asgayapedia

RS036: Kraken Ticker API for BCH/EUR Price Feed

Date: April 15, 2026
Duration: 30 minutes
Status: Complete — Ready for SW23 implementation
Next: Integrate ticker endpoint into kraken_query.py

Objective

Document how to get current BCH/EUR price from Kraken’s public API for use in the escrow price feed. This fills a knowledge gap from RS017-019 which covered Balance/Trade/Withdraw but not price queries.

Endpoint Details

Public Ticker Endpoint

URL: https://api.kraken.com/0/public/Ticker
Method: GET
Authentication: None required (public endpoint)
Rate Limit: Not documented for public endpoints (assumed permissive)

Parameters:

pair (required): Currency pair, e.g., BCHEUR

Example request:

curl "https://api.kraken.com/0/public/Ticker?pair=BCHEUR"

Response Format

Successful response:

{
  "error": [],
  "result": {
    "BCHEUR": {
      "a": ["373.810000", "1", "1.000"],
      "b": ["373.570000", "1", "1.000"],
      "c": ["373.540000", "0.30129519"],
      "v": ["289.14403311", "313.55040886"],
      "p": ["368.297120", "368.450088"],
      "t": [420, 454],
      "l": ["363.100000", "363.100000"],
      "h": ["374.840000", "374.840000"],
      "o": "370.860000"
    }
  }
}

Field Definitions

Field	Meaning	Format	Use Case
`a`	Ask price (sell offers)	[price, whole lot volume, lot volume]	Use this for buying BCH
`b`	Bid price (buy offers)	[price, whole lot volume, lot volume]	Use for selling BCH
`c`	Last trade closed	[price, lot volume]	Reference/display only
`v`	Volume	[today, last 24 hours]	Market activity indicator
`p`	Volume weighted average	[today, last 24 hours]	Average price
`t`	Number of trades	[today, last 24 hours]	Market activity
`l`	Low price	[today, last 24 hours]	Price range
`h`	High price	[today, last 24 hours]	Price range
`o`	Opening price	today	Daily reference

Critical: All price arrays have price as first element: field[0]

Which Price to Use

For Escrow Buying BCH (Our Use Case)

Use: result["BCHEUR"]["a"][0] (ask price)

Reasoning:

Ask price = what you PAY to buy BCH
This is what market buy order will execute at
Most accurate for “how much EUR for X BCH”

Example from live data:

Ask: €373.81 (we pay this)
Bid: €373.57 (we’d get this selling)
Last: €373.54 (historical, not current)

For buying: Always use ask (higher price, what we pay)

Conversion Formula

EUR → BCH amount:

ask_price = float(data["result"]["BCHEUR"]["a"][0])
bch_amount = eur_amount / ask_price

Example:

€100 / €373.81 = 0.2675 BCH

Error Handling

Error response format:

{
  "error": ["EQuery:Unknown asset pair"],
  "result": {}
}

Common errors:

EQuery:Unknown asset pair - Invalid pair name (try XBCHZEUR if BCHEUR fails)
Empty response - Network/API issues
Missing fields - API change (unlikely for ticker)

Recommended handling:

Check error array is empty
Verify result contains pair key
Validate price is numeric and > 0
Implement retry logic for network failures
Have fallback price source

Rate Limiting

Not explicitly documented for public ticker endpoint

Conservative approach:

Query at most once per minute for price updates
Cache price for 30-60 seconds
Don’t query per-transaction (use cached value)

For SMS bridge:

Query when SMS arrives, cache for that transaction
Don’t hammer API with repeated calls

Implementation Example

import requests

def get_bch_eur_price():
    """
    Get current BCH/EUR ask price from Kraken public API.
    Returns price in EUR or None if error.
    """
    try:
        response = requests.get(
            "https://api.kraken.com/0/public/Ticker",
            params={"pair": "BCHEUR"},
            timeout=10
        )
        data = response.json()
        
        # Check for API errors
        if data.get("error"):
            print(f"Kraken API error: {data['error']}")
            return None
        
        # Extract ask price (what we pay to buy)
        ask_price = float(data["result"]["BCHEUR"]["a"][0])
        
        return ask_price
        
    except (requests.RequestException, KeyError, ValueError) as e:
        print(f"Error getting Kraken price: {e}")
        return None

# Usage:
price = get_bch_eur_price()
if price:
    print(f"Current BCH/EUR ask price: €{price:.2f}")
    eur_amount = 100
    bch_amount = eur_amount / price
    print(f"€{eur_amount} = {bch_amount:.8f} BCH")

Expected output (based on live data):

Current BCH/EUR ask price: €373.81
€100 = 0.26752430 BCH

Comparison with External Feed

Current system uses: get_eur_to_bch() from get_price.py (external service)

Kraken ticker advantages:

Direct from exchange (no middleman)
Same source we’ll use for buying BCH
Matches actual execution price
No external dependency risk

Considerations:

Kraken downtime affects both price and trading
Should still have fallback for resilience
Rate limits unknown (use conservatively)

Integration Points

Immediate (SW23):

Add get_bch_eur_price() to kraken_query.py
Replace get_eur_to_bch() call in smsbridge_loop.py
Keep external feed as fallback

Future (when buying enabled):

Price query and buy order use same exchange (consistency)
Can verify buy execution against ticker price
Single API integration point

Testing Notes

Live test performed: 2026-04-15

Endpoint: Working ✅
Pair name: BCHEUR (not XBCHZEUR) ✅
Response format: As documented ✅
Ask price: €373.81
Bid price: €373.57
Spread: €0.24 (0.064%)

Small spread = liquid market = good for PoC

Knowledge Gap Filled

RS017-019 covered:

✅ Balance endpoint (private)
✅ Buy orders (private, trading)
✅ Withdrawals (private, with whitelisting)

RS036 adds:

✅ Price ticker (public, no auth)
✅ Which price to use (ask for buying)
✅ Response parsing
✅ Error handling

Complete Kraken knowledge base now ready for SW23 implementation.

Next Steps

SW23: Integrate ticker into kraken_query.py
Test: Verify price updates work in smsbridge flow
Compare: Kraken vs. external feed accuracy
Document: Any integration learnings

Research completed: April 15, 2026
Prepared by: Suso (testing), Coordination (documentation)
Ready for: SW23 implementation

This research session completes the Kraken API knowledge base started in RS017-019.

---

## Order Book Depth (For Production Buying)

### Why Depth Matters

The Ticker endpoint only shows the **best ask price and volume at that level**. For larger purchases, you may need to buy across multiple price levels.

**Example:**
- Want: €1000 worth of BCH
- Level 1: €373.81 with 1 BCH available (€373.81)
- Level 2: €373.85 with 2.5 BCH available (€934.62)
- Must buy from both levels → Average price €373.83

### Depth Endpoint

**URL:** `https://api.kraken.com/0/public/Depth`  
**Parameters:**
- `pair=BCHEUR`
- `count=10` (number of price levels, default 100)

**Request:**
```bash
curl "https://api.kraken.com/0/public/Depth?pair=BCHEUR&count=10"

Response format:

{
  "result": {
    "BCHEUR": {
      "asks": [
        ["373.810000", "1.000", 1234567890],
        ["373.850000", "2.500", 1234567891],
        ...
      ],
      "bids": [...]
    }
  }
}

Each ask: [price, volume, timestamp]

Multi-Level Buying Strategy

For PoC: Use simple market order (Kraken handles multi-level automatically)

For Production:

Query depth before buying
Calculate expected execution across levels
Place market order
Compare actual execution vs. expected
Log average price and levels used
Alert if slippage > threshold

See: Future SW document for production buying implementation

Liquidity Analysis (Live Data 2026-04-15)

Order book depth test:

Top 5 ask levels:

€373.78: 0.051 BCH
€373.79: 0.342 BCH
€373.80: 1.806 BCH
€373.83: 0.051 BCH
€373.84: 1.590 BCH

Total available: 3.84 BCH (€1,435)

Market impact simulation:

Order Size	BCH Received	Avg Price	Slippage	Impact
€50	0.134 BCH	€373.79	€0.01	Negligible
€200	0.535 BCH	€373.79	€0.02	0.005% - Tiny
€500	1.337 BCH	€373.79	€0.02	0.005% - Tiny
€1,000	2.675 BCH	€373.80	€0.05	0.013% - Minimal

Conclusion: BCHEUR pair has sufficient liquidity for Asgaya’s use case. Even €1,000 transactions cause <0.02% slippage. No need for order splitting or advanced strategies for PoC/early production.

PoC transactions (€1-100): Zero market impact
Production (€100-1,000): Minimal impact (<0.02%)
Future consideration: Orders >€5,000 might need splitting

Should I Save This as RS036?

Location: ~/Documents/asgaya/knowledge/research/RS036_kraken_ticker_api.md

Then tomorrow’s SW23 can reference it: “See RS036 for endpoint details”

Knowledge gap filled! ✅

Want me to save this, or do you want to review/edit first? 📝

This site is open source. Improve this page.