AI Provider Configuration

Overview

Sunschool supports multiple AI providers with automatic fallback chains. From server/services/ai.ts:

import {
  askOpenRouter as chatOpenRouter,
  generateLessonContent as generateLessonContentOpenRouter,
  generateQuizQuestions as generateQuizQuestionsOpenRouter
} from "../openrouter";

import {
  askBittensor as chatBittensor,
  generateLessonContent as generateLessonContentBittensor
} from "../bittensor";

import { LLM_PROVIDER } from '../config/env';
import { ENABLE_BITTENSOR_SUBNET_1, BITTENSOR_FALLBACK_ENABLED } from '../config/flags';

Provider Selection

From server/services/ai.ts:

export const getLLMProvider = () => {
  const configured = process.env.LLM_PROVIDER?.toLowerCase() || 'openrouter';

  // Only allow Bittensor if explicitly enabled
  if (configured === 'bittensor' && !ENABLE_BITTENSOR_SUBNET_1) {
    console.warn('Bittensor requested but not enabled. Falling back to OpenRouter.');
    return 'openrouter';
  }

  return configured;
};

OpenRouter (Primary)

OpenRouter is the recommended primary provider. It provides access to multiple models including GPT-4, Claude, and Gemini.

Setup

Create Account

Add Credits

Navigate to Credits and add balance ($5-10 recommended for testing)

Generate API Key

Go to Keys and create a new API key

Configure Environment

OPENROUTER_API_KEY="sk-or-v1-1234567890abcdef..."

Models Used

From server/config/env.ts:

export const OPENROUTER_IMAGE_MODEL = process.env.OPENROUTER_IMAGE_MODEL || 'google/gemini-3.1-pro-preview';
export const OPENROUTER_SVG_MODEL = process.env.OPENROUTER_SVG_MODEL || 'google/gemini-3.1-pro-preview';

Default models:

Purpose	Model	Why
Lesson content	`google/gemini-3.1-pro-preview`	High-quality long-form content
Quiz generation	`google/gemini-3.1-pro-preview`	Strong reasoning for question creation
SVG illustrations	`google/gemini-3.1-flash-lite-preview`	Fast, cost-effective visual generation

Model Customization

Override default models:

OPENROUTER_IMAGE_MODEL=anthropic/claude-3.5-sonnet
OPENROUTER_SVG_MODEL=google/gemini-3.1-flash-lite-preview

Available models at openrouter.ai/models.

Fallback Chains

From server/config/env.ts:

export const SVG_MODEL_FALLBACKS: string[] = (process.env.SVG_MODEL_FALLBACKS || '')
  .split(',').map(s => s.trim()).filter(Boolean);

export const DEFAULT_SVG_MODEL_FALLBACKS = [
  'google/gemini-3.1-flash-lite-preview',
  'google/gemini-3-flash-preview',
];

Configure fallbacks:

SVG_MODEL_FALLBACKS="google/gemini-3.1-flash-lite-preview,google/gemini-3-flash-preview,anthropic/claude-3-haiku"

From ENGINEERING.md:

Model fallback chain: primary model → fallbacks from SVG_MODEL_FALLBACKS env → built-in defaults. Models returning 402 (insufficient credits) or 404 are automatically skipped.

Rate Limits & Costs

Monitor your OpenRouter usage at openrouter.ai/activity to avoid unexpected charges.

Approximate costs (as of 2026):

Model	Input (per 1M tokens)	Output (per 1M tokens)
Gemini 3.1 Pro	$2.50	$10.00
Gemini 3.1 Flash	$0.075	$0.30
Claude 3.5 Sonnet	$3.00	$15.00

Typical lesson generation:

Input: ~2,000 tokens (prompts + context)
Output: ~3,000 tokens (lesson content)
Cost per lesson: ~$0.05-0.10

Perplexity (Knowledge Enrichment)

Perplexity enhances lessons with up-to-date information and context. Optional but recommended.

Setup

Create Account

Access API

Navigate to API Settings

Generate Key

Create API key (starts with pplx-)

Configure

PERPLEXITY_API_KEY="pplx-1234567890abcdef..."

Use Cases

From ENGINEERING.md:

Perplexity - Knowledge context enrichment

Perplexity is used to:

Add current events to history lessons
Provide real-world examples for math/science
Enrich content with recent research

Example integration:

// Conceptual usage in lesson enrichment
const context = await perplexity.search(topic);
const lesson = await generateLessonWithContext(topic, context);

Bittensor Subnet 1 (Experimental)

Bittensor integration is experimental. Use OpenRouter for production deployments.

From ENGINEERING.md:

Status: Client and config implemented (Phases 1-3 complete). Testing/validation (Phase 4) and production deployment (Phase 5) pending.

What is Bittensor?

Bittensor is a decentralized AI network where miners compete to provide LLM inference. Subnet 1 specializes in text generation. Benefits:

Decentralized (no single point of failure)
Competitive pricing
Open and auditable

Limitations:

Still experimental for production
Variable response times
Requires wallet setup

Setup

Install Bittensor

pip install bittensor

Create Wallet

btcli wallet new_coldkey --wallet.name my_wallet
btcli wallet new_hotkey --wallet.name my_wallet --wallet.hotkey my_hotkey

Get API Key

Follow Bittensor documentation for API access

Configure Environment

ENABLE_BITTENSOR_SUBNET_1=1
BITTENSOR_API_KEY="your-bittensor-key"
BITTENSOR_WALLET_NAME="my_wallet"
BITTENSOR_WALLET_HOTKEY="my_hotkey"
BITTENSOR_SUBNET_1_URL="https://archive.opentensor.ai/graphql"

Enable as Primary Provider

From server/config/env.ts:

export const LLM_PROVIDER = process.env.LLM_PROVIDER || 'openrouter';
export const BITTENSOR_API_KEY = process.env.BITTENSOR_API_KEY || '';
export const BITTENSOR_SUBNET_1_URL = process.env.BITTENSOR_SUBNET_1_URL || 'https://archive.opentensor.ai/graphql';

Set as primary:

LLM_PROVIDER=bittensor
ENABLE_BITTENSOR_SUBNET_1=1
BITTENSOR_FALLBACK_ENABLED=1

From ENGINEERING.md:

# Enable Bittensor as primary provider
export ENABLE_BITTENSOR_SUBNET_1=1
export LLM_PROVIDER=bittensor
export BITTENSOR_API_KEY=your_key
export BITTENSOR_WALLET_NAME=your_wallet
export BITTENSOR_WALLET_HOTKEY=your_hotkey
export BITTENSOR_FALLBACK_ENABLED=1  # fallback to OpenRouter

Automatic Fallback

From server/services/ai.ts:

export const chat = async (options: any): Promise<BittensorResponse> => {
  const provider = getLLMProvider();

  if (provider === 'bittensor') {
    try {
      return await chatBittensor(options);
    } catch (error) {
      console.error('Bittensor chat failed:', error);
      if (BITTENSOR_FALLBACK_ENABLED) {
        console.log('Falling back to OpenRouter');
        return await chatOpenRouter(options);
      }
      throw error;
    }
  }

  return await chatOpenRouter(options);
};

Enable fallback:

BITTENSOR_FALLBACK_ENABLED=1

From server/config/flags.ts:

export const BITTENSOR_FALLBACK_ENABLED = process.env.BITTENSOR_FALLBACK_ENABLED !== '0';

Feature Flags

Global AI Toggle

From server/config/flags.ts:

export const USE_AI = process.env.USE_AI !== '0';

Disable all AI features:

USE_AI=0

This uses static fallback content instead of AI generation. Useful for:

Testing without API costs
Offline development
Debugging non-AI features

Image Generation Controls

export const ENABLE_SVG_LLM = process.env.ENABLE_SVG_LLM !== '0';
export const ENABLE_OPENROUTER_IMAGES = process.env.ENABLE_OPENROUTER_IMAGES !== '0';
export const ENABLE_STABILITY_FALLBACK = process.env.ENABLE_STABILITY_FALLBACK === '1';

Configuration:

ENABLE_SVG_LLM=1                # LLM-generated SVG illustrations
ENABLE_OPENROUTER_IMAGES=1      # Raster images via OpenRouter
ENABLE_STABILITY_FALLBACK=0     # Stability AI (requires separate key)

Image Provider Selection

From server/config/env.ts:

export const IMAGE_PROVIDER = process.env.IMAGE_PROVIDER || 'svg-llm';

Options:

svg-llm (Default)
openrouter
stability

IMAGE_PROVIDER=svg-llm
OPENROUTER_SVG_MODEL=google/gemini-3.1-pro-preview
MAX_IMAGES_PER_LESSON=4

Generates clean SVG illustrations
Small file sizes (~10-50 KB)
Works offline after generation
Best for diagrams and educational graphics

IMAGE_PROVIDER=openrouter
OPENROUTER_IMAGE_MODEL=google/gemini-3.1-flash-image-preview

Generates raster images (PNG/JPEG)
More photorealistic
Larger file sizes
Requires model with vision capabilities

IMAGE_PROVIDER=stability
STABILITY_API_KEY=sk-...

Uses Stability AI (Stable Diffusion)
High-quality photorealistic images
Separate API key required

Image Generation Timeouts

export const IMAGE_GENERATION_TIMEOUT = parseInt(process.env.IMAGE_GENERATION_TIMEOUT || '15000');
export const MAX_IMAGES_PER_LESSON = parseInt(process.env.MAX_IMAGES_PER_LESSON || '4');

Configuration:

IMAGE_GENERATION_TIMEOUT=15000    # 15 seconds per image
MAX_IMAGES_PER_LESSON=4           # Limit images per lesson

Provider Comparison

Feature	OpenRouter	Perplexity	Bittensor
Status	✅ Production	✅ Production	⚠️ Experimental
Setup Complexity	Low	Low	High
Cost	Pay-per-use	Pay-per-use	Variable
Response Time	Fast (1-3s)	Fast (1-2s)	Variable (3-10s)
Model Selection	100+ models	Proprietary	Subnet miners
Reliability	High	High	Moderate
Use Case	Primary LLM	Knowledge enrichment	Decentralized alternative

Recommended Configuration

Production Setup

# Primary AI provider
LLM_PROVIDER=openrouter
OPENROUTER_API_KEY="sk-or-v1-..."
OPENROUTER_SVG_MODEL=google/gemini-3.1-pro-preview

# Knowledge enrichment
PERPLEXITY_API_KEY="pplx-..."

# Image generation
IMAGE_PROVIDER=svg-llm
ENABLE_SVG_LLM=1
MAX_IMAGES_PER_LESSON=4
IMAGE_GENERATION_TIMEOUT=15000

# Fallback chains
SVG_MODEL_FALLBACKS="google/gemini-3.1-flash-lite-preview,google/gemini-3-flash-preview"

# Feature flags
USE_AI=1
ENABLE_STATS=1

Development Setup

# Minimal AI for testing
LLM_PROVIDER=openrouter
OPENROUTER_API_KEY="sk-or-v1-..."

# Disable expensive features
ENABLE_OPENROUTER_IMAGES=0
MAX_IMAGES_PER_LESSON=1

# Fast models
OPENROUTER_SVG_MODEL=google/gemini-3.1-flash-lite-preview

Troubleshooting

401 Unauthorized (OpenRouter)

Cause: Invalid API key or expired credits.Fix:

# Verify key
curl https://openrouter.ai/api/v1/auth/key \
  -H "Authorization: Bearer $OPENROUTER_API_KEY"

# Check credits
# Visit https://openrouter.ai/credits

402 Insufficient Credits

Cause: OpenRouter account balance is zero.Fix:

Add credits at openrouter.ai/credits
Fallback model will be tried automatically

404 Model Not Found

Cause: Model name typo or model no longer available.Fix:

# Use known-good model
OPENROUTER_SVG_MODEL=google/gemini-3.1-pro-preview

# Check available models
curl https://openrouter.ai/api/v1/models

Bittensor Connection Timeout

Cause: Subnet unreachable or wallet misconfigured.Fix:

# Test connection
curl https://archive.opentensor.ai/graphql \
  -H "Content-Type: application/json" \
  -d '{"query": "{__typename}"}'

# Enable fallback
BITTENSOR_FALLBACK_ENABLED=1

Next Steps

Security

Secure your AI provider API keys

Monitoring

Monitor AI usage and costs

Troubleshooting

Debug AI provider issues

​Overview

​Provider Selection

​OpenRouter (Primary)

​Setup

​Models Used

​Model Customization

​Fallback Chains

​Rate Limits & Costs

​Perplexity (Knowledge Enrichment)

​Setup

​Use Cases

​Bittensor Subnet 1 (Experimental)

​What is Bittensor?

​Setup

​Enable as Primary Provider

​Automatic Fallback

​Feature Flags

​Global AI Toggle

​Image Generation Controls

​Image Provider Selection

​Image Generation Timeouts

​Provider Comparison

​Recommended Configuration

​Production Setup

​Development Setup

​Troubleshooting

​Next Steps

Security

Monitoring

Troubleshooting

Overview

Provider Selection

OpenRouter (Primary)

Setup

Models Used

Model Customization

Fallback Chains

Rate Limits & Costs

Perplexity (Knowledge Enrichment)

Setup

Use Cases

Bittensor Subnet 1 (Experimental)

What is Bittensor?

Setup

Enable as Primary Provider

Automatic Fallback

Feature Flags

Global AI Toggle

Image Generation Controls

Image Provider Selection

Image Generation Timeouts

Provider Comparison

Recommended Configuration

Production Setup

Development Setup

Troubleshooting

Next Steps