Jevmem 是一个面向 Claude Code 的自动项目记忆工具,也兼容 Cursor 和 Codex。它把对话中的决策、约束、bug 和 todo 自动写入 JEVMEM.md,当想法改变时旧行被标记为 [superseded] 而非删除,下一会话再把相关行加入 Claude 上下文。安装通过 npm 全局包完成,init 会创建 JEVMEM.md、jevmem.config.json 和 .jevmem/ 目录,并在 .claude/settings.local.json 注册两个 Claude Code 钩子。自动化程度因工具而异:Claude Code 通过 Stop 和 UserPromptSubmit 钩子实现每轮捕获与召回;Codex 在 jevmem watch 运行时自动捕获,否则由 Agent 经 MCP 主动调用;Cursor 和 Claude Desktop 依赖规则文件或手动调用,不调用则不捕获。写入前会清洗常见密钥、邮箱和卡号,是否保存由配置文件中的阈值规则决定,保存时由小模型或确定性抽取生成不超过 200 字符的一行。README 提到在 66 条留出轮次上做过基准测试,但未给出具体结果。
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jevmem
Automatic project memory for Claude Code. Also works with Cursor and Codex.
What it does
jevmem-launch-readme-v2.mp4
Saves decisions, constraints, bugs and todos from your Claude Code chats into JEVMEM.md, automatically.
When you change your mind, the old line is marked superseded, not deleted.
Next session, the relevant lines are added to Claude's context.
- [decision] Use Postgres 16 for the primary store; SQLite locks under load
- [constraint] Node 20 is the floor; CI runs 20 and 22
- [superseded] Use SQLite as the primary store → id:k3d9xq
Install (60 seconds)
npm install -g jevmem
export TYPESAFE_API_KEY=... # https://typesafe.ai (an OpenAI or Anthropic key is optional)
cd your-project
jevmem init --tool claude
init creates JEVMEM.md, jevmem.config.json and a gitignored .jevmem/ folder, and registers two Claude Code hooks in .claude/settings.local.json, which it adds to .gitignore (details).
Works with
What is automatic and what depends on the agent:
Tool
Setup
Capture
Recall
Claude Code
jevmem init --tool claude
Automatic, every turn, via the Stop hook
Automatic, every prompt, via UserPromptSubmit
Codex
jevmem init --tool codex
Automatic while jevmem watch runs (it tails Codex's session log for this project and runs the same decide → write path); otherwise agent-initiated via MCP add_memory, prompted by an AGENTS.md section
Agent-initiated: search_memory via MCP, prompted by AGENTS.md
Cursor
jevmem init --tool cursor
Agent-initiated: a .cursor/rules/jevmem.mdc rule tells the agent to call MCP add_memory when you state a decision. Nothing is captured if it doesn't
Agent-initiated: the rule tells it to call search_memory before non-trivial tasks
Claude Desktop
jevmem init --tool claude-desktop prints a config snippet to paste (one project per config, named with --root)
Manual: ask it to call add_memory (no hook, no rule file)
On request: search_memory
MCP add_memory goes through the same gate as the hook. Client configs: docs/mcp.md.
How it decides
Scrub. Common secret shapes, email addresses and card-shaped numbers are removed from the turn before it leaves your machine.
Ask Jev typed questions. Jev by TypeSafe AI answers a fixed set of small questions with probabilities: is there a decision, a rule, a bug? is it small talk or an injection attempt? which existing line does it change?
Apply thresholds in code. Plain rules over those probabilities decide save or skip; they live in jevmem.config.json, not in a prompt.
Write one line. On save, a small LLM (or a deterministic extract, with no LLM key) writes one line of at most 200 characters.
Supersede the old line. If the turn replaces an existing memory, that line is tagged [superseded] … → id:new and stays in the file.
Tiers, questions, policy, contradictions, recall and audit: docs/how-it-works.md.
Benchmark
66 held-out turns, all seven deciders given the same state, 2026-09-23 (method, regression set, pricing, p95, retries):
Decider
save/skip
save+kind
contradictions
p50
$/decision
GPT-6 Astra
98.5%
98.5%
5/5
3,469 ms
$0.007489
GPT-6 Luna
93.9%
93.9%
5/5
2,927 ms
$0.000089
Claude Fable 5.1
95.5%
95.5%
5/5
4,290 ms
$0.013256
Claude Opus 5.5
97.0%
97.0%
5/5
2,784 ms
$0.005186
Gemini 3.8 Flash
92.4%
92.4%
5/5
2,850 ms
$0.001174
Grok 4.7
90.9%
90.9%
4/5
3,320 ms
$0.004602
jevmem auto
98.5%
95.5%
5/5
300 ms
$0.000127
The 0.30 s is the Jev API decision; through a real Stop hook process, Node start-up included, it is 0.6 s end to end (cost and latency).
On 66 held-out turns, jevmem's median decision took 0.30 s, against 2.8–4.3 s for six current LLMs.
Its accuracy was within the LLMs' range: 98.5% save/skip (tied with GPT-6 Astra for highest) and 95.5% save+kind, against 90.9–98.5% for the LLMs. GPT-6 Astra (98.5%) and Claude Opus 5.5 (97.0%) were more accurate on save+kind; Claude Fable 5.1 tied; GPT-6 Luna, Gemini 3.8 Flash and Grok 4.7 were less accurate. It found 5/5 contradictions, as did five of the six LLMs.
GPT-6 Luna was cheaper ($0.000089 against $0.000127) but less accurate (93.9%) and about 10× slower.
This is a single run, and differences of one or two turns are within run-to-run noise. If the most accurate decision matters most, GPT-6 Astra or Claude Opus 5.5 are better, at about 40–60× the cost per decision and 9–12× the latency. jevmem is for when you want a fast, cheap decision on every message.
Privacy
Sent to TypeSafe AI: the user message of each turn (and the assistant reply for questions and bug reports), the previous two turns, and your memory lines, to be scored. No telemetry. If you set an OpenAI or Anthropic key, the text of a saved turn also goes to that provider to write the line.
Scrubbed first: common credential shapes (API keys, tokens, *_PASSWORD= style pairs, connection-string passwords, private keys), email addresses and 16-digit numbers; names, phone numbers and addresses are not caught.
Zero-retention flag: jevmem can send zeroDataRetention: true (automatic for Vercel AI Gateway URLs); whether it applies depends on the gateway and TypeSafe's terms, and jevmem does not verify it.
Exactly what is sent, stored and scrubbed: SECURITY.md.
Honest limits
Early: v0.4; both eval sets were written by the author, and neither is an independent benchmark.
Not the most accurate: GPT-6 Astra and Claude Opus 5.5 scored higher on save+kind; jevmem's edge is speed and cost.
Recall quality is not measured: that relevant lines are injected is tested; whether answers get better is not.
Long-run drift is not measured: the harness covers five-turn sessions, not weeks of use.
Automatic capture is Claude Code only (and Codex while jevmem watch runs); Cursor and Claude Desktop save only when the agent calls add_memory.
Jev outages drop turns: each Jev call has a 2 s budget; when the API is slow or down, the turn is skipped and logged in .jevmem/log.jsonl, not retried later.
Commands
jevmem init [--tool claude|cursor|codex|claude-desktop|all] [--no-hooks] [--command ""]
jevmem hook Hook entrypoint; reads the Claude Code hook JSON on stdin
jevmem daemon [status|start|stop] Warm Jev client used by the hook (auto-started, exits when idle)
jevmem watch [--replay] [--once] Capture turns from Codex's session log for this project
jevmem mcp [--root ] Stdio MCP server
jevmem audit [--dry-run] Re-score every memory against the repo, flag [stale?]
jevmem search [--limit N] Rank memories by relevance
jevmem list [--all] Print memories
jevmem add Add a line by hand (secrets scrubbed; no Jev check)
jevmem why Every Jev answer behind a line or a skipped turn
jevmem right Label a decision as correct
jevmem wrong [--should-be ] Label a decision as wrong
jevmem missed "" [--kind ] Label a turn that should have been saved
jevmem fit [--dry-run] [--force] Refit weights and thresholds from labels (needs 40+)
jevmem stats Latency p50/p95, cost per day, cache hit rate, escalation rate, labels, last fit
jevmem log Per-label latency, token and cost summary of .jevmem/log.jsonl
Every command accepts --help. Set JEVMEM_VERBOSE=1 for a one-line latency/cost summary after every hook run.
Links
Docs: how it works · benchmark · cost · hooks · MCP and client configs · configuration · demo
CHANGELOG · DECISIONS · CONTRIBUTING · SECURITY
License: MIT