Add a Custom Data Source

# src/strategy/sources/my_oracle.py
from typing import Any, Callable
from aether_forge.data_layer import DataSource, DataResult, DataSourceCost
 
class MyOracleSource(DataSource):
    name = "my-oracle"
 
    def __init__(self, api_key: str, base_url: str = "https://my-oracle.example.com"):
        self.api_key = api_key
        self.base_url = base_url
        self._calls = 0
        self._errors = 0
 
    def supports(self, capability: str) -> bool:
        return capability in {
            "my-oracle-price",
            "my-oracle-depth",
            "my-oracle-volume",
        }
 
    def fetch(self, capability: str, **params: Any) -> DataResult:
        import json
        from urllib import request
        token = params.get("token", "ETH")
        url = f"{self.base_url}/{capability}?token={token}"
        req = request.Request(url, headers={"X-API-Key": self.api_key})
        try:
            self._calls += 1
            with request.urlopen(req, timeout=10) as resp:
                data = json.loads(resp.read())
        except Exception as error:
            self._errors += 1
            raise RuntimeError(f"my-oracle fetch failed: {error}") from error
        return DataResult(
            source=self.name,
            capability=capability,
            data=data,
            cost=DataSourceCost(amount_usd=0.0, paid=False, payment_method="subscription"),
        )
 
    def status(self) -> dict[str, Any]:
        return {
            "name": self.name,
            "calls": self._calls,
            "errors": self._errors,
        }

from aether_forge.data_layer import DataRouter
from .sources.my_oracle import MyOracleSource
 
def build_router(config) -> DataRouter:
    sources = [
        MyOracleSource(api_key=config.get("my_oracle_key")),
        # ... other sources
    ]
    return DataRouter(sources=sources, fallback_chain=True)

{
  "data_sources": [
    {
      "name": "my-oracle",
      "type": "custom",
      "module": "src.strategy.sources.my_oracle:MyOracleSource",
      "config": {
        "api_key_env": "MY_ORACLE_KEY",
        "base_url": "https://my-oracle.example.com"
      },
      "priority": 1
    }
  ]
}

{
  "capabilities": [
    {
      "id": "my-oracle-price",
      "name": "Get oracle price",
      "kind": "read",
      "riskLevel": "low",
      "effectSemantics": "none",
      "credentialHandle": "my-oracle"
    }
  ],
  "credentials": [
    {
      "handle": "my-oracle",
      "provider": "my-oracle",
      "scope": "read-only"
    }
  ]
}

def test_my_oracle_source(monkeypatch):
    from src.strategy.sources.my_oracle import MyOracleSource
    source = MyOracleSource(api_key="test-key")
    # mock urlopen ...
    result = source.fetch("my-oracle-price", token="ETH")
    assert result.source == "my-oracle"
    assert result.data is not None