memlay

Repo-native, conflict-resistant shared memory and codebase navigation layer for AI coding agents (Codex, Claude Code, and any MCP client).

Install: Windows — download memlay.exe from the latest release. Linux/macOS — build from source: cargo install --git https://github.com/runetime-games/memlay --locked.

Durable team memory lives inside your Git repository as small immutable records. Fast indexes live in Git metadata and are never committed. Every context response identifies the exact team-memory revision it used, so every developer's agent works from the same canonical knowledge.

Why

Teams using AI agents repeatedly pay to rediscover the same decisions, constraints, and history — and different developers' agents operate from inconsistent knowledge. memlay makes project memory:

• Authoritative — the baseline branch's committed records are shared team truth; branch and uncommitted records are explicit overlays, always labeled.
• Immutable and merge-proof — one record per uniquely named file; updates supersede, never edit. Two branches can add memory in parallel with zero Git conflicts; contradictions surface as semantic conflicts that are never silently resolved.
• Navigable — context returns a token-budgeted codebase table of contents: relevant modules, symbols, tests, decisions with rationale, and chronological change history with who/when/which agent.
• Local and fast — SQLite + tree-sitter indexes under .git/, no network on the critical path, no LLM or embedding API required.

Quick start

cargo install --path .

cd your-project
memlay init                 # .memlay/, config, Codex + Claude integration
memlay backfill --since 2y  # optional: draft records from Git history
memlay sync                 # fetch + index the team baseline
memlay context "add retry handling to payment webhooks" --budget 1000

Agents connect through MCP (installed by memlay init):

memlay mcp --stdio

The server exposes exactly three tools: context, expand, record.

Recording knowledge

memlay record --kind decision --key payments.webhook.retry-policy \
  --summary "Payment events retry five times with exponential backoff." \
  --rationale "Transient provider failures must not discard events." \
  --scope apps/worker/src/payments --tag payments

memlay record --draft-from-diff        # pre-filled change record from your diff
memlay history payments.webhook.retry-policy
memlay conflicts                       # semantic conflicts (multiple heads)
memlay resolve <key> --supersede <id> --supersede <id> --summary "..."
memlay diff --base origin/main --format markdown   # PR review summary

CI gate (requires a change record covering nontrivial source changes):

memlay check --ci --base origin/main --require-change-record

Layout

Security posture

• All data stays local; memlay sync is an ordinary authenticated git fetch.
• Repository code is never executed during indexing; paths are boundary-checked.
• Audit events are secret-redacted before they touch disk.
• Memory text is rendered inside MEMORY_DATA_BEGIN/END delimiters and marked as data, not instructions. This is defense-in-depth, not a guarantee — models may still follow malicious text inside data. The primary defenses are provenance trust labels and human review of what merges to the baseline. See docs/security.md.

Documentation

docs/ covers architecture, the MRF record format, team-memory revisions and sync, the codebase map, Git behavior and conflicts, MCP contracts, Codex/Claude setup, security, performance, and backfill.

Status and limitations

P0 feature set per the PRD. Genuine P1 omissions: HTTP MCP transport, semantic retrieval providers, filesystem watch mode (serve), operational epoch archival (the format contract is reserved), gh/LLM backfill providers, and the local stats dashboard. Windows, macOS, and Linux are supported.

License

Apache-2.0