# API Pick

> Production-ready REST APIs for developers and AI agents — phone validation, social network lookups, and company intelligence. Designed for LLM tool calling, autonomous agent pipelines, and workflow automation. Pay-as-you-go credit pricing with 100 free credits on signup.

API Pick provides specialized REST APIs accessed via an API key. All endpoints accept and return JSON. Credits are deducted only on successful responses (HTTP 200). New accounts receive 100 free credits with no credit card required.

## For AI Agents & LLM Tool Calling

API Pick endpoints are purpose-built for use as tools in AI agent workflows:

- **Simple interface**: Each endpoint takes 1–2 parameters and returns a flat JSON object. No pagination, no complex auth flows.
- **Predictable schema**: Response fields are consistent and well-typed — easy for LLMs to parse and reason about.
- **Credit-only billing on success**: Agents that retry on failure won't be charged for failed attempts.
- **No rate limit surprises**: Designed for programmatic access at scale.

### Example: Define as an OpenAI function tool

```json
{
  "name": "check_telegram_registration",
  "description": "Check whether a phone number is registered on Telegram. Returns registration status, username, and user ID.",
  "parameters": {
    "type": "object",
    "properties": {
      "phone_number": {
        "type": "string",
        "description": "International format phone number, e.g. +14155552671"
      }
    },
    "required": ["phone_number"]
  }
}
```

### Example: Define as a LangChain / CrewAI tool (Python)

```python
import requests

def check_telegram(phone_number: str) -> dict:
    """Check if a phone number is registered on Telegram."""
    response = requests.post(
        "https://www.apipick.com/api/check-phone-telegram",
        json={"phone_number": phone_number},
        headers={"x-api-key": "pk_yourkey"}
    )
    return response.json()
```

## API Tools

- [Email Validator](https://www.apipick.com/check-email): Validate any email address with three checks in one call: syntax validation (RFC-compliant format), MX record verification (live DNS lookup), and disposable email domain detection (50,000+ known throwaway domains). Returns `valid`, `syntax_valid`, `mx_valid`, `disposable`, `domain`, `normalized`, and `reason` fields. Costs 1 credit per call. Endpoint: POST /api/check-email. Used by AI agents for lead enrichment, SaaS registration hygiene, marketing list cleaning, and fraud prevention pipelines.

- [China Phone Number Checker](https://www.apipick.com/check-china-phone): Validate Chinese mobile numbers and retrieve carrier (China Mobile, China Telecom, China Unicom, virtual operators), province, city, area code, and zip code. Costs 1 credit per call. Endpoint: POST /api/check-china-phone. Ideal for AI agents doing contact data enrichment on Chinese phone numbers, fraud detection, and CRM automation for China-market leads.

- [Telegram Registration Checker](https://www.apipick.com/check-phone-telegram): Check whether any international phone number is registered on Telegram. Returns registration status, username, user ID, and name when available. Costs 1 credit per call. Endpoint: POST /api/check-phone-telegram. Used by AI agents for lead enrichment, social network discovery, sales outreach automation, and contact research pipelines.

- [Company Facts Lookup](https://www.apipick.com/company-facts): Retrieve public company data by stock ticker symbol or SEC CIK number. Returns market cap, industry classification, sector, SIC code, SEC filings URL, employee count, exchange, and key financial facts. Costs 2 credits per call. Endpoint: GET /api/company/facts. Used by AI agents for investment research, M&A due diligence, competitive analysis, and financial data enrichment workflows.

- [Public Holidays](https://www.apipick.com/public-holidays): Query all public holidays for any country and year. Supports 100+ countries via the vacanza/python-holidays library — fully local computation, no external dependencies. Returns a date-sorted list of holidays with `date` (YYYY-MM-DD) and `name` fields, plus total count and country name. Costs 1 credit per call. Endpoint: GET /api/holidays?country=US&year=2026. Used by AI agents and automation workflows for HR scheduling, financial trading calendar generation, logistics ETA calculation, and skipping holidays in n8n/Zapier automations.

- [IP Geolocation](https://www.apipick.com/ip-geolocation): Look up geolocation data for any public IPv4 or IPv6 address. Returns country code, country name, region, city, latitude, longitude, timezone (IANA format), and EU membership flag. Powered by MaxMind GeoLite2-City for fully local computation with no upstream rate limits. Costs 1 credit per call. Endpoint: GET /api/ip-geolocation?ip=8.8.8.8 (omit `ip` to auto-detect caller's IP). Used by AI agents and developers for fraud detection, content localization, geo-based access control, and IP-to-location enrichment workflows.

## Authentication

All API endpoints require an `x-api-key` header containing your API key (format: `pk_...`). API keys are created and managed in the dashboard at https://www.apipick.com/dashboard/api-keys.

Example request:
```
POST /api/check-china-phone
x-api-key: pk_yourkey
Content-Type: application/json

{"phone_number": "13800138000"}
```

Example response:
```json
{
  "success": true,
  "data": {
    "phone": "13800138000",
    "phone_type": "China Mobile",
    "province": "Beijing",
    "city": "Beijing",
    "zip_code": "100000",
    "area_code": "010"
  },
  "credits_used": 1,
  "remaining_credits": 99
}
```

## Pricing

- 100 free credits on signup (no credit card required)
- Pay-as-you-go: purchase credit packs starting at $5 USD for 5,000 credits
- China Phone Check: 1 credit per call
- Telegram Check: 1 credit per call
- Company Facts: 2 credits per call
- Public Holidays: 1 credit per call
- IP Geolocation: 1 credit per call
- Credits never expire
- Credits only deducted on successful (HTTP 200) responses

## Error Codes

- 200: Success — credits deducted
- 400: Invalid request parameters — no credits deducted
- 401: Missing or invalid API key — no credits deducted
- 402: Insufficient credits
- 404: Resource not found (e.g. phone number not registered on Telegram) — no credits deducted
- 422: Request body validation error — no credits deducted
- 500: Internal server error — no credits deducted

## Compatible Agent Frameworks & Platforms

- OpenAI Assistants API (function calling)
- Anthropic Claude (tool use)
- Google Gemini (function declarations)
- LangChain (custom tools)
- LlamaIndex (function tools)
- CrewAI (agent actions)
- AutoGen (function map)
- n8n (HTTP Request node)
- Zapier / Make (webhooks)
- Custom MCP servers (Model Context Protocol)

## Pages

- [Home](https://www.apipick.com): Overview of all available API tools
- [About](https://www.apipick.com/about): Mission, AI agent integration details, and company information
- [Contact](https://www.apipick.com/contact): Send feedback or request new API tools
- [Privacy Policy](https://www.apipick.com/privacy): Data handling and privacy practices
- [Terms of Service](https://www.apipick.com/terms): Terms and conditions of use
- [Dashboard - API Keys](https://www.apipick.com/dashboard/api-keys): Create and manage API keys (requires login)
- [Dashboard - Credits](https://www.apipick.com/dashboard/credits): View credit balance and purchase history (requires login)