Session amnesia
Each new Claude Code or Codex session starts without the context you already earned.
Persistent memory for Claude Code and Codex
Stop re-explaining your project every new session.
A single Rust binary that automatically captures, distills, and injects project context across sessions: decisions, patterns, preferences, and learnings.
- Single Rust binary
- Localhost only
- SQLCipher at rest
- MIT licensed
The problem
Every new session starts from zero.
Context you spent hours building disappears the moment the thread ends.
Lost rationale
Design decisions and bug-fix root causes vanish when the session ends.
Preference fatigue
The same project preferences get repeated instead of carried forward.
No continuity
Long-running work is hard to resume with confidence after context compaction or a fresh session.
How it works
Hooks into your agents. Nothing to capture by hand.
remem records raw session evidence, distills it in the background, then serves compact memory back through hooks and MCP.
Claude Code
SessionStart
Inject relevant project memory and preferences.
Claude Code
UserPromptSubmit
Register sessions and flush stale queues.
Claude Code
PostToolUse
Queue tool observations without blocking the workflow.
Claude Code / Codex
Stop
Summarize and promote durable memories in the background.
Search architecture
Four retrieval channels, fused.
A query is routed through BM25, entities, temporal parsing, and LIKE fallback, then merged with Reciprocal Rank Fusion.
- Project-scoped search prevents cross-project leakage.
- CJK segmentation and Chinese-English synonym expansion improve recall.
- Title-weighted BM25 and topic-key dedup keep results compact.
"database encryption"
FTS5 BM25
Entity index
Temporal
LIKE fallback
RRF = sum 1 / (60 + rank)
Top-K merged memories
Product proof
The memory arrives before the work begins.
The site ships with the repository's existing terminal demo asset, so the first release uses real project media instead of stock visuals.
Benchmarks
Measured, not hand-waved.
Published README snapshots cover LoCoMo, internal retrieval, and local QA evaluation.
v2 optimized, session summary ingest, gpt-5.4.
Internal eval over 1,777 real memories.
Internal retrieval hit rate.
Project-scoped search validation.
Usage & cost
Measured locally, reported as estimates.
remem records AI usage for its own background extraction, summaries, compression, and promotion calls. The CLI reports token usage and estimated USD cost by day, week, source, project, and executor.
- Provider/log usage is separated from text-estimated fallback rows.
- Cost is an estimate, not a provider invoice or subscription bill.
- Executor and model selection live in ~/.remem/config.toml.
- The local audit below is a snapshot from 2026-06-06; usage varies by workload.
remem usage --days 14 --weeks 8
Daily and weekly totals
Project-scoped reports
Usage source precision
Estimated USD cost
provider/log rows stay separate from estimates
cost estimate, not invoice
This repository's remem ledger was $6.18 against $17,595.10 of total agent spend.
All remem background memory calls across projects were $437.15 in the same window.
Estimated background memory cost for this repository over 8 weeks.
ccstats all-source spend over the same 2026-04-12 to 2026-06-06 window.
Install
Use the same commands as the README.
Start with Homebrew, the prebuilt GitHub Release installer, or Cargo. Then restart your coding agent.
curl -fsSL https://raw.githubusercontent.com/majiayu000/remem/main/install.sh | shGive Claude Code and Codex a memory.
Single binary. Local store. Durable context for long-running engineering work.