Initial Arka plugin registry: Official plugins mirror + Arka-signed index

11 plugins from github.com/librefang/librefang-registry plugins/.
index.json / index.json.sig are signed with Arka's Ed25519 key
(not upstream stats.librefang.ai). Private key is not in this repo.

plugins/mempalace-indexer/hooks/ingest.py

@@ -0,0 +1,129 @@
+#!/usr/bin/env python3
+"""MemPalace ingest hook for LibreFang.
+
+Searches MemPalace for memories relevant to the incoming user message
+and injects them into the agent's context as MemoryFragments.
+
+Input (stdin):  {"type": "ingest", "agent_id": "...", "message": "user text"}
+Output (stdout): {"memories": [{"content": "..."}]}
+
+Install: librefang plugin install mempalace-indexer && librefang plugin requirements mempalace-indexer
+"""
+import sys
+import json
+import os
+
+# ---------------------------------------------------------------------------
+# Configuration: read from LIBREFANG_PLUGIN_CONFIG (written by the runtime),
+# fall back to individual environment variables for direct invocation.
+# ---------------------------------------------------------------------------
+
+def _load_config():
+    cfg_path = os.environ.get("LIBREFANG_PLUGIN_CONFIG")
+    if cfg_path:
+        try:
+            with open(cfg_path) as f:
+                return json.load(f)
+        except (OSError, json.JSONDecodeError):
+            pass
+    return {}
+
+_cfg = _load_config()
+
+
+def _cfg_str(key, env_key, default):
+    if key in _cfg:
+        return str(_cfg[key])
+    return os.environ.get(env_key, default)
+
+
+def _cfg_int(key, env_key, default):
+    if key in _cfg:
+        try:
+            return int(_cfg[key])
+        except (TypeError, ValueError):
+            pass
+    return int(os.environ.get(env_key, default))
+
+
+def _cfg_float(key, env_key, default):
+    if key in _cfg:
+        try:
+            return float(_cfg[key])
+        except (TypeError, ValueError):
+            pass
+    return float(os.environ.get(env_key, default))
+
+
+PALACE_PATH = _cfg_str("palace_path", "MEMPALACE_PALACE_PATH",
+                        os.path.expanduser("~/.mempalace/palace"))
+MAX_MEMORY_CHARS = _cfg_int("max_chars", "MEMPALACE_MAX_CHARS", "300")
+
+# MemPalace returns similarity in [0, 1] — higher means more relevant.
+# Results below MIN_SIMILARITY are too dissimilar to be useful.
+# Set to 0 (or MEMPALACE_MIN_SIMILARITY=0) to disable filtering.
+MIN_SIMILARITY = _cfg_float("min_similarity", "MEMPALACE_MIN_SIMILARITY", "0.3")
+N_RESULTS = _cfg_int("n_results", "MEMPALACE_N_RESULTS", "5")
+
+
+def emit(obj):
+    """Write JSON response to stdout with trailing newline."""
+    json.dump(obj, sys.stdout)
+    sys.stdout.write("\n")
+
+
+def truncate_at_word(text, max_len):
+    """Truncate text at nearest word boundary."""
+    if len(text) <= max_len:
+        return text
+    truncated = text[:max_len]
+    last_space = truncated.rfind(" ")
+    if last_space > max_len // 2:
+        return truncated[:last_space] + "..."
+    return truncated + "..."
+
+
+def main():
+    try:
+        data = json.load(sys.stdin)
+    except (json.JSONDecodeError, EOFError):
+        emit({"memories": []})
+        return
+
+    message = data.get("message", "")
+    if not message or len(message) < 5:
+        emit({"memories": []})
+        return
+
+    try:
+        from mempalace.searcher import search_memories
+
+        results = search_memories(message, PALACE_PATH, n_results=N_RESULTS)
+
+        memories = []
+        for r in results.get("results", []):
+            text = r.get("text", "")
+            wing = r.get("wing", "") or "memory"
+            room = r.get("room", "")
+            similarity = r.get("similarity")
+
+            if not text:
+                continue
+
+            # Filter out low-relevance results when the backend provides a score.
+            # similarity=None means the backend didn't return one — allow through.
+            if similarity is not None and MIN_SIMILARITY > 0 and similarity < MIN_SIMILARITY:
+                continue
+
+            snippet = truncate_at_word(text, MAX_MEMORY_CHARS)
+            # Use wing/room (semantically meaningful) instead of raw source filename.
+            label = f"{wing}/{room}" if room else wing
+            memories.append({"content": f"[{label}] {snippet}"})
+
+        emit({"memories": memories})
+    except Exception as e:
+        emit({"memories": [], "error": str(e)})
+
+
+if __name__ == "__main__":
+    main()