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Frequently Asked Questions (FAQ)

Find quick answers to the most common questions about API Codex. If you can't find what you're looking for, check our detailed documentation or contact support.

Getting Started

How do I get started with API Codex?

Getting started is simple:

  1. Sign up for a free account at dash.apicodex.io with just your email
  2. Create an API key from the API Keys page (acx_live_...)
  3. Browse the API Catalog to find the APIs you need
  4. Make your first call using our Getting Started guide
  5. Upgrade from dash.apicodex.io/billing when you outgrow the free plan

Do I need programming experience to use API Codex?

Basic programming knowledge is recommended. You should be familiar with:

  • Making HTTP requests in your programming language
  • Working with JSON data
  • Basic API concepts

Our documentation includes code examples in multiple languages to help you get started quickly.

Where can I find code examples?

Code examples are available in:

  • Our Getting Started guide with examples in JavaScript, Python, PHP, and cURL
  • The Authentication Guide with full request examples per language
  • Each API's documentation page in our API Catalog

Authentication & Security

How do I authenticate API requests?

All 40 API Codex APIs use one API key. Pass it as an X-Api-Key header:

Code
headers: { 'X-Api-Key': 'YOUR_API_KEY' }

Or as an apikey query parameter:

Code
https://api.apicodex.io/dns-lookup/v1/check?name=example.com&apikey=YOUR_API_KEY

Create your key at dash.apicodex.io. See our Authentication Guide for detailed examples.

Is my API key secure?

Your API key security depends on how you use it:

✅ Do:

  • Store keys in environment variables
  • Keep keys server-side only
  • Use secrets management (AWS Secrets Manager, Azure Key Vault)
  • Rotate keys regularly

❌ Don't:

  • Expose keys in client-side code
  • Commit keys to version control
  • Share keys publicly
  • Hard-code keys in your application

Can I rotate my API key?

Yes. You can keep up to 5 active keys in the dashboard: create a new key, switch your deployment over, then revoke the old one. Revocation takes effect within about a minute. Rotating keys periodically is good practice, especially if a key may have been compromised.

What should I do if my API key is exposed?

If your API key is exposed:

  1. Immediately create a new key in the dashboard
  2. Update your application with the new key
  3. Revoke the old key
  4. Review recent usage and credit consumption for any suspicious activity
  5. Audit your code to prevent future exposure

Pricing & Billing

Is there a free tier available?

Yes! Every account starts on the Free plan, perfect for:

  • Testing and development
  • Proof of concept projects
  • Small applications
  • Learning and experimentation

The Free plan includes 1,000 credits per month at 2 requests per second, with no credit card required.

What are the pricing tiers?

One plan covers all 40 APIs:

  • Free ($0) - 1,000 credits/month, 2 requests per second
  • Starter ($29.99/mo) - 50,000 credits/month, 10 requests per second, email support
  • Pro ($99.99/mo) - 250,000 credits/month, 25 requests per second, priority support

Requests are metered in credits: 1 credit for bundled data and edge lookups, 5 for live network lookups, and 25 for AI and scraping APIs. See current pricing at dash.apicodex.io/billing.

How am I billed for API usage?

Billing is handled in the dashboard:

  • Unified billing - One invoice covering all 40 API Codex APIs
  • Monthly subscription - Billed monthly based on your plan
  • One credit pool - Spend your monthly credits across any of the APIs
  • Transparent pricing - Plan limits and credit costs visible before you subscribe

Can I upgrade or downgrade my plan?

Yes, you can change your plan at any time from dash.apicodex.io/billing. Changes take effect immediately, billing is prorated, and your API key stays the same so no code changes are needed.

What happens if I exceed my rate limit?

If you exceed your rate limit:

  • The API returns a 429 Too Many Requests error
  • You can either wait for your quota to reset (typically monthly)
  • Or upgrade to a higher tier for more requests

Implement proper rate limit handling in your code to manage this gracefully. See our Rate Limiting guide.

API Usage

What APIs does API Codex offer?

API Codex provides several categories of APIs:

Email Services:

  • Email Intelligence API
  • Email Deliverability API
  • Email Parser API

Document Parsers:

  • Resume Parser API
  • Invoice Parser API
  • Receipt Parser API
  • Skill Parser API

Text Intelligence:

  • Text Analysis API
  • Text Anonymization API

Infrastructure:

  • DNS Lookup API
  • SERP API

Browse all APIs in our API Catalog.

Can I use multiple APIs with one key?

Yes! One key works across all 40 API Codex APIs. Just change the path segment in the base URL:

Code
// DNS API 'https://api.apicodex.io/dns-lookup/v1/check?name=example.com' // Email API 'https://api.apicodex.io/email-intelligence/v1/check?email=jane@startup.io'

The same X-Api-Key header (or apikey query parameter) authenticates every one of them.

What data formats do you support?

  • Request formats: JSON, query parameters, form data (varies by endpoint)
  • Response format: JSON (all APIs)
  • Character encoding: UTF-8
  • Date format: ISO 8601 (YYYY-MM-DDTHH:mm)

Do you offer batch processing?

Some APIs support batch processing, allowing you to process multiple items in a single request. Check each API's documentation for batch capabilities and limits.

What's the maximum request size?

Maximum request sizes vary by API and subscription tier:

  • Free tier: Typically 1-5 MB
  • Paid tiers: Up to 10-50 MB

Large files may require asynchronous processing. Check your specific API's documentation for exact limits.

Rate Limiting

What are the rate limits?

Rate limits are set by your plan and apply across all 40 APIs:

PlanCredits/MonthRequests/Second
Free1,0002
Starter50,00010
Pro250,00025

Each request costs 1, 5, or 25 credits depending on the API. See the Rate Limiting guide for details.

How can I check my current usage?

Monitor your usage through:

  • Dashboard - Real-time usage and remaining credits at dash.apicodex.io
  • Response headers - x-ratelimit-* headers in API responses
  • Per-key breakdown - See which key is consuming your credits

What happens when I hit the rate limit?

When you exceed your rate limit:

  • API returns HTTP 429 Too Many Requests
  • Response includes Retry-After header
  • Your quota resets at the start of the next billing period

Implement retry logic with exponential backoff to handle rate limits gracefully.

How can I optimize my API usage?

To stay within rate limits:

  • Cache responses based on TTL values
  • Batch requests when supported
  • Implement request queuing to control request rate
  • Use webhooks instead of polling
  • Monitor usage regularly

See our Best Practices guide for optimization strategies.

Error Handling

What error codes might I encounter?

Common error codes:

CodeMeaningSolution
400Bad RequestCheck request parameters
401UnauthorizedVerify API key
403ForbiddenCheck that your key is active and your plan covers the endpoint
404Not FoundVerify endpoint URL
429Too Many RequestsImplement rate limiting
500Server ErrorRetry with backoff
503Service UnavailableRetry later

How should I handle errors?

Best practices for error handling:

  1. Catch all errors - Don't let errors crash your app
  2. Log errors - Track issues for debugging
  3. Implement retries - Use exponential backoff for transient errors
  4. Set timeouts - Don't wait indefinitely
  5. Provide fallbacks - Handle graceful degradation

See our comprehensive Error Handling guide.

Why am I getting 401 Unauthorized errors?

Common causes:

  • Missing or incorrect API key
  • API key not in the correct header (X-Api-Key) or query parameter (apikey)
  • Extra whitespace copied in with the key
  • Revoked API key

Solution: Verify the header or query parameter is set correctly, and check the key's status in the dashboard.

Why am I getting 403 Forbidden errors?

Common causes:

  • Revoked or deleted API key
  • Endpoint not available on your current plan
  • Account suspended

Solution: Check your key status and plan in the dashboard. If it looks correct, contact support.

Integration

What programming languages are supported?

API Codex APIs are RESTful and work with any language that can make HTTP requests:

  • JavaScript/Node.js
  • Python
  • PHP
  • Ruby
  • Java
  • Go
  • C#/.NET
  • Swift
  • Kotlin
  • And many more

Every endpoint in the API Catalog ships with copy-paste snippets in cURL, JavaScript, Python, and PHP.

Can I use API Codex with my framework?

Yes! API Codex works with all web frameworks:

  • Frontend: React, Vue, Angular (via backend proxy)
  • Backend: Express, Django, Flask, Laravel, Rails, Spring Boot, etc.
  • Serverless: AWS Lambda, Azure Functions, Google Cloud Functions
  • Mobile: React Native, Flutter, native iOS/Android

Where can I test the APIs before integration?

Test APIs using:

  • Interactive playground - Try any endpoint in your browser from the API Catalog
  • Postman - Import the OpenAPI spec for any API
  • cURL - Command-line testing
  • Our examples - Copy and modify code snippets

Do you provide SDKs?

Not yet. Every API is a plain REST endpoint with an OpenAPI spec you can feed to your own generator, and the docs include ready-to-use snippets in cURL, JavaScript, Python, and PHP.

Can I use API Codex in a mobile app?

Yes, but follow these guidelines:

  • Never expose API keys in mobile apps
  • Always use a backend proxy/API gateway
  • Make API calls from your backend, not directly from the app
  • Your backend should validate requests and forward them to API Codex

Technical Questions

What's the API uptime/SLA?

API Codex runs on Cloudflare's global edge network:

  • Uptime: 99.9% target
  • Global availability from the edge location nearest your users
  • Auto-scaling to handle traffic spikes
  • Status monitoring available in your dashboard

What regions are APIs available in?

API Codex APIs are available globally from Cloudflare's edge network, so requests are served from the location nearest your users regardless of where you are.

Do you support webhooks?

Webhook support varies by API. Some APIs support:

  • Callback URLs for asynchronous operations
  • Event notifications for specific triggers
  • Result delivery via POST requests

Check individual API documentation for webhook capabilities.

Can I make requests from the browser (CORS)?

For security reasons, API keys should never be exposed in browser code. Instead:

  • Create a backend proxy endpoint
  • Make API calls from your server
  • Return sanitized results to your frontend

This protects your API key and provides better security.

What's the API response time?

Response times vary by API and complexity:

  • Simple lookups (DNS, email validation): 100-500ms
  • Parsing operations: 1-5 seconds
  • Complex analysis: 5-30 seconds

Actual times depend on request complexity, payload size, and network conditions.

Can I cache API responses?

Yes, caching is encouraged for:

  • Reducing API calls
  • Improving performance
  • Staying within rate limits

Implement caching based on:

  • TTL values in DNS responses
  • Data volatility
  • Your application's needs

See our Best Practices guide for caching strategies.

Support & Resources

Where can I get help?

Multiple support channels are available:

  • Documentation - Comprehensive guides at docs.apicodex.io
  • Contact Support - apicodex.io/contact for technical questions
  • Dashboard - Keys, usage, and billing at dash.apicodex.io
  • Code Examples - Available in all documentation
  • Email Support - Included on Starter and Pro plans

How do I report a bug?

To report bugs:

  1. Check if the issue is already known
  2. Gather error messages and request details
  3. Contact support
  4. Provide reproduction steps if possible

Can I request new features?

Yes! We welcome feature requests:

  • Submit through our contact form
  • Describe your use case
  • Explain the expected behavior
  • Priority given to requests from paid plans

Where is the API status page?

Monitor API status through:

  • Your dashboard, which shows recent request health
  • Response headers indicating health
  • The per-API /health endpoints where available

Do you offer enterprise support?

Yes, enterprise support is available:

  • Custom plans above the Pro tier for high-volume usage
  • Dedicated account management for large deployments
  • Custom SLAs available upon request
  • Integration assistance from our team

Contact us for enterprise inquiries.

Still Have Questions?

Can't find the answer you're looking for? Here are additional resources:

  • Getting Started - Quick start guide
  • API Catalog - Complete API documentation
  • Authentication Guide - Security and API keys
  • Best Practices - Production tips
  • Glossary - Technical term definitions
  • Contact Support - Direct support

For specific technical questions, consult the detailed documentation for your API in our API Catalog.

Last modified on August 9, 2026
Best PracticesGlossary
On this page
  • Getting Started
    • How do I get started with API Codex?
    • Do I need programming experience to use API Codex?
    • Where can I find code examples?
  • Authentication & Security
    • How do I authenticate API requests?
    • Is my API key secure?
    • Can I rotate my API key?
    • What should I do if my API key is exposed?
  • Pricing & Billing
    • Is there a free tier available?
    • What are the pricing tiers?
    • How am I billed for API usage?
    • Can I upgrade or downgrade my plan?
    • What happens if I exceed my rate limit?
  • API Usage
    • What APIs does API Codex offer?
    • Can I use multiple APIs with one key?
    • What data formats do you support?
    • Do you offer batch processing?
    • What's the maximum request size?
  • Rate Limiting
    • What are the rate limits?
    • How can I check my current usage?
    • What happens when I hit the rate limit?
    • How can I optimize my API usage?
  • Error Handling
    • What error codes might I encounter?
    • How should I handle errors?
    • Why am I getting 401 Unauthorized errors?
    • Why am I getting 403 Forbidden errors?
  • Integration
    • What programming languages are supported?
    • Can I use API Codex with my framework?
    • Where can I test the APIs before integration?
    • Do you provide SDKs?
    • Can I use API Codex in a mobile app?
  • Technical Questions
    • What's the API uptime/SLA?
    • What regions are APIs available in?
    • Do you support webhooks?
    • Can I make requests from the browser (CORS)?
    • What's the API response time?
    • Can I cache API responses?
  • Support & Resources
    • Where can I get help?
    • How do I report a bug?
    • Can I request new features?
    • Where is the API status page?
    • Do you offer enterprise support?
  • Still Have Questions?
Javascript
Javascript