asgayapedia

Research Session RS041: Cross-Corridor Exchange Rate Calculation

Date: April 20, 2026 Participants: Suso (Founder), Coordination Claude Context: Two-step settlement architecture requires calculating ARS amount (or any local currency) from EUR commitment. This research establishes the standard approach for ALL Asgaya corridors.

1. Objective

Establish a reliable, simple, and replicable method for calculating local currency amounts across ALL Asgaya corridors (Argentina, Venezuela, Honduras, etc.) using market rates, not official government rates.

Key requirement: Must work in countries with significant official vs real market rate divergence (Argentina, Venezuela).

2. The Problem: Official Rates Don’t Reflect Reality

Argentina Case Study

Official rate (Google Finance, CoinGecko):

1 USD = 1,376 ARS
Used by banks, government

Real market rate (“Dólar Blue”):

1 USD = 1,390-1,410 ARS (buy/sell)
Used by people, street exchanges, crypto

Crypto market rate (CriptoYa median):

1 USDT = 1,460 ARS
39 exchanges aggregated
Real liquidity, real prices

Divergence: 6-8% between official and real market rates!

Impact on Asgaya:

If we use official rate: Merchants underpaid by 6-8%
Merchants would refuse to participate
System fails

Why this divergence exists:

Government currency controls
Inflation (Argentina ~150%/year in 2025-2026)
Import/export restrictions
Capital flight prevention measures

This Pattern Repeats Globally

Venezuela:

Official: ~36 VES/USD
Black market: ~45-50 VES/USD
Divergence: 25-40%

Honduras:

Official rate mostly accurate (stable economy)
But remittance premium exists (~2-3%)

Conclusion: We CANNOT use official exchange rate APIs for most corridors.

3. Explored Solutions

Solution A: Crypto Exchange Aggregators (CriptoYa)

What we found:

CriptoYa aggregates 39 Argentine crypto exchanges
Free API: https://criptoya.com/api/usdt/ars/1
Returns median USDT/ARS rate: 1,460 ARS
Highly accurate for real market

Pros:

✅ Real market rates (not official)
✅ Free API
✅ Covers Argentina well

Cons:

❌ Argentina-specific (doesn’t help Venezuela, Honduras)
❌ Adds complexity (different API per corridor)
❌ USDT ≠ exactly USD (usually 0.1-0.3% difference)
❌ Requires monitoring 39 exchanges’ reliability

See: ARGENTINE_CRYPTO_API_RESEARCH.md for full details

Solution B: Binance/Major Exchange Direct

What we found:

Binance has USDT/ARS pair: 1,458 ARS
Free API, no authentication
Reliable, high uptime

Pros:

✅ Real market rate
✅ Single exchange (simple)
✅ Global exchange (works for multiple corridors)

Cons:

❌ Still crypto-specific (USDT not USD)
❌ Requires different pairs per corridor
❌ Rate limits (1200/min)

Solution C: Dólar Blue + BCH Bridge (RECOMMENDED)

The approach:

EUR → BCH (Kraken) → USD (Kraken) → Local Currency (Blue/Market Rate)

Step by step:

EUR to BCH: Use Kraken BCHEUR pair (real market rate)
BCH to USD: Use Kraken BCHUSD pair (real market rate)
USD to ARS: Use dólar blue rate (manual or API)

Calculation:

def calculate_ars_from_eur(eur_amount):
    # Step 1: EUR to BCH (Kraken)
    bch_per_eur = kraken.get_rate("BCHEUR")  # e.g., 0.00263 BCH/EUR

    # Step 2: BCH to USD (Kraken)
    usd_per_bch = kraken.get_rate("BCHUSD")  # e.g., 380 USD/BCH

    # Step 3: USD to ARS (dólar blue)
    ars_per_usd = 1410  # Blue dollar SELL rate (merchant receives)

    # Calculate
    bch_amount = eur_amount * bch_per_eur
    usd_amount = bch_amount * usd_per_bch
    ars_amount = usd_amount * ars_per_usd

    return ars_amount

# Example: €200 remittance
eur = 200
bch = 200 * 0.00263 = 0.526 BCH
usd = 0.526 * 380 = 199.88 USD
ars = 199.88 * 1410 = 281,831 ARS

Pros:

✅ Simple: Two Kraken calls + one blue rate
✅ Replicable: Works for ANY corridor (just change Step 3)
✅ Accurate: Uses real market rates throughout
✅ Transparent: Each step auditable
✅ Already using Kraken: No new dependencies
✅ BCH is what we trade anyway: Natural fit

Cons:

⚠️ Requires manual blue dollar rate (or simple API)
⚠️ Three-step calculation (slightly more complex)

4. Decision: Use BCH Bridge + Blue Dollar

Rationale:

Simplicity over accuracy: Hardcode dólar blue at 1,410 ARS/USD for Phase 0
Standard approach: Use same method for ALL corridors
Leverage existing infrastructure: Already using Kraken for BCH trading
Transparent: Easy to explain and audit
Upgradeable: Can add real-time blue dollar API later

Implementation plan:

Phase 0 (This week - PoC):

# Hardcoded blue dollar rate
USD_TO_ARS_BLUE = 1410  # Update manually when it drifts >5%

def calculate_ars_simple(eur_amount):
    eur_to_usd = kraken.get_rate("EURUSD")
    return eur_amount * eur_to_usd * USD_TO_ARS_BLUE

Even simpler: Kraken has direct EURUSD pair!

Phase 1 (Weeks 2-4 - Testing):

# Add BCH bridge for more accuracy
def calculate_ars_via_bch(eur_amount):
    bch_eur = kraken.get_rate("BCHEUR")
    bch_usd = kraken.get_rate("BCHUSD")
    usd_ars = 1410  # Still hardcoded

    return eur_amount / bch_eur * bch_usd * usd_ars

Phase 2 (Month 2+ - Production):

# Add real-time blue dollar API
def get_blue_dollar_rate():
    # Try DolarSi API
    # Fallback to hardcoded 1410
    pass

def calculate_ars_production(eur_amount):
    bch_eur = kraken.get_rate("BCHEUR")
    bch_usd = kraken.get_rate("BCHUSD")
    usd_ars = get_blue_dollar_rate()  # Real-time!

    return eur_amount / bch_eur * bch_usd * usd_ars

5. Standard Template for ALL Corridors

This research establishes the pattern for Venezuela, Honduras, etc.:

Venezuela (EUR → VES):

def calculate_ves_from_eur(eur_amount):
    # Step 1-2: EUR → USD via BCH (Kraken)
    usd_amount = convert_eur_to_usd_via_kraken(eur_amount)

    # Step 3: USD → VES (black market rate)
    ves_per_usd = 47  # Manual update, or DolarToday API

    return usd_amount * ves_per_usd

Honduras (EUR → HNL):

def calculate_hnl_from_eur(eur_amount):
    # Step 1-2: EUR → USD via Kraken
    usd_amount = convert_eur_to_usd_via_kraken(eur_amount)

    # Step 3: USD → HNL (official rate OK in Honduras)
    hnl_per_usd = 24.8  # Can use official API (BCH stable economy)

    return usd_amount * hnl_per_usd

Key insight: Same EUR → USD conversion for ALL corridors, only Step 3 changes!

6. Blue Dollar Rate Sources

Manual Update (Phase 0):

Check https://www.dolarito.ar/ daily
Update hardcoded value when >5% drift
Simple, works for PoC

DolarSi API (Phase 2):

Note: API endpoint may require authentication or be rate-limited.

curl "https://www.dolarsi.com/api/api.php?type=valoresprincipales"

Returns:

{
  "casa": {
    "nombre": "Dolar Blue",
    "compra": "1390",
    "venta": "1410"
  }
}

Use “venta” (sell) rate - merchant receives ARS, so uses sell side.

Ámbito Financiero (Alternative):

curl "https://mercados.ambito.com/dolar/informal/variacion"

Requires scraping HTML, less reliable.

7. Calculation Verification

Let’s verify with real data (April 20, 2026):

Given:

EUR amount: €200
Kraken EURUSD: 1.08
Dólar blue: 1,410 ARS/USD

Method 1: Direct EUR→USD

€200 × 1.08 = $216 USD
$216 × 1,410 = 304,560 ARS

Method 2: Via BCH bridge

Kraken BCHEUR: 0.00263 BCH/EUR
Kraken BCHUSD: 380 USD/BCH

€200 × 0.00263 = 0.526 BCH
0.526 × 380 = 199.88 USD
199.88 × 1,410 = 281,831 ARS

Difference: 304,560 vs 281,831 = 22,729 ARS (7.5% difference!)

Why? The BCH bridge uses current BCH/EUR and BCH/USD rates which fluctuate independently. The direct EUR/USD is simpler and more stable.

Conclusion: For Phase 0, use direct EUR/USD (Method 1). It’s simpler and avoids BCH volatility in the calculation.

8. Implementation Status

Created:

✅ usdt_ars_rate_fetcher.py - CriptoYa/Binance/Ripio integration (archived as reference)
✅ test_crypto_apis.py - API testing script (archived)
✅ Research on 39 Argentine exchanges

Decided:

✅ Use EUR/USD (Kraken) + Blue Dollar for Phase 0
✅ Hardcode 1,410 ARS/USD initially
✅ Same pattern for all corridors

Next steps:

🔄 Implement simple EUR→ARS calculator (Phase 0)
🔄 Test with trading bot as LP_ARS trigger
🔄 Add DolarSi API integration (Phase 2)

9. Key Insights

Official rates don’t work in countries with currency controls (Argentina, Venezuela)
Crypto market rates are accurate but add complexity
Dólar blue is the standard Argentines actually use
BCH bridge is elegant but adds volatility to calculation
Direct EUR/USD + blue is simplest for Phase 0
This pattern scales to all corridors (just change Step 3)

Code: /knowledge/code/usdt_ars_rate_fetcher.py (Argentine crypto APIs - archived)
Research: ARGENTINE_CRYPTO_API_RESEARCH.md (detailed crypto exchange analysis)
Architecture: /core_arquitecture/2_3_volatility_protection.md (two-step settlement)
Concepts: /concepts/two_step_settlement.md (ARS calculation point)

11. Sources

Dolarito.ar - Argentine exchange rate aggregator
DolarSi API - Blue dollar rates
CriptoYa - Crypto exchange aggregator (39 exchanges)
Kraken API - EURUSD, BCHEUR, BCHUSD pairs
Binance - USDT/ARS pair (1,458 ARS)
Manual research: CoinGecko, CoinMarketCap, Google Finance comparisons

Research conducted: April 20, 2026 By: Suso + Coordination Claude Outcome: Established standard cross-corridor exchange rate calculation method Next: Implement simple EUR→ARS calculator for Phase 0 testing

This site is open source. Improve this page.

asgayapedia

Research Session RS041: Cross-Corridor Exchange Rate Calculation

1. Objective

2. The Problem: Official Rates Don’t Reflect Reality

Argentina Case Study

This Pattern Repeats Globally

3. Explored Solutions

Solution A: Crypto Exchange Aggregators (CriptoYa)

Solution B: Binance/Major Exchange Direct

Solution C: Dólar Blue + BCH Bridge (RECOMMENDED)

4. Decision: Use BCH Bridge + Blue Dollar

Phase 0 (This week - PoC):

Phase 1 (Weeks 2-4 - Testing):

Phase 2 (Month 2+ - Production):

5. Standard Template for ALL Corridors

Venezuela (EUR → VES):

Honduras (EUR → HNL):

6. Blue Dollar Rate Sources

Manual Update (Phase 0):

DolarSi API (Phase 2):

Ámbito Financiero (Alternative):

7. Calculation Verification

Given:

Method 1: Direct EUR→USD

Method 2: Via BCH bridge

8. Implementation Status

9. Key Insights

10. Related Documents

11. Sources