EngramaBench: Evaluating Long-Term Conversational Memory with Structured Graph Retrieval

AuthorsJulian Acuna

2026

TL;DR

EngramaBench shows that Engrama’s graph-structured memory activation and typed answers reach 0.6532 cross space score, beating GPT-4o full-context’s 0.6291 at much lower cost.

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THE PROBLEM

Long-term assistants still forget structured cross-space memories (Mem0 only scores 0.5266 cross space)

Large assistants are expected to retain weeks of history, yet Mem0 reaches only 0.5266 cross space accuracy and 0.2848 single space on EngramaBench.

This means long-term conversational systems mis-handle cross-space integration, temporal change, and adversarial abstention, limiting trustworthy multi-session collaboration.

HOW IT WORKS

EngramaBench and Engrama’s graph memory surface

EngramaBench probes Engrama’s Graph Memory, Memory activation, Neighborhood retrieval, Structured summary, and Typed answer layer over multi-session personas and semantic spaces.

Think of EngramaBench as a stress test where Engrama plays the hippocampus, organizing life events into an indexed graph instead of a raw transcript dump.

This structured surface lets Engrama recover configurations of related facts and abstain on fabricated queries in ways a plain context window cannot.

DIAGRAM

EngramaBench query flow over multi-session histories

This diagram shows how EngramaBench feeds persona histories and queries into Engrama’s ingestion and retrieval pipeline for evaluation.

DIAGRAM

EngramaBench dataset and evaluation pipeline

This diagram shows how EngramaBench constructs personas, conversations, queries, and scores Engrama against GPT-4o full-context and Mem0.

PROCESS

How Engrama Handles a Multi-session Query on EngramaBench

  1. 01

    Ingestion and Consolidation

    Engrama processes timestamped conversations, extracting entities, relations, and events, and attaches them into a consolidated graph memory surface.

  2. 02

    Graph Memory Organization

    Engrama organizes entities, semantic spaces, temporal traces, and associative links so work, family, and other regions remain distinct yet connected.

  3. 03

    Query-conditioned Memory Activation

    Engrama uses memory activation, including Lever 1’s entity-first activation and query planner, to select a relevant subregion of the graph.

  4. 04

    Neighborhood Retrieval and Answer Composition

    Engrama performs neighborhood retrieval, builds a structured summary, and applies the typed answer layer (Lever 3) to generate precise answers.

KEY CONTRIBUTIONS

Key Contributions

  • 01

    EngramaBench benchmark for long-term conversational memory

    EngramaBench defines five personas, 100 conversations, and 150 queries across single space, cross space, temporal cross space, adversarial, and emergent insight behaviors.

  • 02

    Controlled comparison of memory architectures

    EngramaBench compares GPT-4o full-context, Engrama, and Mem0 using GPT-4o as the shared answering model, isolating memory architecture effects on composite and per-family scores.

  • 03

    Ablation analysis of Engrama’s design levers

    EngramaBench studies Lever 1 and Lever 3, showing composite changes up to +0.0134 and cross space drops up to −0.0546, revealing a tradeoff between specialization and global optimization.

RESULTS

By the Numbers

Composite score

0.5367

−0.0819 vs GPT-4o full-context’s 0.6186

Cross space

0.6532

+0.0241 over GPT-4o full-context’s 0.6291

Single space

0.5997

−0.1342 vs GPT-4o full-context’s 0.7339

Query-time cost

$0.67

about −$2.66 vs GPT-4o full-context’s $3.33 across 150 queries

On EngramaBench full v1, which tests long-term conversational memory across five task families, Engrama trades a lower composite score for a higher 0.6532 cross space score and much lower query-time cost than GPT-4o full-context.

BENCHMARK

By the Numbers

On EngramaBench full v1, which tests long-term conversational memory across five task families, Engrama trades a lower composite score for a higher 0.6532 cross space score and much lower query-time cost than GPT-4o full-context.

BENCHMARK

Main results on EngramaBench full v1 (150 queries, 5 personas)

Composite score on EngramaBench full v1.

BENCHMARK

Cross space performance comparison on EngramaBench

Cross space score (n=30 queries).

KEY INSIGHT

The Counterintuitive Finding

Engrama’s Lever 3 removal raises composite to 0.5501 yet drops cross space from 0.6532 to 0.6033, a −0.0499 change on the most diagnostic slice.

This is surprising because you’d expect a stronger typed answer layer to help globally, but EngramaBench shows it mainly benefits structured cross-space reasoning rather than aggregate score.

WHY IT MATTERS

What this unlocks for the field

EngramaBench gives builders a controlled way to see how graph-structured memory like Engrama changes behavior on cross-space, temporal, adversarial, and synthesis queries.

With these measurements, system designers can tune memory activation, retrieval, and typed answer layers to target specific long-term behaviors instead of chasing a single undifferentiated long-context score.

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