codex

remindb for Codex

Drops remindb into OpenAI Codex as an MCP server. The agent picks up the full remindb__Memory* tool suite, backed by a compiled SQLite view of whatever workspace you point it at.

How it works

Codex treats the repository as a marketplace catalog (.agents/plugins/marketplace.json at the repo root) that lists one plugin, plugins/codex/remindb/. The plugin's .codex-plugin/plugin.json points at sibling .mcp.json, which Codex uses to spawn remindb serve over stdio.

All tool logic lives in the Go binary; the plugin is a thin wrapper.

Installation

1. Install the remindb binary

It needs to be on $PATH:

curl -fsSL https://raw.githubusercontent.com/radimsem/remindb/main/install.sh | bash

On Windows:

iwr -useb https://raw.githubusercontent.com/radimsem/remindb/main/install.ps1 | iex

Verify:

remindb --version

2. Compile a source directory

remindb needs a SQLite file built from a source tree before the agent can read from it.

A natural source for Codex is its own persistent context at ~/.codex/memories/ — markdown files Codex accumulates as long-term memory across sessions. Indexing them lets Codex query its own memory through remindb instead of grepping the dot folder.

mkdir -p ~/.cache/remindb
remindb compile ~/.codex/memories --db ~/.cache/remindb/codex.db

memories/ is pure user content, so no .remindb.ignore is needed. Skills under ~/.codex/skills/ and slash-command prompts under ~/.codex/prompts/ are deliberately not indexed — Codex already loads them as live instructions, so re-indexing them in remindb would double-count. Or point at any other workspace you want the agent to see — a docs tree, a notes repo, a project directory.

3. Point remindb at your workspace

remindb serve reads REMINDB_DB and REMINDB_SOURCE as fallbacks for its --db and --source flags. Codex propagates the launching shell's environment to plugin-spawned MCP subprocesses, so export them in the shell before launching Codex with the plugin enabled — otherwise the first activation falls back to a stray memory.db in cwd:

export REMINDB_DB=$HOME/.cache/remindb/codex.db
export REMINDB_SOURCE=$HOME/.codex/memories

Stick them in ~/.bashrc / ~/.zshrc / your fish equivalent to make it permanent, or scope to a single session if you want to switch workspaces between runs.

If shell-rc isn't an option for you, sidestep the plugin entirely and define a top-level [mcp_servers.remindb] block in ~/.codex/config.toml instead.

Why the workaround? Codex's [plugins.<name>] table only accepts enabled and does no ${VAR} / $VAR / {env:VAR} expansion in either config.toml or the plugin's bundled .mcp.json (which is why the bundled .mcp.json ships with env: {} — placeholders would be passed through literally and override the inherited shell values with garbage). There's no first-class way to inject env into a plugin-bundled MCP server from user config. So:

[mcp_servers.remindb]
command = "remindb"
args = ["serve"]
env = { REMINDB_DB = "/home/you/.cache/remindb/codex.db", REMINDB_SOURCE = "/home/you/.codex/memories" }

Replace /home/you with your absolute $HOME — config.toml does not expand it. This registers remindb as a user-defined MCP server, not a plugin server, so the plugin can stay disabled or removed entirely if you take this path.

4. Add the plugin from GitHub

codex plugin marketplace add radimsem/remindb

That single command does both jobs: the marketplace's policy.installation: INSTALLED_BY_DEFAULT makes Codex install the bundled plugin in the same step. The plugin caches at ~/.codex/plugins/cache/remindb/remindb/<version>/; the marketplace registration lives in ~/.codex/config.toml.

Confirm the server is connected by launching Codex and running the /mcp slash command in the TUI:

/mcp

You should see remindb listed with the full Memory* tool suite. (The codex mcp CLI subcommand only manages external MCP servers added via codex mcp add; plugin-bundled MCP servers surface only inside the TUI.)

Seed remaining context

Step 2 compiled ~/.codex/memories/ — Codex's cross-session notes. The current project's AGENTS.md and in-repo docs (README.md, design notes, roadmaps) live in the repo, not under that path. Ask Codex in your first session to fold them in. Use absolute paths — MemoryCompile doesn't expand ~:

remindb__MemoryCompile(path="/home/you/code/my-project/AGENTS.md", message="seed: project rules")
remindb__MemoryCompile(path="/home/you/code/my-project/README.md", message="seed: project overview")

Re-run whenever a file changes.

Tools exposed

The plugin surfaces the full remindb Memory* tool suite under the remindb__ namespace. See the main README for the canonical tool list and per-tool token-savings benchmarks.

License

MIT — same as remindb.