refrain

Personal memory for domain-expert agents: git-backed markdown memory per expert (profile, goals, decisions-with-why, session logs, topic notes), exposed two ways — MCP tools at /mcp for in-conversation reads and writes, and an injection digest at /digest for harness hooks (an Open WebUI inlet filter, a Claude Code session hook) to prepend at chat start.

Why

An agent that advises the same user across sessions needs to remember what the user decided and WHY — the one class of data that cannot be rebuilt from any source. Refrain stores exactly that, and nothing else:

• Markdown in a git repo, not database rows: human-legible, human-editable, and git history is the audit trail.
• No vector index: memory holds only the user's own writing and stays small; whole-file reads and grep beat an embedding stack at this scale.
• Single writer, append-or-replace only: every write is a git commit; no delete tool exists — git revert is the undo.
• Two mechanisms: the digest is injected at chat start (a model cannot search for what it doesn't know it forgot); the tools serve deep memory reads and writes during the conversation.

The full rationale is in docs/design.md.

Quickstart

go build -o bin/refrain ./cmd/refrain
REFRAIN_ROOT=$HOME/refrain-memories TARGET_ENV=local ./bin/refrain
curl http://localhost:8092/healthz

The memory root is created (and git init-ed) on first start. Config is env vars: REFRAIN_ROOT (default /data/memories), PORT (default 8092), TARGET_ENV (local keeps text logs; anything else switches to JSON). Requires the git binary on PATH.

For a container deployment see deploy/; for the harness injection hooks see integrations/openwebui/ (Open WebUI inlet filter) and integrations/claudecode/ (Claude Code SessionStart hook).

API

HTTP

Endpoint	Purpose
/mcp	MCP Streamable HTTP: the tools below
GET /digest?expert=<slug>	Injection digest (text/markdown): session context, profile, goals, last 5 decisions, mastery (when state/mastery.json exists), last session log entry — capped to a few hundred tokens
GET /healthz	Liveness

MCP tools

Tool	Purpose
list_experts	Experts with their memory files
read_memory	Read one file in full (they are small — prefer this over search)
search_memory	Grep an expert's files for lines matching any query term
record_decision	Append a dated decision; the why is mandatory
record_note	Append to (or create) a topic note
update_goals	Replace goals.md wholesale
update_profile	Replace profile.md wholesale
append_session_log	Append a dated session summary
set_session_context	Ephemeral scratch context, 24h TTL, outside git
set_state	Store machine-generated structured state (arbitrary JSON) at state/<key>.json, git-committed
get_state	Read back state written by set_state as raw JSON
create_expert	Scaffold a new expert's memory space

Per-expert layout: profile.md, goals.md, decisions.md, log.md, notes/<topic>.md, plus state/<key>.json for machine-written structured state. State lives in git like the rest of memory but is deliberately invisible to search_memory and read_many — it is data, not prose.

Security posture: both endpoints are unauthenticated by design and must only be reachable on a trusted private network. See the warning in deploy/README.md.

Development

make build # bin/refrain
make test# go test -race ./...
make vet
make lint # golangci-lint
make fmt-check