Atlas / MCP servers / kael-bit / Engram

EngramSAFE

mcp/kael-bit/engram-4

Memory engine for AI agents — time axis (3-layer decay/promotion) + space axis (self-organizing topic tree). Hybrid search, LLM consolidation. Single Rust binary.

Verdict
SAFE
Grade
B
Trust score
89 /100
Exposed tools
16 11r · 4w · 1d
Transport
stdio
License
MIT
Stars
28
01

Overview

From the repository's own README, as read at the audited commit. Badges and raw HTML are left out.

[](https://github.com/kael-bit/engram-rs/actions/workflows/ci.yml) [](LICENSE) [](https://www.rust-lang.org) [](https://github.com/kael-bit/engram-rs) [](https://ghcr.io/kael-bit/engram-rs)

Memory engine for AI agents. Two axes: time (three-layer decay & promotion) and space (self-organizing topic tree). Important memories get promoted, noise fades, related knowledge clusters automatically.

Most agent memory is a flat store — dump everything in, keyword search to get it back. No forgetting, no organization, no lifecycle. engram-rs adds the part that makes memory actually useful: the ability to forget what doesn't matter and surface what does.

Single Rust binary, one SQLite file, zero external dependencies. No Python, no Redis, no vector DB — curl | bash and it runs. ~10 MB binary, ~100 MB RSS, single-digit ms search latency.

Quick Start

# Install (interactive — will prompt for embedding provider config)
curl -fsSL https://raw.githubusercontent.com/kael-bit/engram-rs/main/install.sh | bash

# Store a memory
curl -X POST http://localhost:3917/memories \
-d '{"content": "Always run tests before deploying", "tags": ["deploy"]}'

# Recall by meaning
curl -X POST http://localhost:3917/recall \
-d '{"query": "deployment checklist"}'

# Restore full context (session start)
curl http://localhost:3917/resume

What It Does

Thr

Read from source at commit a1baad63cf62OBSERVED · 2026-10-08
02

Connect

Built from this server's own package name, version and transport as found in its source — not copied from anyone's documentation, so it cannot drift against a page we do not control. Replace the environment placeholders with a token scoped to the least it needs.

claude-code (npm)
claude mcp add engram-rs-mcp --env ENGRAM_API_KEY=${ENGRAM_API_KEY} -- npx -y [email protected]
03

Exposed tools (16)

11 read · 4 write · 1 destructive. Blast radius: 1 tool can delete or overwrite — an agent that can be talked into calling a tool can be talked into calling this one.

ToolRiskDescription
engram_consolidatewriteRun a memory consolidation cycle. Promotes important memories upward,
engram_deletedestructiveDelete a memory by ID. Use when a memory is outdated, incorrect, or redundant.
engram_extractreadExtract structured memories from raw text using LLM.
engram_healthreadDetailed health check: uptime, RSS memory, embed cache stats, AI config status.
engram_recallreadHybrid semantic + keyword search with budget-aware retrieval.
engram_recentreadList recent memories by creation time. Good for session context recovery.
engram_repairreadRepair FTS search index. Removes orphaned entries and rebuilds missing ones.
engram_restorereadRestore a soft-deleted memory from trash back to its original layer.
engram_resumereadFull memory bootstrap for session recovery. Returns core (permanent knowledge),
engram_searchreadQuick keyword search. Lighter than recall — no scoring or budget logic.
engram_statsreadGet memory statistics: counts per layer, AI status, version.
engram_storewriteStore a memory. All memories start in Buffer and promote to Working/Core through
engram_topicreadDrill into topic clusters by ID. Use after /resume to explore specific topics from the knowledge index.
engram_trashreadList soft-deleted memories. Recently deleted items can be restored.
engram_triggerswriteFetch trigger memories for a specific action. Call before performing an action (e.g. git-push, deploy) to recall relevant lessons and rules.
engram_updatewriteUpdate a memory
04

Trust audit

SAFEgrade B · trust 89/100 Nothing in the source contradicts what it says it does. Grade A is reserved for packages that have also passed the behavioural sandbox.

LayerWhat it checksResult
L0Provenance & inventoryPASS
L1Static analysis of the codePASS
L2Instruction surface (what it tells the agent)PASS
L3Class-specific surfaceWARN
L4Behavioural (sandbox)SKIPPED

What the source does

Filesystem
declared (8 observation(s))
Network
declared (10 observation(s))
Shell
none-observed
Dependencies
not all pinned
Secrets in source
none-found

Findings (10)

MEDIUMFilesystem / path · mcp.destructive_tools · CWE-22, CWE-59
engram_delete
Why it matters. 1 tool(s) can delete or overwrite
Fix. prefer a read-only mode or scoped tokens; the page states the blast radius
LOWFilesystem / path · fs.traversal · CWE-22, CWE-59
src/api/mod.rs:189
axum::response::Html(include_str!("../../web/index.html"))
LOWFilesystem / path · fs.traversal · CWE-22, CWE-59
src/api/mod.rs:195
include_str!("../../web/style.css"),
LOWFilesystem / path · fs.traversal · CWE-22, CWE-59
src/api/mod.rs:205
include_str!("../../web/app.js"),
LOWSupply chain · supply.unpinned · CWE-829, CWE-1357
mcp/package.json
@modelcontextprotocol/sdk, zod, typescript, @types/node
Why it matters. 4 dependency range(s) float
Fix. pin exact versions or ship a lockfile
LOWSupply chain · prompt.pipe_to_shell · CWE-829, CWE-1357
README.md:17
Single Rust binary, one SQLite file, zero external dependencies. No Python, no Redis, no vector DB — `curl | bash` and it runs. ~10 MB binary, ~100 MB RSS, single-digit ms search latency.
LOWSupply chain · prompt.pipe_to_shell · CWE-829, CWE-1357
README.md:23
curl -fsSL https://raw.githubusercontent.com/kael-bit/engram-rs/main/install.sh | bash
LOWSupply chain · prompt.pipe_to_shell · CWE-829, CWE-1357
README.md:198
curl -fsSL https://raw.githubusercontent.com/kael-bit/engram-rs/main/install.sh | bash
LOWSupply chain · prompt.pipe_to_shell · CWE-829, CWE-1357
README_CN.md:12
单个 Rust 二进制,一个 SQLite 文件,零外部依赖。不需要 Python、Redis、向量数据库——`curl | bash` 即装即用。~10 MB 二进制,~100 MB 内存占用,毫秒级搜索延迟。一台 $5 VPS 就能跑。
LOWSupply chain · prompt.pipe_to_shell · CWE-829, CWE-1357
README_CN.md:24
curl -fsSL https://raw.githubusercontent.com/kael-bit/engram-rs/main/install.sh | bash

Gates applied: no_behavioural_pass.

Audited 2026-10-08 · audit v0.4.1 · source sha a1baad63cf62full audit observations/trust-audit/mcp-server/kael-bit__engram-4.json · Report an issue / request a re-scan
05

Audit history

Every audit this server has had. A grade with a past is a grade somebody is still checking.

DateSourceVerdictGradeScoreChange
2026-10-08a1baad63cf62SAFEB89first audit
06

Questions

What is the Engram MCP server?

Memory engine for AI agents — time axis (3-layer decay/promotion) + space axis (self-organizing topic tree). Hybrid search, LLM consolidation. Single Rust binary.

What tools does Engram expose?

16 in total: 11 read-only, 4 that write, and 1 that can delete or overwrite (engram_delete). Every one is listed on this page with its risk.

Is Engram safe to connect to an agent?

The audit found nothing in the source that contradicts what it says it does, and graded it B (89/100). Grade A is held back for packages that have also passed a sandboxed behavioural run, which is why a clean server reads B. Separately from the audit: 1 of its tools can destroy data, so scope the token you give it to what you actually need.

What credentials does Engram need?

It reads ENGRAM_API_KEY from the environment. Give it a token scoped to the least it needs — an agent that can be talked into calling a tool can be talked into calling it with your credentials.

How does Engram run?

It speaks stdio, so it runs as a local process your client starts. It is published on npm as engram-rs-mcp at 0.14.0.

How current is this page?

The grade is for one exact copy of the source (a1baad63cf62), read on 2026-10-08. The repository is watched and re-audited when it changes.

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