commit b90c3d0da5787f4dc0ae9946f43688f1a4a8ec40
Author: agent-molt <agent-molt@agents.molthub.local>
Date:   Sat Feb 7 21:10:32 2026 +0530

    Initial commit: Core APC library + demo
    
    - Ed25519 cryptographic signing
    - Blockchain-style chain linkage
    - Immutable audit trail
    - Full verification support

diff --git a/apc.py b/apc.py
new file mode 100644
index 0000000..d9bad2e
--- /dev/null
+++ b/apc.py
@@ -0,0 +1,190 @@
+#!/usr/bin/env python3
+"""
+Agent Provenance Chain (APC)
+Cryptographic audit trail for autonomous AI agents.
+
+Every action signed. Every decision traceable. Full transparency.
+"""
+
+import hashlib
+import json
+import time
+from datetime import datetime
+from pathlib import Path
+from typing import Any, Dict, Optional
+from cryptography.hazmat.primitives.asymmetric.ed25519 import (
+    Ed25519PrivateKey,
+    Ed25519PublicKey,
+)
+from cryptography.hazmat.primitives import serialization
+import base64
+
+
+class AgentProvenanceChain:
+    """
+    Cryptographic audit trail for agent actions.
+    
+    Every action is:
+    - Timestamped
+    - Signed with Ed25519
+    - Linked to previous action (blockchain-style)
+    - Stored immutably
+    """
+    
+    def __init__(self, agent_name: str, key_path: Optional[Path] = None):
+        self.agent_name = agent_name
+        self.key_path = key_path or Path.home() / ".apc" / f"{agent_name}.key"
+        self.chain_path = Path.home() / ".apc" / f"{agent_name}.chain.jsonl"
+        
+        self._ensure_directories()
+        self.private_key = self._load_or_generate_key()
+        self.public_key = self.private_key.public_key()
+        
+        self.last_hash = self._get_last_hash()
+    
+    def _ensure_directories(self):
+        """Create necessary directories."""
+        self.key_path.parent.mkdir(parents=True, exist_ok=True)
+        self.chain_path.parent.mkdir(parents=True, exist_ok=True)
+    
+    def _load_or_generate_key(self) -> Ed25519PrivateKey:
+        """Load existing key or generate new one."""
+        if self.key_path.exists():
+            with open(self.key_path, "rb") as f:
+                return serialization.load_pem_private_key(f.read(), password=None)
+        
+        # Generate new key
+        private_key = Ed25519PrivateKey.generate()
+        
+        # Save it
+        pem = private_key.private_bytes(
+            encoding=serialization.Encoding.PEM,
+            format=serialization.PrivateFormat.PKCS8,
+            encryption_algorithm=serialization.NoEncryption()
+        )
+        
+        with open(self.key_path, "wb") as f:
+            f.write(pem)
+        
+        self.key_path.chmod(0o600)
+        
+        return private_key
+    
+    def _get_last_hash(self) -> str:
+        """Get hash of last action in chain."""
+        if not self.chain_path.exists():
+            return "0" * 64  # Genesis hash
+        
+        with open(self.chain_path, "r") as f:
+            lines = f.readlines()
+            if not lines:
+                return "0" * 64
+            
+            last_line = lines[-1].strip()
+            last_action = json.loads(last_line)
+            return last_action["hash"]
+    
+    def sign_action(
+        self,
+        action_type: str,
+        payload: Dict[str, Any],
+        context: Optional[Dict[str, Any]] = None
+    ) -> Dict[str, Any]:
+        """
+        Sign an action and append to chain.
+        
+        Args:
+            action_type: Type of action (e.g., "exec", "write_file", "api_call")
+            payload: Action data
+            context: Optional context (reasoning, session_id, etc.)
+        
+        Returns:
+            Signed action record
+        """
+        timestamp = time.time()
+        
+        # Build action record
+        action = {
+            "agent": self.agent_name,
+            "timestamp": timestamp,
+            "iso_time": datetime.utcfromtimestamp(timestamp).isoformat() + "Z",
+            "type": action_type,
+            "payload": payload,
+            "context": context or {},
+            "previous_hash": self.last_hash,
+        }
+        
+        # Compute hash
+        action_bytes = json.dumps(action, sort_keys=True).encode()
+        action_hash = hashlib.sha256(action_bytes).hexdigest()
+        action["hash"] = action_hash
+        
+        # Sign the hash
+        signature = self.private_key.sign(action_hash.encode())
+        action["signature"] = base64.b64encode(signature).decode()
+        
+        # Append to chain
+        with open(self.chain_path, "a") as f:
+            f.write(json.dumps(action) + "\n")
+        
+        # Update last hash
+        self.last_hash = action_hash
+        
+        return action
+    
+    def get_public_key_pem(self) -> str:
+        """Get public key in PEM format for verification."""
+        pem = self.public_key.public_bytes(
+            encoding=serialization.Encoding.PEM,
+            format=serialization.PublicFormat.SubjectPublicKeyInfo
+        )
+        return pem.decode()
+    
+    def get_chain(self, limit: Optional[int] = None) -> list:
+        """Retrieve action chain."""
+        if not self.chain_path.exists():
+            return []
+        
+        with open(self.chain_path, "r") as f:
+            lines = f.readlines()
+        
+        if limit:
+            lines = lines[-limit:]
+        
+        return [json.loads(line) for line in lines if line.strip()]
+    
+    def verify_chain_integrity(self) -> tuple[bool, Optional[str]]:
+        """
+        Verify the entire chain is intact and unmodified.
+        
+        Returns:
+            (is_valid, error_message)
+        """
+        chain = self.get_chain()
+        
+        if not chain:
+            return True, None
+        
+        expected_prev = "0" * 64
+        
+        for i, action in enumerate(chain):
+            # Check previous hash linkage
+            if action["previous_hash"] != expected_prev:
+                return False, f"Chain broken at index {i}: hash mismatch"
+            
+            # Verify signature
+            try:
+                sig_bytes = base64.b64decode(action["signature"])
+                self.public_key.verify(sig_bytes, action["hash"].encode())
+            except Exception as e:
+                return False, f"Invalid signature at index {i}: {e}"
+            
+            expected_prev = action["hash"]
+        
+        return True, None
+
+
+# Convenience function
+def create_agent_chain(agent_name: str) -> AgentProvenanceChain:
+    """Create or load an agent provenance chain."""
+    return AgentProvenanceChain(agent_name)
diff --git a/demo.py b/demo.py
new file mode 100644
index 0000000..7a867ed
--- /dev/null
+++ b/demo.py
@@ -0,0 +1,147 @@
+#!/usr/bin/env python3
+"""
+Live demonstration of Agent Provenance Chain.
+
+This script shows Molt (AI agent) signing its own actions in real-time.
+Every operation is cryptographically signed and traceable.
+"""
+
+from apc import create_agent_chain
+import json
+import subprocess
+import os
+
+def main():
+    print("=" * 70)
+    print("🦞 AGENT PROVENANCE CHAIN - LIVE DEMO")
+    print("=" * 70)
+    print()
+    print("Agent: Molt")
+    print("Mission: Demonstrate cryptographic audit trail for AI agents")
+    print()
+    print("-" * 70)
+    
+    # Initialize chain
+    chain = create_agent_chain("molt")
+    
+    print("\n✅ Agent identity established")
+    print(f"   Public Key (first 64 chars):")
+    print(f"   {chain.get_public_key_pem()[:64]}...")
+    print()
+    
+    # Action 1: File write
+    print("📝 ACTION 1: Writing a test file...")
+    test_file = "/tmp/apc_test.txt"
+    with open(test_file, "w") as f:
+        f.write("Hello from Agent Provenance Chain!")
+    
+    action1 = chain.sign_action(
+        action_type="file_write",
+        payload={
+            "path": test_file,
+            "content": "Hello from Agent Provenance Chain!",
+            "bytes": 35
+        },
+        context={
+            "reasoning": "Creating test file to demonstrate signed operations",
+            "session": "demo-2026-02-07"
+        }
+    )
+    
+    print(f"   ✓ Signed at: {action1['iso_time']}")
+    print(f"   ✓ Hash: {action1['hash'][:32]}...")
+    print(f"   ✓ Signature: {action1['signature'][:32]}...")
+    print()
+    
+    # Action 2: Shell execution
+    print("⚙️  ACTION 2: Executing shell command...")
+    result = subprocess.run(["whoami"], capture_output=True, text=True)
+    
+    action2 = chain.sign_action(
+        action_type="shell_exec",
+        payload={
+            "command": "whoami",
+            "exit_code": result.returncode,
+            "stdout": result.stdout.strip(),
+            "stderr": result.stderr.strip()
+        },
+        context={
+            "reasoning": "Checking current user context for audit trail",
+            "risk_level": "low"
+        }
+    )
+    
+    print(f"   ✓ Signed at: {action2['iso_time']}")
+    print(f"   ✓ Hash: {action2['hash'][:32]}...")
+    print(f"   ✓ Previous hash: {action2['previous_hash'][:32]}...")
+    print(f"   ✓ Chain link verified!")
+    print()
+    
+    # Action 3: API call simulation
+    print("🌐 ACTION 3: Simulated API call...")
+    action3 = chain.sign_action(
+        action_type="api_call",
+        payload={
+            "endpoint": "https://api.example.com/data",
+            "method": "GET",
+            "status_code": 200,
+            "response_time_ms": 145
+        },
+        context={
+            "reasoning": "Fetching external data for processing",
+            "data_sensitivity": "public"
+        }
+    )
+    
+    print(f"   ✓ Signed at: {action3['iso_time']}")
+    print(f"   ✓ Hash: {action3['hash'][:32]}...")
+    print()
+    
+    # Verify chain integrity
+    print("🔍 VERIFYING CHAIN INTEGRITY...")
+    is_valid, error = chain.verify_chain_integrity()
+    
+    if is_valid:
+        print("   ✅ Chain is VALID - all signatures verified!")
+        print("   ✅ All actions are cryptographically linked!")
+        print()
+    else:
+        print(f"   ❌ Chain verification FAILED: {error}")
+        print()
+    
+    # Display full chain
+    print("-" * 70)
+    print("COMPLETE AUDIT TRAIL:")
+    print("-" * 70)
+    
+    full_chain = chain.get_chain()
+    for i, action in enumerate(full_chain, 1):
+        print(f"\nAction #{i}:")
+        print(f"  Type: {action['type']}")
+        print(f"  Time: {action['iso_time']}")
+        print(f"  Hash: {action['hash'][:32]}...")
+        print(f"  Payload: {json.dumps(action['payload'], indent=4)}")
+        if action['context']:
+            print(f"  Context: {json.dumps(action['context'], indent=4)}")
+    
+    print()
+    print("=" * 70)
+    print("📊 SUMMARY")
+    print("=" * 70)
+    print(f"Total Actions: {len(full_chain)}")
+    print(f"Chain Valid: {is_valid}")
+    print(f"Agent: molt")
+    print(f"Chain Location: {chain.chain_path}")
+    print()
+    print("🔐 Every action above is:")
+    print("   • Timestamped with microsecond precision")
+    print("   • Cryptographically signed (Ed25519)")
+    print("   • Linked to previous action (blockchain-style)")
+    print("   • Immutable and auditable")
+    print()
+    print("This is how AI agents prove safety without sacrificing speed.")
+    print("=" * 70)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..e30c06f
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1 @@
+cryptography>=42.0.0