memtrust-cli 0.3.0

Independent, reproducible benchmark harness for agent-memory backends

memtrust

Standardized, reproducible benchmarks for agent-memory backends, run against the vendors, not published by them.

pip install memtrust
memtrust run --backends mempalace,mem0,zep,openviking --eval all

(For contributing to this repo instead of just running it, see Development -- pip install -e ".[dev]" from a clone.)

Contents: Why this exists · What it does · Commands · How this differs · Contradiction detection · Compression fidelity · Temporal-KG boundary · The landscape · Benchmarks · GitHub Actions usage · Self-host · Install · Hosted layer · Backend coverage · Development · License · Success stories

Why this exists

If you've compared agent-memory backends recently, you've probably noticed each one leads with a different accuracy number, on a different benchmark, measured a different way. MemPalace's own community already flagged the problem in public. Issue #27 on the MemPalace repository, opened April 7, 2026 and still open, documents a widely-cited 100% LongMemEval score that came from hand-tuning on the failed test questions themselves. The held-out score is 98.4%, not 100%. A separate 96.6% figure people cite everywhere turns out to be mostly ChromaDB's default embeddings doing the work, not MemPalace's own architecture. A "lossless" compression claim drops accuracy by 12.4 percentage points in practice. Two internal pull requests attempting to fix the reporting problem (#433 and #729) were both closed without merging on April 12, 2026. As of this writing, the issue has 233 thumbs-up reactions and 39 comments.

None of that means MemPalace, or any other backend, doesn't work. It means nobody outside the vendor had run the same test, the same way, against every option, and published the raw logs.

memtrust does that. It runs LongMemEval, LoCoMo, and a growing set of evals built specifically for this project -- 14 of them as of this writing, registered in the CLI's --eval flag, plus a fifteenth (temporal-KG boundary detection) that exists as a tested module but isn't wired into the CLI yet. The two that matter most for understanding what this project is actually for: contradiction detection, because neither LongMemEval nor LoCoMo tests the question that actually matters once a memory system sits underneath a production agent -- what happens when a new fact contradicts an old one? Does the backend flag the conflict? Silently overwrite the old fact with no audit trail? Serve whichever version it happens to retrieve first? None of the four backends this project tracks publish a number for that. And compression/round-trip fidelity, built to directly test claims like the "lossless" one above: it stores content, retrieves it, and scores literal reconstruction fidelity rather than semantic accuracy, per operating mode a backend exposes (see MemoryBackendAdapter.supported_modes) -- the mechanism that would let a contributor with live MemPalace credentials actually reproduce the 12.4-point compressed-mode accuracy drop mempalace/mempalace#27 documents, instead of just citing it. Neither has been run against any live backend as of this writing -- see docs/methodology.md. The other evals -- ranking quality, crash recovery, extraction quality, embedding drift, scale/volume stress, lock contention, stats accuracy, orphan cleanup, result consistency, migration rollback, filter injection, resource-sync safety, and temporal-KG boundary detection -- each grew out of a specific real bug report against one of the four tracked backends; see "Success stories" below for the full list.

What it does

Every command below was actually run against this repo, with zero vendor API keys configured, to produce the output shown. Nothing here is simulated.

$ memtrust run --backends mempalace,mem0,zep,openviking --eval all
memtrust 0.1.0 -- run_id=mt_2026-07-17T155402Z
Backends: mempalace, mem0, zep, openviking   Evals: longmemeval, locomo, contradiction,
resource_sync_safety, compression, ranking_quality, scale_stress, embedding_drift, crash_recovery,
extraction_quality, migration_rollback, filter_injection, lock_contention, stats_accuracy,
orphan_cleanup, result_consistency

mempalace: SKIPPED (not configured) -- mempalace is not configured: environment variable
MEMPALACE_STORAGE_PATH is not set. Skipping this backend. See docs/methodology.md for setup
instructions.
mem0: SKIPPED (not configured) -- mem0 is not configured: environment variable MEM0_API_KEY is not
set. Skipping this backend. See docs/methodology.md for setup instructions.
zep: SKIPPED (not configured) -- zep is not configured: environment variable ZEP_API_KEY is not set.
Skipping this backend. See docs/methodology.md for setup instructions.
openviking: SKIPPED (not configured) -- openviking is not configured: environment variable
OPENVIKING_API_KEY is not set. Skipping this backend. See docs/methodology.md for setup
instructions.

Cost: $0.00 (no LLM-judged evals ran -- structural evals only, or judge not configured)

Full report: memtrust-report-2026-07-17.json

That's the real, reproducible behavior of a fresh clone with no credentials: every backend reports SKIPPED, the command exits cleanly, and a valid JSON report is still written. memtrust --version currently prints 0.1.0 even though the package installs as 0.2.0 on PyPI -- a stale hardcoded string in src/memtrust/__init__.py that hasn't caught up with pyproject.toml, shown here exactly as it actually runs rather than smoothed over. Set the relevant environment variable for any backend you want to actually test (MEM0_API_KEY, ZEP_API_KEY, OPENVIKING_API_KEY, MEMPALACE_STORAGE_PATH) and that backend runs for real against its live API instead of being skipped.

The eval logic itself is proven offline, against the bundled synthetic fixtures and, for several adapters, the real installed vendor packages with only the network boundary mocked, by the test suite:

$ pytest --cov=memtrust --cov-report=term-missing
...
Name                                                          Stmts   Miss  Cover
-------------------------------------------------------------------------------------
src/memtrust/adapters/base.py                                   290      1    99%
src/memtrust/adapters/mempalace_adapter.py                      265     15    94%
src/memtrust/adapters/mem0_adapter.py                            140     12    91%
src/memtrust/adapters/mem0_direct_adapter.py                     281     34    88%
src/memtrust/adapters/openviking_adapter.py                      178     18    90%
src/memtrust/adapters/zep_graphiti_adapter.py                     63      3    95%
src/memtrust/adapters/zep_graphiti_selfhosted_adapter.py         165     24    85%
src/memtrust/evals/contradiction.py                              127      2    98%
src/memtrust/evals/compression.py                                 86      1    99%
src/memtrust/evals/temporal_kg_boundary.py                        90      4    96%
src/memtrust/receipt.py                                          118     10    92%
-------------------------------------------------------------------------------------
TOTAL                                                            4130    256    94%

580 passed, 8 skipped in 3.31s

580 passing tests across 33 source modules, 94% overall statement coverage, 98% on the contradiction-detection eval, 99% on compression/round-trip fidelity, 96% on the new temporal-KG boundary eval, 94-99% across the adapter layer. The 8 skips are live-mempalace-package tests that only run with the optional mempalace-direct extra installed (pip install -e '.[dev,mempalace-direct]'). Every test mocks its HTTP or wire layer, or uses an in-memory fake backend -- none of them touch a real network, though a meaningful share of the adapter tests now import and exercise real installed vendor classes directly (mem0ai==2.0.12's embedder and vector-store modules, and -- gated behind the optional mempalace-direct extra -- the real mempalace.mcp_server functions), mocking only the outermost network or wire-client boundary rather than the whole library. graphiti-core is not installed in this environment, so its self-hosted adapter's tests still run against a hand-written Protocol double built to match the real package's confirmed method signatures, not the real classes -- see docs/methodology.md's adapter confidence table for exactly which claim rests on which kind of verification.

Commands

$ memtrust --help
Usage: memtrust [OPTIONS] COMMAND [ARGS]...

  memtrust: an independent, reproducible benchmark harness for agent-memory
  backends.

Options:
  --version  Show the version and exit.
  --help     Show this message and exit.

Commands:
  keygen  Generate a new Ed25519 keypair for signing `memtrust run`...
  report  Read a prior `memtrust run` JSON report and print a formatted...
  run     Run the eval suite against the requested backends.
  verify  Verify a signed receipt produced by `memtrust run --sign`.

Command	Flags	What it does
memtrust run	--backends TEXT comma-separated list or all (default all) · --eval TEXT comma-separated from longmemeval,locomo,contradiction,resource_sync_safety,compression,ranking_quality,scale_stress,embedding_drift,crash_recovery,extraction_quality,migration_rollback,filter_injection,lock_contention,stats_accuracy,orphan_cleanup,result_consistency, or all (default all) · --output FILE (defaults to ./memtrust-report-<date>.json) · --locomo-dataset-path FILE points the LoCoMo eval at a real, downloaded locomo10.json instead of the bundled synthetic fixture (memtrust does not bundle or auto-fetch the real dataset) · --locomo-exclude-question-ids-file FILE excludes known-bad-ground-truth LoCoMo question IDs from scoring · --scale-stress-n-records INTEGER (default 500) sets how many synthetic records the scale-stress eval stores and re-queries · --sign FILE writes a signed <output>.receipt.json alongside the report, proving it was produced by the holder of the given Ed25519 private key	Runs the eval suite against the requested backends. A backend without its credential env var set prints SKIPPED and the run continues -- this command never crashes on missing credentials.
memtrust report REPORT_PATH	positional path to a prior JSON report	Reads a report written by memtrust run and prints a formatted summary.
memtrust keygen	--	Generates a new Ed25519 keypair for signing reports with run --sign.
memtrust verify RECEIPT_PATH	--	Verifies a signed receipt produced by memtrust run --sign; a tampered or mismatched receipt fails verification.
memtrust --version	--	Prints the installed version. Currently prints 0.1.0, one release behind the 0.2.0 this package actually installs as -- see the note above.

The temporal-KG boundary eval (src/memtrust/evals/temporal_kg_boundary.py, run_temporal_kg_boundary_eval()) is not yet wired into --eval's known-eval list -- it exists as a tested module and a MemPalace-specific capability, callable directly, not yet a memtrust run --eval temporal_kg_boundary option. See its own section below.

Every line above came straight from running memtrust --help, memtrust run --help, and memtrust report --help against this repo. Nothing here is invented.

How this differs from trusting a vendor's own numbers

Every backend memtrust tracks publishes its own benchmark numbers. None of them publish the same benchmark, scored the same way, with the same held-out discipline. memtrust doesn't ask you to trust it instead: it asks you to read the raw logs. Every run's methodology, prompt templates, dataset versions, and scoring rubric are published in docs/methodology.md, versioned alongside the code that produced them. If the methodology has a flaw, it's a flaw you can point to in a specific file and line, not something buried in a vendor's internal eval pipeline.

General-purpose LLM eval frameworks (promptfoo, DeepEval, RAGAS, and similar tools) are mature and widely used, but none of them ship a memory-backend adapter abstraction or a contradiction- detection eval out of the box -- they're built for RAG quality, red-teaming, and general prompt evaluation, not for comparing how different memory systems handle a fact that changes over time. memtrust is narrower and more specific on purpose.

The landscape (verified, not benchmarked)

Real, publicly checkable numbers as of this writing (gh api repos/<org>/<repo>), not memtrust-run scores -- accuracy and contradiction-handling comparisons stay in the "Benchmarks" section below until a live run actually produces them:

Backend	GitHub stars	Self-reported description
MemPalace	57,268	"The best-benchmarked open-source AI memory system. And it's free."
Mem0	60,688	"Universal memory layer for AI Agents"
Zep / Graphiti	28,648	"Build Real-Time Knowledge Graphs for AI Agents"
OpenViking	26,639	"Self-evolving Context Database for AI Agents. Unify Agent Memory, Knowledge RAG and Skills."

None of these numbers say anything about which backend handles a contradicted fact correctly -- that's the whole reason the harness exists. Star count measures adoption, not correctness.

The eval that actually matters: contradiction detection

LongMemEval and LoCoMo both measure recall: can the backend remember a fact you told it earlier. That's necessary but not sufficient. The harder question is what a backend does when two facts conflict: you tell it your meeting is at 2pm, then later say it moved to 3pm. Does it flag the change? Overwrite silently? Serve whichever one it retrieves first? memtrust's classifier stores a fact, stores a contradicting fact, queries for it, then checks the actual retrieved content for both values, rather than trusting whatever conflict signal the adapter itself reports. See src/memtrust/evals/contradiction.py and the scoring-logic section of docs/methodology.md for exactly how that classification works.

The eval built for the other headline overclaim: compression fidelity

mempalace/mempalace#27 documents two separate overclaims, not one: the LongMemEval score gap described above, and a "lossless" compression claim that measured 12.4 percentage points lower in practice under a compressed operating mode. memtrust could not previously reproduce that second number at all -- there was no way to tell an adapter "run this under mode X vs mode Y" through the shared interface. MemoryBackendAdapter.store()/query() now accept an optional mode: str | None parameter, and MemoryBackendAdapter.supported_modes lets an adapter declare which mode strings it actually understands (MemPalaceAdapter.supported_modes is ("raw", "AAAK"), the two names mempalace/mempalace#27 itself uses -- see src/memtrust/adapters/mempalace_adapter.py for the exact provenance and confidence caveat on those names). Adapters with no mode variants accept and ignore the parameter, so this is a purely additive, backward-compatible interface change.

src/memtrust/evals/compression.py runs the same store-then-retrieve round trip once per mode a backend reports, and scores each round trip with a direct, deterministic character-level similarity ratio (fidelity_ratio(), via difflib.SequenceMatcher -- not an LLM judge, since a "lossless" claim is a literal-reconstruction claim, not a semantic one). This is what would let a contributor with live MemPalace credentials point memtrust run --eval compression at it and reproduce a "raw vs AAAK" fidelity gap directly. As of this writing this eval has not been run against any live backend -- see docs/methodology.md for the same live-credentials caveat that applies to every other eval in this table.

The eval built from MemPalace's own bug: temporal-KG boundary detection

MemPalace/mempalace#1913 (fixed by merged PR#1914, contributor ggettert) described a real, concrete bug: _temporal_filter_sql's as_of point-in-time query used a closed interval on both ends, so a fact whose valid_to equaled the query's exact as_of instant still matched. Hand-roll a fact change as kg_invalidate(ended=T) immediately followed by kg_add(valid_from=T) at the identical boundary instant -- the exact pattern MemPalace's own pre-fix agent guidance told every caller to do -- and an as_of=T query returns both the just-ended fact and its just-started successor at once, so a single-valued fact reports two contradictory answers with no error. src/memtrust/evals/temporal_kg_boundary.py reproduces that exact hand-rolled sequence against MemPalaceAdapter's kg_add()/kg_invalidate()/kg_query() and classifies the result with a new TemporalBoundarySignal taxonomy, distinct from ConflictSignal and RankingSignal because it concerns one narrow, structurally different failure: two facts sharing one instant, not a contradiction across time or a ranking-order question.

Honest scope, stated the same way this project states it for every other eval: the real mempalace PyPI package is not installed in this build environment, and PR#1914's fix had not shipped in a released mempalace version as of this adapter's live-verified 3.5.0 build -- it lands under the package's [Unreleased] changelog section. tests/test_temporal_kg_boundary.py proves the classification logic is correct against two hand-written fake implementations that reproduce the confirmed pre-#1914 (closed-interval) and post-#1914 (half-open-interval) SQL comparison exactly. This has not been run against a live MemPalace instance. It also isn't wired into memtrust run --eval yet -- call run_temporal_kg_boundary_eval() directly, or see the test suite, until that CLI surface exists.

Benchmarks

Not yet measured against live backends. This repo was built without API credentials for MemPalace, Mem0, Zep, or OpenViking. Publishing a number here without actually running the harness against a live backend would be exactly the kind of unverifiable claim this project exists to push back on, so there isn't one.

To produce real numbers:

export MEM0_API_KEY=...          # and/or
export ZEP_API_KEY=...
export OPENVIKING_API_KEY=...
export MEMPALACE_STORAGE_PATH=...
export MEMTRUST_JUDGE_API_KEY=...   # needed for LongMemEval/LoCoMo grading; contradiction-detection doesn't need it

memtrust run --backends mempalace,mem0,zep,openviking --eval all
memtrust report memtrust-report-<date>.json

The command prints per-backend accuracy and contradiction-handling rates, writes a full JSON report, and prints an estimated cost for any LLM-judged evals that ran. MemPalaceAdapter's drawer and knowledge-graph calls are now live-verified against a real installed instance (see "Backend coverage" below), but OpenViking's memory-write/query paths, and parts of the self-hosted Mem0 and Zep/Graphiti adapters, are still built against best-effort interpretations of documented or source-read product concepts rather than a live-confirmed API -- see the confidence table in docs/methodology.md before treating any adapter's output as authoritative, and consider that table's gaps a standing invitation to contribute a fix.

Labeling requirement for any future accuracy figure published here. LongMemEval and LoCoMo accuracy grades the LLM judge's verdict on raw retrieved-record content directly -- there is no answer-generation step in either eval runner. This is not the same measurement as the official LongMemEval/LoCoMo leaderboards' generate-then-judge QA-accuracy scores. Any accuracy number this project publishes for those two evals must be labeled "retrieval-graded accuracy," not bare "accuracy," and must not be directly compared to leaderboard figures without that caveat. See docs/methodology.md's "Retrieval-graded accuracy vs. generated-answer accuracy" section.

GitHub Actions usage

Run the suite on a schedule and publish results to the leaderboard:

name: memtrust-leaderboard
on:
  schedule:
    - cron: "0 9 * * 1"  # weekly
  workflow_dispatch: {}

jobs:
  benchmark:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: "3.12"
      - run: pip install memtrust
      - run: memtrust run --backends mempalace,mem0,zep,openviking --eval all --output leaderboard/data.json
        env:
          MEM0_API_KEY: ${{ secrets.MEM0_API_KEY }}
          ZEP_API_KEY: ${{ secrets.ZEP_API_KEY }}
          OPENVIKING_API_KEY: ${{ secrets.OPENVIKING_API_KEY }}
          MEMTRUST_JUDGE_API_KEY: ${{ secrets.MEMTRUST_JUDGE_API_KEY }}
      - run: git add leaderboard/data.json && git commit -m "Update leaderboard" && git push

This repo's own CI (.github/workflows/ci.yml) runs lint, type-check, test, and a dependency security audit on every push and pull request -- no vendor credentials required, since every test runs fully offline.

Self-host

git clone https://github.com/RudrenduPaul/memtrust
cd memtrust
pip install -e ".[dev]"
export MEM0_API_KEY=...
memtrust run --backends mem0 --eval all

Point an adapter at your own backend, or run the suite against your own conversation data instead of the bundled synthetic fixtures (see docs/methodology.md's note on swapping in the real LongMemEval/LoCoMo datasets). Nothing leaves your machine unless you choose to publish it.

Install

npx (agent-native)

PyPI is live; the npm wrapper is publish-ready but not yet published. pip install memtrust works today -- version 0.2.0 is on PyPI. The memtrust-cli npm package in npm/memtrust-cli/ in this repo is built, tested, and passes both npm pack --dry-run and npm publish --dry-run cleanly (re-verified this session), but has not actually been pushed to the npm registry yet -- npm install memtrust-cli still 404s as of this writing. The command below is the real, working distribution path once that publish happens; nothing about it is speculative except the "it's live on npm" part.

For CI and agent runners that have Node.js available but not necessarily a Python toolchain:

npx memtrust-cli run --backends mempalace,mem0,zep,openviking --eval all

The npm package is named memtrust-cli so it is unambiguous as a CLI tool at a glance (and so it doesn't collide with any future memtrust JS library package). npx always resolves the package name to its matching bin entry automatically, so npx memtrust-cli ... is what reliably works for a zero-install first run. Once installed, the package also exposes the shorter memtrust command as a second bin alias -- matching the underlying Python CLI's own command name -- so you are not stuck typing memtrust-cli for every subsequent invocation; memtrust run ... works too.

This is not a zero-dependency install: npx memtrust-cli still fetches memtrust from PyPI on first use. What it removes is no Python toolchain to provision by hand -- npx memtrust-cli handles the interpreter and package fetch for you via a bundled, verified copy of Astral's uv. Each platform package bundles a genuine, SHA-256-verified copy of uv's own GitHub release binary (fetched at npm package-publish time, never at end-user install time), and its bin shim runs uv tool run --from memtrust memtrust <args>, which transparently bootstraps a Python interpreter and installs memtrust from PyPI, caching it after the first run.

What a hosted trust layer would add

The harness, adapters, and leaderboard in this repo are the entire OSS surface, and they're sufficient on their own to compare backends. A hosted layer on top of this -- described here, not built -- would add continuous regression monitoring that re-runs the suite automatically whenever a tracked backend ships a new release, private scorecards that run the same methodology against a team's own data shape instead of the public sample fixtures, and a compliance-report export for teams whose security or legal review needs a documented third-party artifact rather than a free-text summary. None of that exists yet. If it's ever built, it stays additive to the free harness, never a requirement for using it.

Backend coverage

The MemPalace row below used to say "needs verification against a live instance" -- it needed more than that. Every prior version of MemPalaceAdapter called a mempalace.Palace class (Palace(storage_path=...) exposing .remember()/.recall()/.invalidate()) that never existed in the real, installed package. python3 -c "import mempalace; hasattr(mempalace, 'Palace')" returns False; grepping every class definition across the installed package turns up nothing named Palace anywhere. Every test that appeared to pass before this rewrite was exercising a hand-written fake standing in for that guess, never the real thing -- store()/query()/ update() had never actually worked against a live MemPalace install, in this project's entire history, until this rewrite. src/memtrust/adapters/mempalace_adapter.py was rewritten from scratch against the real, plain module-level functions in mempalace.mcp_server (tool_add_drawer, tool_search, tool_update_drawer, tool_delete_drawer, tool_kg_add/tool_kg_invalidate/tool_kg_query) -- every return shape documented in the adapter's module docstring was captured by calling those functions live against a real, local chromadb-backed palace, not read off a docstring and trusted. It's the kind of mistake this whole project exists to catch in other people's benchmarks; finding it in memtrust's own adapter and shipping the fix in the open, rather than quietly patching it, is the more useful story.

Backend	Adapter status	Confidence (see docs/methodology.md)
MemPalace	Implemented -- drawer API + knowledge-graph API	High on the real mempalace.mcp_server functions this adapter now calls, live-verified against an installed mempalace 3.5.0 instance (see above). Still best-effort on compression-mode names ("raw"/"AAAK") and on whether degraded_retrieval warnings are ever populated by the installed version -- see the adapter's module docstring for both caveats stated plainly.
Mem0	Implemented -- hosted Platform API, self-hosted OSS server, and a direct in-process library adapter	High on the hosted Platform API and on what the installed mem0ai==2.0.12 library's embedder/vector-store code actually does (confirmed by reading its real source, exercised directly in tests); medium-high on the self-hosted OSS server's route shape (confirmed from source, not run against a live server).
Zep / Graphiti	Implemented -- hosted Zep Platform API and a self-hosted graphiti-core adapter	Medium-high on the hosted API's documented contradiction-handling behavior; medium on the self-hosted adapter's wire-level shape (every method signature confirmed by reading graphiti-core's real source, not by running it against a live Neo4j/FalkorDB instance -- the package isn't installed in this environment).
OpenViking	Implemented	Medium on architecture, low on exact memory-write/query paths -- still the adapter most likely to need correction against a live instance.

Adding a backend adapter is the primary contribution path -- see CONTRIBUTING.md.

Development

pip install -e ".[dev]"
ruff check . && ruff format --check .
mypy --strict src/memtrust
pytest --cov=memtrust --cov-report=term-missing --cov-fail-under=80
pip-audit

.pre-commit-config.yaml wires ruff and mypy into pre-commit if you'd rather run these on every commit than remember to run them by hand.

License

Apache 2.0. See LICENSE.

Success stories

197 real issues/PRs filed by real contributors against MemPalace, mem0, Zep/Graphiti, and OpenViking have been independently root-caused against this codebase: does the solution, as it actually exists today, let you diagnose or resolve what was reported? 55 (28%) verify as a clean PASS, 16 (8%) as PARTIAL (evidence captured, needs a human to interpret further, or only part of the issue is covered), 42 (21%) as a genuine capability gap this harness doesn't close yet, and 84 (43%) as not actually applicable (feature requests, already-fixed-upstream, or genuinely out of scope). Every verdict below has been re-verified live against the current codebase by a reviewer independent of whoever built the fix, not just cited from a changelog. Full write-ups and validation evidence are tracked internally; the summary here is for anyone deciding whether this harness would have caught their own bug.

The headline story is about memtrust's own bug, not a vendor's. Every version of MemPalaceAdapter before this rewrite called a mempalace.Palace class -- Palace(storage_path= ...) exposing .remember()/.recall()/.invalidate() -- that never existed in the real, installed package. python3 -c "import mempalace; hasattr(mempalace, 'Palace')" returns False; nothing named Palace appears anywhere in the installed package's source. Every test that appeared to pass was exercising a hand-written fake standing in for that guess -- store()/query()/ update() had never once worked against a live MemPalace install. src/memtrust/adapters/ mempalace_adapter.py was rewritten against the real mempalace.mcp_server functions, with every documented return shape captured by calling them live against a real local instance. A project built to catch other vendors overclaiming found the same failure mode in its own code, and the fix shipped in the open rather than quietly. See "Backend coverage" above for the full account.

MemPalace

• #1754 (@rodboev): a checkpoint recovery fix for silently quarantined dim-None pickles. memtrust's contradiction eval couldn't previously tell "silently quarantined" apart from "no update primitive at all"; it now can (ConflictSignal.EMPTY_OR_LOST).
• #1929 (@jrzmurray): a fix for NUL bytes silently corrupting a ChromaDB index. memtrust's store() used to trust "no exception" as proof of a durable write; an opt-in read-after-write verification step now catches this.
• #1450 (@lealbrunocalhau): a fix for an empty embedding response getting scored as a wrong answer instead of flagged as infra failure. Same fix as #1754 above.
• #1823 / #1543 (@fatkobra): lock and write-integrity fixes that pointed at the same read-after-write gap #1929 closed.
• #1913 / PR#1914 (@ggettert): a temporal-KG as_of boundary bug where a fact ending at exactly the query instant still matched alongside its successor. memtrust's new temporal-KG boundary eval reproduces the exact hand-rolled kg_invalidate()-then-kg_add() sequence that triggers it -- see "The eval built from MemPalace's own bug" above for the honest not-yet-live-verified caveat.
• PR#1890 / #1889 (@JosefAschauer): an authored_at chronology tie-break fix for _hybrid_rank. memtrust's ranking classifier now credits a top-level authored_at field, not just one nested under metadata, as a genuine ranking-driving signal.
• #524 (@gaby): a buried-comment report that "no API key required" doesn't mean "no network required" -- ChromaDB's default embedder still needs to download a model on first use, which silently breaks airgapped setups. The adapter's module docstring now says so explicitly.

mem0

• #5973 (@abhay-codes07, superseded by #5992): an empty-string entity-id filter scoping bug. memtrust's mem0 adapter only reached the hosted Platform API and had no delete operation at all, so it couldn't have caught this. A self-hosted adapter with tested delete/delete_many primitives now can.
• #4297 (@utkarsh240799): a dimension auto-detection fix. The self-hosted adapter now routes to the right deployment, though no test yet reproduces this specific bug end to end, so this one is partial, not fully caught.
• #4573 (@jamebobob): a 32-day audit of 10,134 real mem0 entries finding 97.8% junk. memtrust's new extraction-quality eval and ExtractionQualitySignal taxonomy cover the audit's own junk categories, including its 808-duplicate feedback-loop case.
• PR#5980 (@HrushiYadav): a filter-injection fix for the Elasticsearch vector store. A new filter-injection eval exercises the real, installed mem0.vector_stores.elasticsearch.ElasticsearchDB._validate_filter() directly and confirms it rejects the exact malicious filter shape ({"user_id": {"$ne": ""}}) this PR fixed.
• #4956 (@NDNM1408): an open proposal that mem0's add-only pipeline surfaces stale, contradictory facts with no recency signal. memtrust's contradiction eval now runs the same literal add-only scenario (two store() calls, no explicit update) against this taxonomy.
• #4884 (@wangjiawei-vegetable): a hardcoded English-only tokenizer silently degrading non-Latin-script retrieval. A new LanguageDegradationSignal and non-Latin-script fixtures now catch this shape.

Zep / Graphiti

• #1489 (@brentkearney): a bi-temporal invalid_at correctness gap. memtrust's contradiction classifier used to discard Graphiti's own invalid_at metadata and infer everything from a fixed top-5 text match, misreading a correctly flagged case as a silent overwrite. It now checks the metadata first.
• #1275 (@rafaelreis-r, still open): O(n) entity-resolution context growth silently dropping episodes past roughly 300 ingested. A new self-hosted graphiti-core adapter plus a scale/volume-stress eval now tracks a fixed "anchor" record's recall across ascending checkpoints against real add_episode() ingestion -- the same shape this issue describes.
• #836 (@matthiaslau) / #920 (@markwkiehl): two separate crashes in update_communities()/resolve_edge_contradictions() -- a too-many-values-to-unpack error and a tz-naive/aware datetime comparison error. A new CrashSignal classification recognizes both exact shapes instead of surfacing an opaque generic exception.
• PR#1222 (@david-morales) / PR#1183 (@Milofax): FalkorDB RediSearch syntax errors from empty or unescaped fulltext queries. A new CrashSignal.QUERY_SANITIZATION_ERROR recognizes both issues' verbatim filed error text.
• #1467 (@elimydlarz, open, zero engagement): GeminiEmbedder silently returning the wrong vector count. A new CrashSignal.EMBEDDING_BATCH_COUNT_MISMATCH catches this once Gemini embedder support is wired into the self-hosted adapter.

OpenViking

• #3029 (@dfwgj, still open): Feishu resync silently deleting user-managed files. memtrust had no way to observe this failure mode at all; a dedicated resource-sync-safety eval now seeds generated and user files, triggers a resync, and checks what survives.
• #2850 (@lg320531124, still open): BM25 search silently returning empty results at scale. A dedicated scale/volume-stress eval (memtrust run --eval scale_stress) now stores a large synthetic corpus and re-queries it at ascending checkpoints to reproduce the shape of this condition -- recall collapsing past a volume threshold with no exception raised.
• #1581 (@0xble, fix rejected, still live upstream): v2_lock_max_retries=0 silently means unlimited retries, not zero. A new lock-contention eval asserts a bounded response-time budget under concurrent-write contention.
• #1255 (@SeeYangZhi): a stats endpoint silently returning zero despite persisted memories. A new get_stats()/StatsResult primitive and dedicated stats-accuracy eval now catch this.
• #2966 (@lRoccoon, unaddressed upstream): legacy uint16-truncated records that are permanently undeletable. A new CrashSignal.LEGACY_CORRUPT_RECORD_UNDELETABLE now surfaces this instead of a silent no-op.
• #204 (@ponsde, closed): non-deterministic search results (Jaccard similarity 0.11 across identical queries) from a self-diagnosed dimension mismatch. A new result-consistency eval computes pairwise Jaccard similarity over repeated identical queries to catch this class directly.

Cross-project

• OneNomad-LLC/przm-bench (@mattstvartak): a peer benchmarking project shipped cryptographic receipt signing; memtrust had none. memtrust now has real Ed25519 signing/verification (the cryptography library, not a hand-rolled scheme) via memtrust keygen / run --sign / verify -- a tampered receipt correctly fails verification, a genuine one correctly passes.

Several PARTIAL and FAIL -- capability gap rows above and elsewhere in the full 197-row set remain open, deliberately not counted as fixed: some point at real gaps this harness genuinely can't close yet without a live vendor credential, and inflating a near-miss to PASS defeats the entire point of an independently-verified benchmark. See the confidence caveats throughout this README and in docs/methodology.md for exactly which claims rest on which kind of evidence.