feat(inference): real local Ollama backend for the InferenceGateway adapter

Makefile

@@ -40,6 +40,9 @@ validate-consent-before-staging:
 validate-inference-gateway:
 	$(PYTHON) scripts/validate-inference-gateway.py
 
+validate-inference-backends:
+	$(PYTHON) scripts/validate-inference-backends.py
+
 validate-inference-receipt:
 	$(PYTHON) scripts/validate-inference-receipt.py
 

scripts/validate-inference-backends.py

@@ -0,0 +1,60 @@
+#!/usr/bin/env python3
+"""Validate the Ollama serving backend: admitted → real output; failure → audited denial.
+
+Uses an injected transport so no live daemon is required. The property asserted is that
+a backend failure (daemon down, malformed response) never becomes a silent success — the
+gateway turns it into a denied audit with no output. One positive case confirms a served
+call returns the model output with usage.
+"""
+from __future__ import annotations
+import sys
+from pathlib import Path
+
+SRC = Path(__file__).resolve().parents[1] / "src"
+if str(SRC) not in sys.path:
+    sys.path.insert(0, str(SRC))
+
+from agent_machine.inference_gateway import serve  # noqa: E402
+from agent_machine.inference_backends import ollama_backend  # noqa: E402
+
+ACTIVE = {"id": "local-ollama", "kind": "InferenceProvider", "status": "active"}
+REQ = {"model": "llama3.3", "caller": "human:michael", "purpose": "discover",
+       "space": "user-space", "input": "say hi",
+       "consent": {"policyDecisionRef": "urn:srcos:policy-decision:abc"}}
+
+failures = []
+def check(name, cond):
+    print(("  ok   " if cond else "  FAIL ") + name)
+    if not cond: failures.append(name)
+
+# ── positive: injected transport returns a canned Ollama reply ──
+seen = {}
+def fake_ok(url, payload):
+    seen["url"] = url; seen["payload"] = payload
+    return {"response": "hi there", "prompt_eval_count": 3, "eval_count": 2}
+resp, audit = serve(REQ, provider=ACTIVE, backend=ollama_backend(transport=fake_ok))
+check("served call returns model output", resp and resp["output"] == "hi there")
+check("usage mapped from ollama counts", resp and resp["usage"] == {"prompt_tokens": 3, "completion_tokens": 2})
+check("audit outcome ok", audit["outcome"] == "ok")
+check("request hits /api/generate with model+prompt", seen.get("url","").endswith("/api/generate")
+      and seen["payload"]["model"] == "llama3.3" and "say hi" in seen["payload"]["prompt"])
+
+# ── negative: daemon unreachable → transport raises → audited denial, no output ──
+def down(url, payload): raise ConnectionError("daemon down")
+resp, audit = serve(REQ, provider=ACTIVE, backend=ollama_backend(transport=down))
+check("unreachable daemon → no output", resp is None)
+check("unreachable daemon → denied audit", audit["outcome"] == "denied")
+
+# ── negative: malformed response (no 'response' field) → audited denial ──
+def bad(url, payload): return {"unexpected": True}
+resp, audit = serve(REQ, provider=ACTIVE, backend=ollama_backend(transport=bad))
+check("malformed reply → no output", resp is None)
+check("malformed reply → denied audit", audit["outcome"] == "denied")
+
+# ── still fail-closed on missing consent, even with a working backend ──
+resp, audit = serve({**REQ, "consent": {}}, provider=ACTIVE, backend=ollama_backend(transport=fake_ok))
+check("no consent still refused with live backend", resp is None and audit["outcome"] == "denied")
+
+if failures:
+    print(f"\nFAILED: {len(failures)} check(s)"); sys.exit(1)
+print("\nOK: Ollama backend serves when admitted and is an audited denial on any failure")

src/agent_machine/inference_backends.py

@@ -0,0 +1,65 @@
+"""Serving backends for the local InferenceGateway adapter.
+
+A backend is the callable the gateway invokes once a call is admitted:
+`backend(request) -> {"output": str, "usage": dict}`. The Ollama backend runs a model
+on the local Ollama daemon — no egress, fully sovereign (privacy_profile sovereign-local).
+The HTTP transport is injectable so the backend is testable without a live daemon, and a
+failure (daemon down, bad response) raises — which the gateway turns into an audited
+denial, never a silent success.
+"""
+from __future__ import annotations
+
+import json
+import os
+import urllib.request
+from typing import Any, Callable, Dict, List, Optional
+
+DEFAULT_HOST = "http://127.0.0.1:11434"
+Transport = Callable[[str, Dict[str, Any]], Dict[str, Any]]
+
+
+def _urllib_transport(url: str, payload: Dict[str, Any]) -> Dict[str, Any]:
+    data = json.dumps(payload).encode("utf-8")
+    req = urllib.request.Request(url, data=data, headers={"Content-Type": "application/json"}, method="POST")
+    with urllib.request.urlopen(req, timeout=60) as resp:  # noqa: S310 (local daemon)
+        return json.loads(resp.read().decode("utf-8"))
+
+
+def _to_prompt(value: Any) -> str:
+    if isinstance(value, str):
+        return value
+    if isinstance(value, list):  # chat-style messages → flattened prompt
+        parts: List[str] = []
+        for m in value:
+            if isinstance(m, dict):
+                parts.append(f"{m.get('role', 'user')}: {m.get('content', '')}")
+            else:
+                parts.append(str(m))
+        return "\n".join(parts)
+    return str(value)
+
+
+def ollama_backend(*, model: Optional[str] = None, host: Optional[str] = None,
+                   transport: Optional[Transport] = None) -> Callable[[Dict[str, Any]], Dict[str, Any]]:
+    """Return a gateway backend that serves via the local Ollama daemon (no egress)."""
+    host = (host or os.environ.get("OLLAMA_HOST") or DEFAULT_HOST).rstrip("/")
+    xport = transport or _urllib_transport
+
+    def _call(request: Dict[str, Any]) -> Dict[str, Any]:
+        payload = {
+            "model": request.get("model") or model or "llama3.3",
+            "prompt": _to_prompt(request.get("input", "")),
+            "stream": False,
+        }
+        data = xport(f"{host}/api/generate", payload)
+        if not isinstance(data, dict) or "response" not in data:
+            raise ValueError("ollama: response missing 'response' field")
+        return {
+            "output": data["response"],
+            "usage": {
+                "prompt_tokens": data.get("prompt_eval_count", 0),
+                "completion_tokens": data.get("eval_count", 0),
+            },
+        }
+
+    return _call