Developer API

Run HTMLToolz from scripts, CI, and internal tools.

The paid API turns the browser toolbox into a dependable automation surface: format code, validate JSON, decode tokens, generate slugs, hash text, run batches, and sync extension data with one API key.

Create API key Compare paid plans Tool packs MCP connector

Tool runner

Use /api/v1/tools/run for one stable endpoint across supported tools.

Batch automation

Run multiple transforms in one request. Pro, Team, and Agency get graduated batch sizes.

Entitlements

/api/v1/me reports plan, limits, usage, and whether API/MCP access is active.

Tool packs and workflow recipes

Need a real starting point? Tool packs show the outcome, free tools, paid unlocks, API batch JSON, and matching MCP prompts for launch QA, payload cleanup, email HTML repair, and assistant context packs.

Open tool packs Workflow library

Test your API key

Runs in your browser against /api/v1/tools/run. Your key is only sent to HTMLToolz for this request and is not stored.

Response will appear here.

Authentication

Every paid API request needs your key in the Authorization header:

Authorization: Bearer htk_live_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Keys are shown once, stored as hashes, and can be revoked instantly from your account. GET /api/v1/me works for every valid key; transform endpoints return 403 when the account lacks API access.

Quick start

curl -X POST https://htmltoolz.com/api/v1/tools/run \
  -H "Authorization: Bearer htk_live_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"tool":"json-formatter","input":"{\"hello\":\"world\"}","options":{"minify":false}}'

{"ok":true,"tool":"json-formatter","output":"{\n    \"hello\": \"world\"\n}"}

Endpoints

Method	Endpoint	Purpose
GET	`/api/v1/me`	Plan, entitlements, and usage.
GET	`/api/v1/tools`	Supported paid API tool catalog.
POST	`/api/v1/tools/run`	Run one supported tool with `tool`, `input`, and optional `options`.
POST	`/api/v1/batch`	Run multiple tool operations in one request.
PUT	`/api/v1/ext/sync?kind=prompts`	Cloud sync storage for extension prompts.

Supported tools

json-formatterValidate, format, and minify JSON

html-formatterBeautify HTML

html-minifierCompact HTML

html-stripperHTML to plain text

html-entity-encoderEncode/decode entities

css-minifierCompact CSS

base64Encode/decode Base64

url-encoderEncode/decode URL components

jwt-decoderDecode JWT header and payload

hash-generatorGenerate SHA/MD5 hashes

slug-generatorCreate URL slugs

case-converterChange text casing

text-statisticsCount text metrics

uuid-generatorGenerate UUIDs

timestamp-converterUnix timestamp to ISO

Batch example

curl -X POST https://htmltoolz.com/api/v1/batch \
  -H "Authorization: Bearer htk_live_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"operations":[
    {"tool":"slug-generator","input":"Launch Notes: HTMLToolz API"},
    {"tool":"hash-generator","input":"release-v2","options":{"algorithm":"sha256"}},
    {"tool":"text-statistics","input":"One API. Many tools."}
  ]}'

Batch limits are plan-based: Pro handles quick scripts, Team handles shared workflows, and Agency handles higher-volume client automation.

Errors

Status	Meaning
`401`	Missing, invalid, or revoked API key.
`403`	The key is valid, but the account plan does not include this feature.
`413`	Request body or batch operation count is too large.
`422`	Bad input, unsupported tool, invalid JSON, or invalid tool options.
`429`	Daily API rate limit exceeded.