1B:44:11:3A:B7", "valid": true } }

Credit Card Validator

credit-card-validatorPOST /api/v1/tools/credit-card-validator

Luhn checksum + scheme detection (NOT an existence check).

Parameter	Type	Default	Description
input*	string	—	Digits; spaces/dashes tolerated

REQUEST

curl -X POST https://yas.sh/api/v1/tools/credit-card-validator \
  -H "Content-Type: application/json" \
  -d '{"input":"4242 4242 4242 4242"}'

RESPONSE (200)

{ "slug": "credit-card-validator", "result": { "valid": true, "scheme": "visa", "note": "Luhn checksum only" } }

Lorem Ipsum

lorem-generatorPOST /api/v1/tools/lorem-generator

1–10 paragraphs of lorem ipsum.

Parameter	Type	Default	Description
count	integer	3	Paragraphs (1–10)

REQUEST

curl -X POST https://yas.sh/api/v1/tools/lorem-generator \
  -H "Content-Type: application/json" \
  -d '{"count":1}'

RESPONSE (200)

{ "slug": "lorem-generator", "paragraphs": 1, "result": "Lorem ipsum ..." }

QR Generator

qr-generatorPOST /api/v1/tools/qr-generator

Render a QR code for an http/https URL as a PNG data-URL.

Parameter	Type	Default	Description
input*	string	—	http/https URL (≤ 2048 chars)
size	integer	512	128–1024 px

REQUEST

curl -X POST https://yas.sh/api/v1/tools/qr-generator \
  -H "Content-Type: application/json" \
  -d '{"input":"https://yas.sh","size":256}'

RESPONSE (200)

{ "slug": "qr-generator", "result": "data:image/png;base64,..." }

UTM Builder

utm-builderPOST /api/v1/tools/utm-builder

Append UTM parameters to a base URL.

Parameter	Type	Default	Description
input*	string	—	Base http/https URL
params.utm_source	string	—	≤ 200 chars
params.utm_medium	string	—	≤ 200 chars
params.utm_campaign	string	—	≤ 200 chars
params.utm_term	string	—	≤ 200 chars
params.utm_content	string	—	≤ 200 chars

REQUEST

curl -X POST https://yas.sh/api/v1/tools/utm-builder \
  -H "Content-Type: application/json" \
  -d '{"input":"https://yas.sh/pricing","params":{"utm_source":"newsletter","utm_medium":"email","utm_campaign":"launch"}}'

RESPONSE (200)

{ "slug": "utm-builder", "result": "https://yas.sh/pricing?utm_source=newsletter&utm_medium=email&utm_campaign=launch" }

Text Comparison

text-diffPOST /api/v1/tools/text-diff

Line-based diff (LCS) between two texts (≤ 2,000 lines each).

Parameter	Type	Default	Description
a*	string	—	Left text (≤ 50 KB)
b*	string	—	Right text (≤ 50 KB)

REQUEST

curl -X POST https://yas.sh/api/v1/tools/text-diff \
  -H "Content-Type: application/json" \
  -d '{"a":"one\ntwo","b":"one\nthree"}'

RESPONSE (200)

{ "slug": "text-diff", "added": 1, "removed": 1, "unchanged": 1, "result": [{ "op": " ", "line": "one" }, ...] }

My IP (plain)

ipPOST /api/v1/tools/ip

Your public IP address and nothing else — also available as plain text via GET.

Parameter	Type	Default	Description
ip	string	—	Optional specific IP to look up (defaults to your own).

REQUEST

curl -X POST https://yas.sh/api/v1/tools/ip \
  -H "Content-Type: application/json" \
  -d '{}'

RESPONSE (200)

{ "slug": "ip", "result": "8.8.8.8" }  // GET returns bare text: 8.8.8.8

What Is My IP

what-is-my-ipPOST /api/v1/tools/what-is-my-ip

Your public IP with ASN, ISP, geo and VPN/Tor hints (ipinfo-style). No key needed.

Parameter	Type	Default	Description
ip	string	—	Optional specific IP to look up (defaults to your own via X-Real-IP / X-Forwarded-For). Also supported as ?ip= on GET.

REQUEST

curl -X POST https://yas.sh/api/v1/tools/what-is-my-ip \
  -H "Content-Type: application/json" \
  -d '{}'

RESPONSE (200)

{ "result": { "ip": "1.2.3.4", "ipv4": "1.2.3.4", "asn": "AS13335", "asName": "Cloudflare", "org": "Cloudflare", "city": "Lisbon", "region": "Lisbon", "country": "PT", "loc": "38.7167,-9.1333", "timezone": "Europe/Lisbon", "isVpn": null, "isTor": null } }

DNS Lookup

dns-lookupPOST /api/v1/tools/dns-lookup

Resolve A, AAAA, MX, TXT, NS, CNAME, SOA records for a domain (TTLs included).

Parameter	Type	Default	Description
input*	string	—	Domain, e.g. example.com (no scheme, no IP literals)
type	string	"all"	all \| A \| AAAA \| MX \| TXT \| NS \| CNAME \| SOA

REQUEST

curl -X POST https://yas.sh/api/v1/tools/dns-lookup \
  -H "Content-Type: application/json" \
  -d '{"input":"yas.sh"}'

RESPONSE (200)

{ "result": { "domain": "yas.sh", "A": [{ "address": "93.184.216.34", "ttl": 300 }], "MX": [{ "priority": 10, "exchange": "mx1.example.com" }], ... } }

IP Subnet Calculator

ip-subnet-calculatorPOST /api/v1/tools/ip-subnet-calculator

IPv4 CIDR math: network, broadcast, netmask, usable hosts.

Parameter	Type	Default	Description
input*	string	—	CIDR, e.g. 192.168.1.0/24

REQUEST

curl -X POST https://yas.sh/api/v1/tools/ip-subnet-calculator \
  -H "Content-Type: application/json" \
  -d '{"input":"192.168.1.0/24"}'

RESPONSE (200)

{ "result": { "valid": true, "network": "192.168.1.0", "broadcast": "192.168.1.255", "mask": "255.255.255.0", "hosts": 254, "prefix": 24 } }

TLS Analyzer

tls-analyzerPOST /api/v1/tools/tls-analyzer

Full TLS audit of a host: cert chain, expiry, SANs, protocol, cipher, OCSP stapling + HSTS header.

Parameter	Type	Default	Description
input*	string	—	Hostname, e.g. yas.sh (port via :443 form allowed)

REQUEST

curl -X POST https://yas.sh/api/v1/tools/tls-analyzer \
  -H "Content-Type: application/json" \
  -d '{"input":"yas.sh"}'

RESPONSE (200)

{ "result": { "authorized": true, "expiresInDays": 89, "sans": [...], "hsts": { "present": true, "maxAge": 63072000, "includeSubDomains": true, "preload": true }, ... } }

DANE / TLSA

dane-tlsaPOST /api/v1/tools/dane-tlsa

Validate DANE TLSA records (_port._tcp.domain) against the live TLS certificate.

Parameter	Type	Default	Description
input*	string	—	Hostname, e.g. example.com
port	integer	443	Service port (default 443)
proto	string	"tcp"	tcp \| udp

REQUEST

curl -X POST https://yas.sh/api/v1/tools/dane-tlsa \
  -H "Content-Type: application/json" \
  -d '{"input":"example.com","port":443,"proto":"tcp"}'

RESPONSE (200)

{ "result": { "records": [{ "raw": "3 1 1 abc...", "usage": 3, "selector": 1, "matchingType": 1, "match": true }], "cert": { "subject": "...", "expiresInDays": 120 } } }

SPF Inspector

spf-inspectorPOST /api/v1/tools/spf-inspector

Parse SPF (v=spf1): mechanisms, DNS-lookup count vs the 10 limit, ~all/-all, flattened IP count.

Parameter	Type	Default	Description
input*	string	—	Domain, e.g. example.com

REQUEST

curl -X POST https://yas.sh/api/v1/tools/spf-inspector \
  -H "Content-Type: application/json" \
  -d '{"input":"example.com"}'

RESPONSE (200)

{ "result": { "record": "v=spf1 ip4:1.2.3.4 include:_spf.example.com ~all", "lookupCount": 2, "lookupLimit": 10, "hasAll": true, "allValue": "~all", "permError": false, "flattenedIps": 6, "tree": [...] } }

DMARC Inspector

dmarc-inspectorPOST /api/v1/tools/dmarc-inspector

Fetch and validate _dmarc.<domain> TXT: policy badge, alignment, pct, rua/ruf.

Parameter	Type	Default	Description
input*	string	—	Domain, e.g. example.com

REQUEST

curl -X POST https://yas.sh/api/v1/tools/dmarc-inspector \
  -H "Content-Type: application/json" \
  -d '{"input":"example.com"}'

RESPONSE (200)

{ "result": { "found": true, "record": "v=DMARC1; p=reject; rua=mailto:dmarc@example.com", "policy": "reject", "subdomainPolicy": null, "pct": 100, "adkim": "r", "aspf": "r", "rua": ["dmarc@example.com"], "valid": true, "issues": [] } }

DKIM Inspector

dkim-inspectorPOST /api/v1/tools/dkim-inspector

Validate <selector>._domainkey.<domain> TXT: v=DKIM1, k=rsa, key length, t= flags.

Parameter	Type	Default	Description
input*	string	—	Domain, e.g. example.com
selector	string	"selector1"	DKIM selector

REQUEST

curl -X POST https://yas.sh/api/v1/tools/dkim-inspector \
  -H "Content-Type: application/json" \
  -d '{"input":"example.com","selector":"selector1"}'

RESPONSE (200)

{ "result": { "found": true, "record": "v=DKIM1; k=rsa; p=MIIB...", "keyLength": 2048, "flags": [], "valid": true } }

MX Health

mx-healthPOST /api/v1/tools/mx-health

MX audit: priorities, A/AAAA resolution, STARTTLS-era port-25 probe, null MX (RFC 7505), duplicates.

Parameter	Type	Default	Description
input*	string	—	Domain, e.g. example.com

REQUEST

curl -X POST https://yas.sh/api/v1/tools/mx-health \
  -H "Content-Type: application/json" \
  -d '{"input":"example.com"}'

RESPONSE (200)

{ "result": { "nullMx": false, "hosts": [{ "preference": 10, "exchange": "mx1.example.com", "ips": ["93.184.216.34"], "port25": { "open": true } }], "duplicatePriorities": [], "issues": [] } }

MTA-STS & TLS-RPT

mta-sts-tlsrptPOST /api/v1/tools/mta-sts-tlsrpt

MTA-STS (mta-sts TXT + /.well-known/mta-sts.txt) and TLS-RPT (_smtp._tls TXT) validation.

Parameter	Type	Default	Description
input*	string	—	Domain, e.g. example.com

REQUEST

curl -X POST https://yas.sh/api/v1/tools/mta-sts-tlsrpt \
  -H "Content-Type: application/json" \
  -d '{"input":"example.com"}'

RESPONSE (200)

{ "result": { "stsTxt": { "found": true, "id": "20260808", "valid": true }, "policy": { "found": true, "mode": "enforce", "maxAge": 86400, "mx": ["mx1.example.com"] }, "tlsrpt": { "found": true, "rua": ["tlsrpt@example.com"] }, "issues": [] } }

URL Parser

url-parserPOST /api/v1/tools/url-parser

Split any URL into protocol, auth, host, port, path, query (parsed), hash + origin.

Parameter	Type	Default	Description
input*	string	—	Any URL

REQUEST

curl -X POST https://yas.sh/api/v1/tools/url-parser \
  -H "Content-Type: application/json" \
  -d '{"input":"https://user:pass@example.com:8443/a/b?q=1#frag"}'

RESPONSE (200)

{ "result": { "protocol": "https:", "host": "example.com:8443", "hostname": "example.com", "port": "8443", "pathname": "/a/b", "query": { "q": "1" }, "hash": "#frag", "origin": "https://example.com:8443" } }

HTTP Status Codes

http-status-codesPOST /api/v1/tools/http-status-codes

Look up HTTP status codes by number or by searching names/classes.

Parameter	Type	Default	Description
input*	string	—	e.g. 404, or text like "gone" / "2xx"

REQUEST

curl -X POST https://yas.sh/api/v1/tools/http-status-codes \
  -H "Content-Type: application/json" \
  -d '{"input":"404"}'

RESPONSE (200)

{ "result": { "match": { "code": 404, "name": "Not Found", "class": "4xx Client Error", "meaning": "...", "useWhen": "..." } } }

Cron Parser

cron-parserPOST /api/v1/tools/cron-parser

Parse a 5/6-field cron expression and compute the next 5 run times (UTC).

Parameter	Type	Default	Description
input*	string	—	Cron expression, e.g. /15 * * *
count	integer	5	1–10 next runs

REQUEST

curl -X POST https://yas.sh/api/v1/tools/cron-parser \
  -H "Content-Type: application/json" \
  -d '{"input":"*/15 * * * *"}'

RESPONSE (200)

{ "result": { "valid": true, "expression": "*/15 * * * *", "next": ["2026-08-08T12:15:00.000Z", ...] } }

Color Converter

color-converterPOST /api/v1/tools/color-converter

Convert a color to HEX / RGB / HSL / CMYK / HSV + WCAG contrast ratios.

Parameter	Type	Default	Description
input*	string	—	#hex, rgb(), hsl(), or basic color name

REQUEST

curl -X POST https://yas.sh/api/v1/tools/color-converter \
  -H "Content-Type: application/json" \
  -d '{"input":"#6366f1"}'

RESPONSE (200)

{ "result": { "hex": "#6366f1", "rgb": "rgb(99, 102, 241)", "hsl": "hsl(239, 84%, 67%)", "contrastWhite": 4.87, "bestText": "white" } }

Number Base Converter

number-base-converterPOST /api/v1/tools/number-base-converter

Convert numbers between bases 2–36 (BigInt, arbitrary precision).

Parameter	Type	Default	Description
input*	string	—	Value in the source base
from	integer	10	Source base (2–36)
to	integer	16	Target base (2–36)

REQUEST

curl -X POST https://yas.sh/api/v1/tools/number-base-converter \
  -H "Content-Type: application/json" \
  -d '{"input":"255","from":10,"to":16}'

RESPONSE (200)

{ "result": { "input": "255", "from": 10, "to": 16, "value": "ff" } }

Markdown → HTML

markdown-to-htmlPOST /api/v1/tools/markdown-to-html

Render Markdown to sanitized HTML (marked + sanitize-html allow-list, XSS-safe).

Parameter	Type	Default	Description
input*	string	—	Markdown (≤ 64 KB)

REQUEST

curl -X POST https://yas.sh/api/v1/tools/markdown-to-html \
  -H "Content-Type: application/json" \
  -d '{"input":"# Hello\n\n**bold**"}'

RESPONSE (200)

{ "result": "<h1>Hello</h1>\n<p><strong>bold</strong></p>" }

CSV → JSON

csv-to-jsonPOST /api/v1/tools/csv-to-json

Parse CSV (quoted fields, headers) into a JSON array.

Parameter	Type	Default	Description
input*	string	—	CSV text (≤ 64 KB, ≤ 5,000 rows)
delimiter	string	","	Field delimiter
hasHeader	boolean	true	First row = keys

REQUEST

curl -X POST https://yas.sh/api/v1/tools/csv-to-json \
  -H "Content-Type: application/json" \
  -d '{"input":"name,age\nAnna,30\nBob,25"}'

RESPONSE (200)

{ "result": { "rows": [{ "name": "Anna", "age": "30" }], "count": 2, "columns": ["name", "age"] } }

Slug Generator

slug-generatorPOST /api/v1/tools/slug-generator

Turn any text into a URL-safe slug (transliterates Latin accents).

Parameter	Type	Default	Description
input*	string	—	Source text
separator	string	"-"	Word separator
maxLength	integer	80	Output cap

REQUEST

curl -X POST https://yas.sh/api/v1/tools/slug-generator \
  -H "Content-Type: application/json" \
  -d '{"input":"Hello, World! 2026"}'

RESPONSE (200)

{ "result": "hello-world-2026" }

Text Sorter

text-sorterPOST /api/v1/tools/text-sorter

Sort lines ascending / descending / natural, dedupe, or shuffle (CSPRNG).

Parameter	Type	Default	Description
input*	string	—	Multi-line text
mode	string	"asc"	asc \| desc \| natural \| unique \| shuffle

REQUEST

curl -X POST https://yas.sh/api/v1/tools/text-sorter \
  -H "Content-Type: application/json" \
  -d '{"input":"b\na\nc","mode":"asc"}'

RESPONSE (200)

{ "result": "a\nb\nc" }

Readability Score

readability-scorePOST /api/v1/tools/readability-score

Flesch Reading Ease + Flesch-Kincaid grade level + sentence/word stats.

Parameter	Type	Default	Description
input*	string	—	Any English text

REQUEST

curl -X POST https://yas.sh/api/v1/tools/readability-score \
  -H "Content-Type: application/json" \
  -d '{"input":"The quick brown fox jumps over the lazy dog."}'

RESPONSE (200)

{ "result": { "sentences": 1, "words": 9, "syllables": 11, "fleschReadingEase": 70.2, "gradeLevel": 6.2 } }

chmod Calculator

chmod-calculatorPOST /api/v1/tools/chmod-calculator

Convert between numeric (755) and symbolic (u=rwx,go=rx) permission modes, incl. special bits.

Parameter	Type	Default	Description
input*	string	—	e.g. 755, 4755, u=rwx,go=rx, or a+rwx

REQUEST

curl -X POST https://yas.sh/api/v1/tools/chmod-calculator \
  -H "Content-Type: application/json" \
  -d '{"input":"755"}'

RESPONSE (200)

{ "result": { "input": "755", "numeric": "755", "symbolic": "u=rwx,go=rx", "special": "none", "bits": { "owner": "rwx", "group": "r-x", "other": "r-x" } } }

Date Difference

date-differencePOST /api/v1/tools/date-difference

Difference between two dates: years/months/days/hours/minutes/seconds + business days.

Parameter	Type	Default	Description
a*	string	—	Date 1 (ISO or unix seconds)
b*	string	—	Date 2 (ISO or unix seconds)

REQUEST

curl -X POST https://yas.sh/api/v1/tools/date-difference \
  -H "Content-Type: application/json" \
  -d '{"a":"2026-01-01","b":"2026-08-08"}'

RESPONSE (200)

{ "result": { "milliseconds": ..., "days": 219, "weeks": 31, "businessDays": 156, "yearsApprox": 0.6 } }

Password Strength

password-strengthPOST /api/v1/tools/password-strength

Entropy estimate, crack-time (fast hash & bcrypt), and actionable feedback (zxcvbn-flavored).

Parameter	Type	Default	Description
input*	string	—	Password to evaluate

REQUEST

curl -X POST https://yas.sh/api/v1/tools/password-strength \
  -H "Content-Type: application/json" \
  -d '{"input":"Tr0ub4dor&3"}'

RESPONSE (200)

{ "result": { "score": 3, "length": 11, "entropyBits": 58.4, "crackFast": "4 days", "crackBcrypt": "102k years", "feedback": ["..."] } }

BROWSER-ONLY TOOLS

These tools are intentionally not available via the server API — their canonical implementation runs in the browser at /tools/:slug. The API returns{ clientOnly: true, reason } for them:

base64-file
Requires the browser File API.
xml-validator
Browser DOMParser, by design (no server XML parser bundled).
json-xml
Complex conversion runs client-side in the tool page.
csv-converter
Runs client-side — potentially sensitive data never uploaded.
sql-formatter
Runs client-side — SQL text must not leave your browser.
link-checker
Server-side would need outbound fetches to arbitrary URLs (SSRF risk).

Interactive API reference →OpenAPI 3.1 JSON Try the tools