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The Alter API Router is an OpenAI-compatible API gateway that provides unified access to 92+ AI models from 10+ providers through a single endpoint.

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What is the API Router?

The API Router is a centralized service that eliminates the need to manage multiple API keys and billing accounts across different AI providers. Instead of maintaining separate accounts with OpenAI, Anthropic, Google, and others, you can use Alter as your single entry point for all AI model access.

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Key Benefits

  • Single API key for all providers
  • Centralized billing through your Alter account
  • 92+ models from 10+ providers
  • OpenAI-compatible endpoint works with existing tools and SDKs
  • Easy model switching without code changes

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Quick Start

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1. Generate an API Key

  1. Open Settings (⌘ ,)
  2. Go to the Router tab
  3. Under “Alter API Keys”, click Add New Key
  4. Copy your key (starts with sk-)

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2. Get the Endpoint

https://alterhq.com/api
For most tools, use: 
https://alterhq.com/api/v1

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3. List Available Models

curl https://alterhq.com/api/models \
  -H "Authorization: Bearer YOUR_API_KEY"

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Model Naming Format

Models use the format: Provider#Model-name Examples:
  • OpenAI#gpt-5 - Latest GPT-5
  • OpenAI#gpt-5-mini - Lightweight GPT-5
  • Claude#claude-sonnet-4-6 - Latest Claude
  • Gemini#gemini-2.5-pro - Latest Gemini

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Usage Example

from openai import OpenAI

client = OpenAI(
    api_key="YOUR_API_KEY",
    base_url="https://alterhq.com/api/v1"
)

response = client.chat.completions.create(
    model="OpenAI#gpt-5",
    messages=[
        {"role": "user", "content": "What is machine learning?"}
    ]
)

print(response.choices[0].message.content)

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Usage Limits

  • Daily Limit: 200 requests per day under fair use
  • Throttling: After 200 requests, throttled to 1 per 10 minutes
  • Budget Top-up: Available for consistent access beyond fair use

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Next Steps