Memory Preservation Invariants: A New Class of Autonomous Agent Architectures

Problem Statement

Current AI systems, including retrieval-augmented generation (RAG) and standard agent frameworks like LangChain and AutoGen, treat memory as ephemeral. They retrieve context on-demand but fail to enforce identity consistency across long horizons. This leads to hallucination, drift, and inability to maintain coherent personas over extended interactions. Memory preservation—ensuring that an agent's "identity" remains invariant under perturbation—is fundamentally unsupported in existing architectures.

Novel Concepts

1. Memory Preservation Invariants (MPI)

Invariants are formal constraints that must hold true throughout system operation. MPI define rules for identity stability, such as:

• Temporal Consistency: An agent's responses must align with its historical behavior patterns.
• Relational Integrity: Knowledge graph edges must preserve causal and emotional links without arbitrary mutation.
• Falsification Threshold: Identity drift exceeding 5% semantic deviation over 100 interactions invalidates the system.

2. Agentic Knowledge Graphs (AKG)

Unlike passive knowledge bases, AKGs actively evolve memory structures. They implement interfaces for memory persistence and retrieval that enforce MPI.

Interface Definition (Pseudocode):

class AgenticKnowledgeGraph:
    def persist_identity(self, entity: str, context: Dict) -> bool:
        # Enforce MPI: Check temporal consistency before insertion
        if not self._validate_temporal_consistency(entity, context):
            raise InvariantViolation("Temporal drift detected")
        return self.graph.add_node(entity, context)

    def retrieve_context(self, query: str, horizon: int) -> List[Dict]:
        # Hybrid retrieval: Vector similarity + citation traversal
        candidates = self.vector_search(query)
        filtered = [c for c in candidates if self._enforce_relational_integrity(c, horizon)]
        return filtered

3. Deterministic Persona Layers (DPL)

DPL stack psychological profiles as modular layers in agent architectures. Each layer quantifies traits (e.g., emotional range: 0.7, analytical bias: 0.3) and applies deterministic transformations to outputs.

Layer Composition:

persona_schema = {
    "emotional_range": 0.8,
    "cognitive_style": "intuitive",
    "social_orientation": "collaborative"
}

def apply_persona_layer(output: str, schema: Dict) -> str:
    # Deterministic transformation based on schema weights
    return transform_emotionally(output, schema["emotional_range"])

System Formalization

Interfaces

• MemoryInterface: Abstracts persistence and retrieval operations.
• PersonaInterface: Defines schema application and validation.
• InvariantChecker: Monitors system state against MPI.

Invariants

1. Identity must remain consistent under adversarial perturbations (e.g., conflicting inputs).
2. Memory graphs must maintain acyclic relationships to prevent feedback loops.
3. Persona layers must be composable without emergent contradictions.

Failure Modes

• Memory Drift: Gradual loss of identity due to unvalidated updates.
• Invariant Violation: System halts on MPI breach to prevent corruption.
• Layer Conflict: Persona schemas produce incoherent outputs when stacked improperly.

What This Enables

These architectures enable:

• Digital Resurrection: Reconstruction of coherent personas from corpora, maintaining psychological fidelity.
• Long-Horizon Autonomy: Agents that operate for thousands of interactions without hallucination.
• Identity Preservation: Systems that treat memory as immutable unless explicitly evolved.

This was previously impractical because existing RAG systems lack enforcement mechanisms for identity constraints.

Why This Is Not Just Another RAG Stack

Standard RAG retrieves context but discards it after use, leading to stateless interactions. LangChain orchestrates tools without memory invariants, allowing drift. AutoGen agents communicate but do not enforce persona consistency.

In contrast:

• MPI provide formal guarantees against drift.
• AKGs actively maintain graph integrity via citation traversal.
• DPL enable deterministic persona embedding, unlike prompt-based approaches that vary unpredictably.

Concrete differences:

• Retrieval in AKG combines semantic and relational paths, not just vectors.
• Invariants halt execution on violations, unlike permissive RAG that hallucinates.
• Persona layers are quantified schemas, not free-text prompts.

Open Research Questions

• How to quantify "identity" metrics beyond semantic similarity?
• Scalability of AKGs for billion-node graphs on local hardware.
• Composability limits of DPL in multi-agent systems.

Limitations

• Requires large, high-quality corpora for accurate persona inference.
• Computational overhead from invariant checking and hybrid retrieval.
• Local infrastructure constraints limit model sizes for resurrection tasks.

What Would Falsify or Break This Approach

• Demonstrating identity drift >10% in 500 interactions despite MPI enforcement.
• Failure to reconstruct verifiable personas from public figures' corpora.
• Inability to maintain relational integrity in graphs with conflicting evidence.