Public API

Free REST API for developer utilities. CORS-enabled, JSON responses, no browser required. Perfect for scripts, CI pipelines, and side projects.

Quick Start

1. Get a free API key

curl -X POST https://devplaybook.cc/api/keys \
  -H "Content-Type: application/json" \
  -d '{"email": "[email protected]"}'

# Response:
# {"apiKey":"dp_abc123...","plan":"free","limits":{"requestsPerDay":100}}

2. Make your first request

curl "https://devplaybook.cc/api/v1/uuid" \
  -H "X-API-Key: dp_your_key_here"

# Response:
# {"uuids":["550e8400-e29b-41d4-a716-446655440000"],"count":1}

Rate Limits

Free Plan
100 requests/day per key
Resets at midnight UTC
Pro Plan
1,000 requests/day per key
Upgrade to Pro →

Rate limit headers returned on every response: X-RateLimit-Remaining, X-RateLimit-Limit, X-RateLimit-Plan

Endpoints

GET /api/v1/uuid

Generate one or more UUID v4 values.

QUERY PARAMS
countNumber of UUIDs (default: 1, max: 10 free / 100 pro)
curl "https://devplaybook.cc/api/v1/uuid?count=3" \
  -H "X-API-Key: dp_your_key"
# {"uuids":["...","...","..."],"count":3}
GET /api/v1/cron

Validate and describe a cron expression in plain English.

QUERY PARAMS
expression5-field cron expression (URL-encoded)
curl "https://devplaybook.cc/api/v1/cron?expression=0+9+*+*+1-5" \
  -H "X-API-Key: dp_your_key"
# {"valid":true,"summary":"Run at 9:00 AM, Monday through Friday",...}
POST /api/v1/json-format

Format, minify, or validate JSON. Max 100KB (free) / 1MB (pro).

BODY (JSON)
jsonJSON string to format (required)
indentIndent size (default: 2)
minifySet true to minify instead
curl -X POST https://devplaybook.cc/api/v1/json-format \
  -H "X-API-Key: dp_your_key" \
  -H "Content-Type: application/json" \
  -d '{"json":"{\"name\":\"alice\",\"age\":30}","indent":4}'
# {"valid":true,"formatted":"{\n    \"name\": \"alice\"...}"}
POST /api/v1/regex

Test, match, or apply a regex pattern against input text.

BODY (JSON)
patternRegex pattern string (required)
flagsRegex flags, e.g. "gi" (optional)
inputText to test against
operation"test" | "match" | "replace" (default: match)
replacementReplacement string (for "replace" operation)
curl -X POST https://devplaybook.cc/api/v1/regex \
  -H "X-API-Key: dp_your_key" \
  -H "Content-Type: application/json" \
  -d '{"pattern":"\\b\\w+@\\w+\\.\\w+\\b","flags":"g","input":"contact [email protected] or [email protected]","operation":"match"}'
# {"matchCount":2,"matches":[{"match":"[email protected]","index":8},...]}
POST /api/v1/token-count

Estimate token count and per-model AI API cost for any text.

BODY (JSON)
textText to analyze (free: 10K chars, pro: 100K chars)
curl -X POST https://devplaybook.cc/api/v1/token-count \
  -H "X-API-Key: dp_your_key" \
  -H "Content-Type: application/json" \
  -d '{"text":"Hello, world!"}'
# {"tokens":4,"words":2,"chars":13,"model_estimates":{"gpt-4o":{"estimated_cost_usd":0.00001,...}}}
GET /api/v1/ai-price

Calculate AI API cost for any model and token count. Pro: batch compare all models.

QUERY PARAMS
modelModel name (e.g. gpt-4o, claude-3-5-sonnet)
input_tokensNumber of input tokens
output_tokensNumber of output tokens (optional)
curl "https://devplaybook.cc/api/v1/ai-price?model=gpt-4o&input_tokens=1000&output_tokens=500" \
  -H "X-API-Key: dp_your_key"
# {"model":"gpt-4o","cost_usd":0.007500,"breakdown":{"input_cost_usd":0.0025,...}}
POST /api/v1/word-count

Count words, sentences, paragraphs, and reading time for any text.

BODY (JSON)
textText to analyze (free: 50K chars, pro: 500K chars)
curl -X POST https://devplaybook.cc/api/v1/word-count \
  -H "X-API-Key: dp_your_key" \
  -H "Content-Type: application/json" \
  -d '{"text":"Hello world. This is a test."}'
# {"words":6,"chars":29,"sentences":2,"paragraphs":1,"reading_time_min":0.0}
GET /api/user-subscription

Check Pro subscription status by email. No API key required.

curl "https://devplaybook.cc/api/[email protected]"
# {"isPro":true,"plan":"pro","status":"active","subscribedAt":"2026-03-20T..."}

Get Your Free API Key

100 requests/day, no credit card required.