merge: chore/cleanup-remove-bloat-and-secrets into main

app/routers/databus_gateway.py

@@ -0,0 +1,76 @@
+#!/usr/bin/env python3
+"""#10 — DataBus Public API Gateway Router. Free tier + x402 paid tier."""
+
+from fastapi import APIRouter, Header, HTTPException
+from pydantic import BaseModel
+
+from app.databus_gateway import (
+    SUPPORTED_CHAINS,
+    TIER_LIMITS,
+    _check_rate,
+    databus_cross_chain,
+    databus_get,
+    verify_x402_payment,
+)
+
+router = APIRouter(prefix="/api/v1/databus", tags=["databus-gateway"])
+
+
+class ChainQuery(BaseModel):
+    chain: str
+    endpoint: str = "overview"
+    params: dict | None = None
+
+
+class CrossChainQuery(BaseModel):
+    query: str
+    chains: list[str] | None = None
+
+
+@router.get("/chains")
+async def list_chains():
+    """List all supported chains with tier availability."""
+    return {"chains": SUPPORTED_CHAINS, "total": len(SUPPORTED_CHAINS)}
+
+
+@router.get("/{chain}/{endpoint:path}")
+async def query_chain(chain: str, endpoint: str, x_rmi_key: str = Header(None), x_x402_sig: str = Header(None)):
+    """Query a single DataBus chain. Free tier with rate limiting, paid tier via x402 header."""
+    tier = "free"
+    if x_x402_sig:
+        valid = await verify_x402_payment(x_x402_sig, f"{chain}/{endpoint}")
+        if valid:
+            tier = "pro"
+        else:
+            raise HTTPException(402, "Invalid x402 payment signature")
+
+    limits = TIER_LIMITS[tier]
+    client_id = x_rmi_key or "anonymous"
+    rate_key = f"databus:{client_id}:{tier}"
+
+    if not _check_rate(rate_key, limits["requests_per_hour"]):
+        raise HTTPException(429, f"Rate limit exceeded ({limits['requests_per_hour']}/hr for {tier} tier)")
+
+    if chain not in SUPPORTED_CHAINS:
+        raise HTTPException(404, f"Chain '{chain}' not supported. Use /api/v1/databus/chains for full list.")
+
+    result = await databus_get(chain, endpoint, tier=tier)
+    return {
+        "chain": result.chain,
+        "data": result.data,
+        "source": result.source,
+        "cached": result.cached,
+        "latency_ms": result.latency_ms,
+        "tier": tier,
+    }
+
+
+@router.post("/cross-chain")
+async def cross_chain_query(query: CrossChainQuery):
+    """Query multiple DataBus chains in parallel."""
+    results = await databus_cross_chain(query.query, query.chains)
+    return {
+        "query": query.query,
+        "chains_queried": list(results.keys()),
+        "results": {c: {"data": r.data, "cached": r.cached} for c, r in results.items()},
+    }