v0.1.31 - Alternative Crypto API Support with Automatic Fallback

🌐 Alternative Crypto API Support with Automatic Fallback

This release adds alternative API support for crypto data synchronization, enabling servers blocked by CryptoCompare to fetch data from another aipriceaction instance.

🔧 Key Changes

Alternative Crypto Data Source

• New AiPriceActionClient for fetching from alternative API endpoints
• Automatic source selection via environment variables
• Seamless fallback to CryptoCompare if alternative API fails
• Host header support for CDN/proxy bypass

Efficient Data Fetching

• Single API call fetches all cryptos (efficient batch processing)
• Supports all intervals: 1D (daily), 1H (hourly), 1m (minute)
• Filters crypto-specific data from combined response

Configuration via Environment Variables

• CRYPTO_WORKER_TARGET_URL: Alternative API base URL
• CRYPTO_WORKER_TARGET_HOST: Optional Host header for CDN/proxy bypass

🚀 Use Cases

Scenario: Server Blocked by CryptoCompare

Server A (has CryptoCompare access):

./target/release/aipriceaction serve --port 3000

Server B (blocked by CryptoCompare):

export CRYPTO_WORKER_TARGET_URL="https://api-server-a.example.com"
export CRYPTO_WORKER_TARGET_HOST="api.aipriceaction.com"
./target/release/aipriceaction serve --port 3001

Server B worker now fetches crypto data from Server A's /tickers endpoint.

📊 Architecture

Data Flow:

1. Crypto worker checks environment variables on startup
2. If CRYPTO_WORKER_TARGET_URL is set → use alternative API
3. If not set → use CryptoCompare (default behavior)
4. On failure → automatic fallback to CryptoCompare

API Call Example:

GET https://api-server-a.example.com/tickers?mode=crypto&interval=1m&start_date=2025-11-19
Host: api.aipriceaction.com

Returns all crypto data in one response (108,646 records for 98 cryptos).

🐛 Bug Fixes

Fixed Host Header Handling

• Fixed "builder error" when setting Host header in reqwest
• Use HeaderValue::from_str() for proper header encoding
• Add graceful fallback if header value is invalid
• Improved error messages with detailed debugging info

🔍 Technical Details

New Components:

• src/services/crypto_api_client.rs: API proxy client (218 lines)
• CryptoDataSource enum: Abstracts data source (CryptoCompare vs ApiProxy)
• Automatic fallback logic in CryptoFetcher

Startup Logging:

INFO Starting crypto worker with two-tier sync strategy
INFO   - Data Source: Alternative API (https://api-server.example.com)
INFO   - Host Header: api.aipriceaction.com
INFO   - Fallback: CryptoCompare API (if alternative fails)

Fetch Logging:

DEBUG Setting Host header: api.aipriceaction.com
DEBUG Host header set successfully
DEBUG Sending request to: https://api-server.example.com/tickers?...
INFO Fetched 195 records for interval 1D from API

📝 Files Modified

• src/services/crypto_api_client.rs (NEW): API proxy client
• src/services/crypto_fetcher.rs: Dual-source support with fallback (+189 lines)
• src/services/mod.rs: Export new client
• src/worker/crypto_worker.rs: Startup logging for data source (+26 lines)
• CLAUDE.md: Documentation for environment variables (+28 lines)

⚙️ Configuration

Environment Variables:

# Alternative API URL (required to enable alternative source)
export CRYPTO_WORKER_TARGET_URL="https://api-server.example.com"

# Host header for CDN/proxy bypass (optional)
export CRYPTO_WORKER_TARGET_HOST="api.aipriceaction.com"

Important Notes:

• Worker-only feature: CLI commands (crypto-pull) always use CryptoCompare directly
• Automatic fallback ensures reliability
• Zero changes to CSV format or enhancement logic
• Drop-in replacement for blocked servers

🎯 Benefits

✅ Enables crypto sync on servers blocked by CryptoCompare
✅ Single API call for all cryptos (efficient)
✅ Automatic fallback ensures reliability
✅ Host header support for CDN/proxy scenarios
✅ Zero configuration changes to existing deployments
✅ Same CSV format and enhancement pipeline

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Full Changelog: v0.1.30...v0.1.31