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QMD memory engine

docs/concepts/memory-qmd.md

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QMD is a local-first search sidecar that runs alongside OpenClaw. It combines BM25, vector search, and reranking in a single binary, and can index content beyond your workspace memory files.

What it adds over builtin

  • Reranking and query expansion for better recall.
  • Index extra directories -- project docs, team notes, anything on disk.
  • Index session transcripts -- recall earlier conversations.
  • Fully local -- runs with the optional node-llama-cpp runtime package and auto-downloads GGUF models.
  • Automatic fallback -- if QMD is unavailable, OpenClaw falls back to the builtin engine seamlessly.

Getting started

Prerequisites

  • Install QMD: npm install -g @tobilu/qmd or bun install -g @tobilu/qmd
  • SQLite build that allows extensions (brew install sqlite on macOS).
  • QMD must be on the gateway's PATH.
  • macOS and Linux work out of the box. Windows is best supported via WSL2.

Enable

json5
{
  memory: {
    backend: "qmd",
  },
}

OpenClaw creates a self-contained QMD home under ~/.openclaw/agents/<agentId>/qmd/ and manages the sidecar lifecycle automatically -- collections, updates, and embedding runs are handled for you. It prefers current QMD collection and MCP query shapes, but still falls back to alternate collection pattern flags and older MCP tool names when needed. Boot-time reconciliation also recreates stale managed collections back to their canonical patterns when an older QMD collection with the same name is still present.

How the sidecar works

  • OpenClaw creates collections from your workspace memory files and any configured memory.qmd.paths, then runs qmd update when the QMD manager is opened and periodically afterward (default every 5 minutes). These refreshes run through QMD subprocesses, not an in-process filesystem crawl. Semantic modes also run qmd embed.
  • The default workspace collection tracks MEMORY.md plus the memory/ tree. Lowercase memory.md is not indexed as a root memory file.
  • QMD's own scanner ignores hidden paths and common dependency/build directories such as .git, .cache, node_modules, vendor, dist, and build. Gateway startup does not initialize QMD by default, so cold boot avoids importing the memory runtime or creating the long-lived watcher before memory is first used.
  • If you want a gateway-start refresh anyway, set memory.qmd.update.startup to idle or immediate. The opt-in startup refresh uses a one-shot QMD subprocess path instead of creating the full long-lived in-process watcher.
  • Searches use the configured searchMode (default: search; also supports vsearch and query). search is BM25-only, so OpenClaw skips semantic vector readiness probes and embedding maintenance in that mode. If a mode fails, OpenClaw retries with qmd query.
  • With QMD releases that advertise multi-collection filters, OpenClaw groups same-source collections into one QMD search invocation. Older QMD releases keep the compatible per-collection fallback.
  • If QMD fails entirely, OpenClaw falls back to the builtin SQLite engine. Repeated chat-turn attempts back off briefly after an open failure so a missing binary or broken sidecar dependency does not create a retry storm; openclaw memory status and one-shot CLI probes still recheck QMD directly.
<Info> The first search may be slow -- QMD auto-downloads GGUF models (~2 GB) for reranking and query expansion on the first `qmd query` run. </Info>

Search performance and compatibility

OpenClaw keeps the QMD search path compatible with both current and older QMD installs.

On startup, OpenClaw checks the installed QMD help text once per manager. If the binary advertises support for multiple collection filters, OpenClaw searches all same-source collections with one command:

bash
qmd search "router notes" --json -n 10 -c memory-root-main -c memory-dir-main

This avoids starting one QMD subprocess for every durable-memory collection. Session transcript collections stay in their own source group, so mixed memory + sessions searches still give the result diversifier input from both sources.

Older QMD builds only accept one collection filter. When OpenClaw detects one of those builds, it keeps the compatibility path and searches each collection separately before merging and deduplicating results.

To inspect the installed contract manually, run:

bash
qmd --help | grep -i collection

Current QMD help says collection filters can target one or more collections. Older help usually describes a single collection.

Model overrides

QMD model environment variables pass through unchanged from the gateway process, so you can tune QMD globally without adding new OpenClaw config:

bash
export QMD_EMBED_MODEL="hf:Qwen/Qwen3-Embedding-0.6B-GGUF/Qwen3-Embedding-0.6B-Q8_0.gguf"
export QMD_RERANK_MODEL="/absolute/path/to/reranker.gguf"
export QMD_GENERATE_MODEL="/absolute/path/to/generator.gguf"

After changing the embedding model, rerun embeddings so the index matches the new vector space.

Indexing extra paths

Point QMD at additional directories to make them searchable:

json5
{
  memory: {
    backend: "qmd",
    qmd: {
      paths: [{ name: "docs", path: "~/notes", pattern: "**/*.md" }],
    },
  },
}

Snippets from extra paths appear as qmd/<collection>/<relative-path> in search results. memory_get understands this prefix and reads from the correct collection root.

Indexing session transcripts

Enable session indexing to recall earlier conversations:

json5
{
  memory: {
    backend: "qmd",
    qmd: {
      sessions: { enabled: true },
    },
  },
}

Transcripts are exported as sanitized User/Assistant turns into a dedicated QMD collection under ~/.openclaw/agents/<id>/qmd/sessions/.

Search scope

By default, QMD search results are surfaced in direct and channel sessions (not groups). Configure memory.qmd.scope to change this:

json5
{
  memory: {
    qmd: {
      scope: {
        default: "deny",
        rules: [{ action: "allow", match: { chatType: "direct" } }],
      },
    },
  },
}

When scope denies a search, OpenClaw logs a warning with the derived channel and chat type so empty results are easier to debug.

Citations

When memory.citations is auto or on, search snippets include a Source: <path#line> footer. Set memory.citations = "off" to omit the footer while still passing the path to the agent internally.

When to use

Choose QMD when you need:

  • Reranking for higher-quality results.
  • To search project docs or notes outside the workspace.
  • To recall past session conversations.
  • Fully local search with no API keys.

For simpler setups, the builtin engine works well with no extra dependencies.

Troubleshooting

QMD not found? Ensure the binary is on the gateway's PATH. If OpenClaw runs as a service, create a symlink: sudo ln -s ~/.bun/bin/qmd /usr/local/bin/qmd.

If qmd --version works in your shell but OpenClaw still reports spawn qmd ENOENT, the gateway process likely has a different PATH than your interactive shell. Pin the binary explicitly:

json5
{
  memory: {
    backend: "qmd",
    qmd: {
      command: "/absolute/path/to/qmd",
    },
  },
}

Use command -v qmd in the environment where QMD is installed, then recheck with openclaw memory status --deep.

First search very slow? QMD downloads GGUF models on first use. Pre-warm with qmd query "test" using the same XDG dirs OpenClaw uses.

Many QMD subprocesses during search? Update QMD if possible. OpenClaw uses one process for same-source multi-collection searches only when the installed QMD advertises support for multiple -c filters; otherwise it keeps the older per-collection fallback for correctness.

BM25-only QMD still trying to build llama.cpp? Set memory.qmd.searchMode = "search". OpenClaw treats that mode as lexical-only, does not run QMD vector status probes or embedding maintenance, and leaves semantic readiness checks to vsearch or query setups.

Search times out? Increase memory.qmd.limits.timeoutMs (default: 4000ms). Set to 120000 for slower hardware.

Empty results in group chats? Check memory.qmd.scope -- the default only allows direct and channel sessions.

Root memory search suddenly got too broad? Restart the gateway or wait for the next startup reconciliation. OpenClaw recreates stale managed collections back to canonical MEMORY.md and memory/ patterns when it detects a same-name conflict.

Workspace-visible temp repos causing ENAMETOOLONG or broken indexing? QMD traversal currently follows the underlying QMD scanner behavior rather than OpenClaw's builtin symlink rules. Keep temporary monorepo checkouts under hidden directories like .tmp/ or outside indexed QMD roots until QMD exposes cycle-safe traversal or explicit exclusion controls.

Configuration

For the full config surface (memory.qmd.*), search modes, update intervals, scope rules, and all other knobs, see the Memory configuration reference.