OpenViking Memory Plugin for Codex

Long-term semantic memory for Codex, powered by OpenViking.

This is the Codex counterpart to claude-code-memory-plugin. It hooks Codex's lifecycle to:

• Auto-recall relevant memories on every UserPromptSubmit and inject them via hookSpecificOutput.additionalContext
• Incremental capture on Stop (turn end): append the new user/assistant turns to a deterministic OpenViking session id cx-<codex_session_id>. When pending_tokens reaches OPENVIKING_COMMIT_TOKEN_THRESHOLD, commit while keeping a recent live tail.
• Commit on PreCompact: trigger OpenViking's memory extractor on the full pre-compact transcript before Codex summarizes it.
• Commit on SessionStart (source=startup|clear): active-window heuristic — if exactly one other state file was touched within the last 2 min, commit it (the just-ended session). On ≥2, defer to idle-TTL sweep at the tail. source=resume never commits or sweeps; if the live OV session was already committed, it may inject the latest archive summary for continuity. See DESIGN.md for the full decision tree.

It also starts a local stdio MCP proxy that forwards to OpenViking's native /mcp endpoint with credentials resolved from env / ovcli.conf, so the model has direct access to the search, store, read, list, grep, glob, forget, add_resource, and health tools.

Quick Start

There are two install paths. Pick one — don't mix them (both surface the same openviking-memory plugin; enabling it from both would run the hooks twice). The one-line installer (A) is the recommended path for most users; the marketplace install (B) is useful when you already manage ~/.openviking/ovcli.conf yourself.

A. One-line installer — curl | bash (recommended)

bash <(curl -fsSL https://raw.githubusercontent.com/volcengine/OpenViking/main/examples/memory-plugin-shared/install.sh) --harness codex

Claude Code and Codex share this installer (drop --harness codex to pick interactively). It asks for your language (English/中文), the download source (GitHub, or a TOS mirror for GitHub-blocked regions — pass --dist tos; Codex on TOS installs from a TOS-hosted git repo and keeps remote updates), and your OpenViking credentials. It:

1. Checks codex and Node.js 18+ (the plugin itself wants Codex's bundled Node 22+ at runtime)
2. Sets up ~/.openviking/ovcli.conf interactively
3. Registers the openviking marketplace — remote git by default (codex plugin marketplace add https://github.com/volcengine/OpenViking.git), or this checkout / a TOS archive in dev/archive mode — and enables openviking-memory@openviking with features.plugin_hooks = true
4. Keeps the checked-in stdio .mcp.json intact; servers/mcp-proxy.mjs reads your active ovcli.conf at runtime
5. Removes old OpenViking rc wrapper blocks and the pre-unification openviking-plugins-local marketplace when found
6. Runs plugin-list and stdio MCP validation

After install:

codex             # first run: review /hooks once

B. Codex marketplace install

This path uses the same checked-in stdio MCP proxy as the installer path. Authenticated and remote/cloud servers work when ~/.openviking/ovcli.conf or the relevant OPENVIKING_* env vars are present in Codex's environment.

The repo ships a Codex marketplace catalog at .agents/plugins/marketplace.json, so you can install with Codex's native commands:

# 1. add the OpenViking marketplace (use volcengine/OpenViking once merged
#    upstream, or <your-fork>/OpenViking while testing a fork)
codex plugin marketplace add volcengine/OpenViking

# 2. install the plugin from that marketplace
#    (older Codex builds spell this `codex plugin install`)
codex plugin add openviking-memory@openviking

Then enable plugin hooks (if your Codex build doesn't already) by adding to ~/.codex/config.toml:

[features]
plugin_hooks = true

Finally start Codex and trust the plugin hooks once:

codex            # then run /hooks inside Codex to review & approve the hooks

Requirements & notes

• Codex version: this path relies on Codex injecting and inline-substituting ${PLUGIN_ROOT} in plugin hook commands (current Codex does both). On an older Codex that doesn't substitute ${PLUGIN_ROOT}, the hook script paths won't resolve — use path A.
• Catalog source: the catalog entry (.agents/plugins/marketplace.json) uses a relative source (./examples/codex-memory-plugin). codex plugin add therefore installs the plugin from the same marketplace snapshot/ref that you added. This keeps fork, branch, tag, and upstream-main installs reproducible and testable without rewriting the catalog.

This path works out of the box against an unauthenticated local OpenViking at http://127.0.0.1:1933. For remote/cloud servers, create ~/.openviking/ovcli.conf with url, api_key, and optional account / user; the proxy reads it when Codex starts.

Manual setup

If you don't want the installer touching your rc, do these things yourself:

1. Write ovcli.conf once so hooks and MCP share the same connection:

   jsonCopy

   {
     "url": "https://your-openviking-server.example.com",
     "api_key": "<your-api-key>",
     "account": "my-team",
     "user": "alice"
   }
   

   Or run the bundled interactive wizard: node scripts/setup.mjs (from the plugin directory).

2. Add the plugin via the remote marketplace (path B above), or via a local directory marketplace: codex plugin marketplace add <checkout>/examples reads examples/.agents/plugins/marketplace.json and yields the same openviking-memory@openviking id. hooks/hooks.json needs no rendering on modern Codex: it uses the native ${PLUGIN_ROOT} token, which Codex injects into the hook env and substitutes inline.

Configuration

Connection / identity source (applies to hooks, MCP, and ov commands run inside Codex):

1. Default: active ovcli.conf wins when present: OPENVIKING_CLI_CONFIG_FILE or ~/.openviking/ovcli.conf. Use ov config switch <name> to change the active credentials for the CLI, hooks, MCP, and child ov commands together.
2. Env-forced: set OPENVIKING_CREDENTIAL_SOURCE=env to force OPENVIKING_URL / OPENVIKING_BASE_URL, OPENVIKING_API_KEY / OPENVIKING_BEARER_TOKEN, OPENVIKING_ACCOUNT, OPENVIKING_USER, and OPENVIKING_PEER_ID.
3. Fallback: without an ovcli config, env vars are used; then ov.conf (server.url / server.root_api_key plus legacy codex.* tuning); then http://127.0.0.1:1933 unauthenticated.

Hooks and the MCP proxy call the same resolver directly, so the model tools and lifecycle hooks follow the same target.

Auth is sent as Authorization: Bearer <api_key> to both the REST API (used by hooks) and the /mcp endpoint (used by the model).

Set actor_peer_id in ovcli.conf (or OPENVIKING_PEER_ID with OPENVIKING_CREDENTIAL_SOURCE=env) when multiple Codex peers share the same OpenViking user and should keep separate peer memory. Hooks pass it as peer_id for captured session messages and as X-OpenViking-Actor-Peer for retrieval/filesystem calls; MCP gets the same header mapping. The legacy codex.peerId / codex.peer_id fields in ov.conf still resolve as a fallback.

The checked-in .mcp.json contains only a stdio command. It never stores server URLs, bearer-token env mappings, or identity headers, so switching ovcli.conf changes the MCP target on the next Codex launch without cache rendering.

Tuning the plugin

All plugin behavior is controlled by OPENVIKING_* environment variables. Connection and identity should normally live in ovcli.conf; tuning vars can be exported in your shell rc when you want every Codex launch to pick them up.

# ~/.zshrc — examples
export OPENVIKING_RECALL_LIMIT=6
export OPENVIKING_RECALL_COMPRESS=1
export OPENVIKING_RECALL_COMPRESS_MODEL=gpt-5.3-codex-spark
export OPENVIKING_RECALL_COMPRESS_THINKING=default
export OPENVIKING_RECALL_TIMEOUT_MS=120000
export OPENVIKING_CAPTURE_ASSISTANT_TURNS=1
export OPENVIKING_AUTO_COMMIT_ON_COMPACT=1
export OPENVIKING_DEBUG=1

Full list: see the Misc env vars block in scripts/config.mjs. Tuning fields have OPENVIKING_* counterparts and env vars win for those tuning fields.

Legacy codex block in ov.conf

Earlier plugin versions configured tuning fields under a codex block in ~/.openviking/ov.conf. That still works for backward compat — every env var above has a camelCase counterpart (OPENVIKING_RECALL_LIMIT → codex.recallLimit, etc.) — but new deployments should prefer env vars: this is the codex CLI's per-machine plugin tuning, and the server-side ov.conf is the wrong place for it. (It's read from ov.conf, not ovcli.conf, by historical accident in scripts/config.mjs.)

Architecture

   ┌──────────────────────────────────────────────────────────────┐
   │                            Codex                             │
   └──┬─────────────────┬────────────────┬───────────────────┬────┘
      │                 │                │                   │
 SessionStart      UserPromptSubmit    Stop              PreCompact
 (startup|clear|resume) │              (per turn)            │
      │                 │                │                   │
 ┌────▼──────────┐ ┌────▼──────┐ ┌──────▼──────┐ ┌──────────▼──────┐
 │ session-start │ │ auto-     │ │ auto-       │ │ pre-compact-    │
 │ -commit.mjs   │ │ recall.mjs│ │ capture.mjs │ │ capture.mjs     │
 │ (active-win   │ │ (search + │ │ (append +   │ │ (commit + reset │
 │ heuristic +   │ │ compress) │ │ threshold   │ │ ovSessionId)    │
 │ idle TTL +    │ │           │ │             │ │                 │
 │ resume inject)│ │           │ │             │ │                 │
 └────┬──────────┘ └────┬──────┘ └──────┬──────┘ └──────────┬──────┘
      │                 │                │                   │
      │             ┌───▼────────────────▼───────────────────▼──┐
      └────────────►│        OpenViking REST API                │
                    │ /api/v1/search/search                      │
                    │ /api/v1/sessions [+/{id}/{messages,commit}]│
                    │ /api/v1/content/read                      │
                    └─────────────────┬─────────────────────────┘
                                      │
   Codex ◄── stdio MCP proxy ──► /mcp (search, store, read, list,
              (env/ovcli.conf)      grep, glob, forget,
                                  add_resource, health)

The checked-in .mcp.json starts servers/mcp-proxy.mjs with node. The proxy keeps stdout protocol-clean, reads the same credential sources as the hooks, sends auth and identity headers to /mcp, caches the server mcp-session-id, and transparently reinitializes once if the server restarts.

For details on OpenViking's MCP endpoint, tools, and protocol, see the MCP Integration Guide. The tools list and per-tool semantics are documented there once, not duplicated here.

How It Works

See DESIGN.md for the commit decision tree — it's the source of truth for which OpenViking session is sealed by which hook event.

SessionStart commit logic (source=startup|clear, heuristic + idle TTL)

Codex fires SessionStart with one of three source values: startup (fresh process / /new / zouk daemon spawn-without-sessionId), resume (/resume or short reconnect), and clear (/clear — the previous transcript is orphaned and a new session_id is created). resume never commits or sweeps; on startup and clear we run the same active-window heuristic.

hooks.json registers SessionStart with matcher: "clear|startup|resume" so codex's dispatcher invokes the script on all three relevant sources. session-start-commit.mjs gates internally so only startup and clear commit/sweep.

On startup or clear, the script:

1. Counts state files (excluding the new session_id) whose lastUpdatedAt is within OPENVIKING_CODEX_ACTIVE_WINDOW_MS (default 2 min) of "now":
   • 0 active → no-op (no orphan to commit)
   • 1 active → commit it (the just-ended session)
   • ≥2 active → skip; rely on idle TTL (we can't tell which one ended)
2. Idle-TTL sweep at the tail: any state file (regardless of session_id) older than OPENVIKING_CODEX_IDLE_TTL_MS (default 30 min) gets committed and cleared.

On any /commit failure (OV unreachable, non-2xx, timeout) we preserve state (don't clearState) so the next sweep can retry.

On resume, the script skips commit/sweep. If local state has no live ovSessionId, it reads /api/v1/sessions/{cx-session-id}/context and injects the latest committed archive overview. The injected block includes a viking://user/sessions/{cx-session-id}/history/ URI and tells the model to use the OpenViking MCP read/search tools for exact prior commands, file paths, tool outputs, or messages. Set OPENVIKING_RESUME_ARCHIVE_INJECT=0 to disable this.

Auto-recall (every UserPromptSubmit)

auto-recall.mjs reads prompt and session_id from stdin, derives the long-lived OpenViking session id (cx-<safe-session-id>) directly from the Codex session id (no plugin state read, so a corrupt state file can't crash recall), calls /api/v1/search/search with that session_id, ranks results, reads full content for top-ranked leaves, and emits:

{ "hookSpecificOutput": { "hookEventName": "UserPromptSubmit", "additionalContext": "<openviking-context source=\"auto-recall\" format=\"digest\">\nOpenViking memory digest:\n- ...\n</openviking-context>" } }

Codex injects additionalContext into the model turn, so memories arrive without an extra tool call. By default the hook runs a Codex compression pass over recalled candidates before injection, dropping weakly-related memories and preserving only a short digest. If the compressor returns NO_RELEVANT_MEMORY, empty text, or non-digest chatter, the hook emits {} and injects nothing. The whole hook has its own OPENVIKING_RECALL_TIMEOUT_MS deadline (default 120s); the bundled hooks.json gives Codex 130s so the script can return {} before Codex kills it. Digests may keep viking:// source URIs and point the model at the OpenViking MCP read/search tools for details when the inline bullet is intentionally short. The outer <openviking-context ...> wrapper is deterministic, not compressor-generated; capture strips it to distinguish recalled context from the user's prompt. Set OPENVIKING_RECALL_COMPRESS=0 to fall back to deterministic short formatting.

The compressor profile is recreated on every SessionStart and cached under OPENVIKING_CODEX_STATE_DIR so cross-session config changes are picked up but each UserPromptSubmit does not probe models. Default fallback order:

1. configured OPENVIKING_RECALL_COMPRESS_MODEL + OPENVIKING_RECALL_COMPRESS_THINKING
2. gpt-5.3-codex-spark with thinking default
3. gpt-5.5 with thinking low
4. off (deterministic digest, no codex exec compression)

Config knobs:

Stop (turn end → add_message, threshold commit)

auto-capture.mjs derives one long-lived OpenViking session id per Codex session_id as cx-<safe-session-id> and incrementally appends every new user/assistant turn via /api/v1/sessions/{id}/messages. The /messages endpoint auto-creates the session on first append. Per-codex-session state lives at ~/.openviking/codex-plugin-state/<safe-session-id>.json. Capture sanitizes obvious hook noise, metadata wrappers, and plugin-injected <openviking-context ...> blocks before append; tool calls/results are retained as compact [tool-call ...] / [tool-result ...] lines capped by OPENVIKING_CAPTURE_TOOL_MAX_CHARS (default 2000).

After a successful append, Stop reads the session meta and commits when pending_tokens >= OPENVIKING_COMMIT_TOKEN_THRESHOLD (default 20000). Threshold commits pass keep_recent_count=OPENVIKING_COMMIT_KEEP_RECENT_COUNT (default 10) so the newest turns remain live for continuity while older context is archived and extracted. PreCompact still commits everything before compaction.

PreCompact (deterministic commit)

pre-compact-capture.mjs:

1. Catch-up append for any turns Stop hasn't captured yet (race-safe via capturedTurnCount)
2. Commit the long-lived OV session so the extractor runs against the full pre-compact transcript
3. Reset ovSessionId to null so the next Stop re-derives the same cx-<safe-session-id> and appends the post-compact half under that deterministic OV session id

Known gap: SIGTERM / Ctrl+C / /exit are silent

Codex fires no hook on process exit. /compact is the only fully-deterministic "context disappearing" signal. If you /exit without /compact, the OV session for that codex session_id stays open. Two fallbacks recover the orphan:

1. The idle-TTL sweep at the next SessionStart commits any state file older than 30 min
2. The active-window heuristic catches it if you /new or /clear shortly after

Codex hook output schema

Codex's hook output schema differs from Claude Code's. Notably:

Unlike Claude Code, Codex does not support decision: "approve"; only decision: "block". A no-op is {} (which is what these scripts emit when there's nothing to add).

Plugin Structure

codex-memory-plugin/
├── .codex-plugin/
│   └── plugin.json              # Plugin manifest (hooks + mcp wiring)
├── hooks/
│   └── hooks.json               # SessionStart + UserPromptSubmit + Stop + PreCompact
│                                  (uses Codex's native ${PLUGIN_ROOT} token; no
│                                   rendering needed on modern Codex)
├── scripts/
│   ├── config.mjs               # Shared config loader (ovcli.conf + env)
│   ├── capture-utils.mjs        # Transcript text extraction, filtering, tool compression
│   ├── debug-log.mjs            # Structured JSONL logger
│   ├── recall-compressor-profile.mjs # Compressor profile detection/cache
│   ├── session-state.mjs        # Per-codex-session OV session state
│   ├── auto-recall.mjs          # UserPromptSubmit hook (REST /search/search)
│   ├── auto-capture.mjs         # Stop hook (append + threshold commit)
│   ├── session-start-commit.mjs # SessionStart hook (active-window + idle TTL)
│   └── pre-compact-capture.mjs  # PreCompact hook
├── servers/
│   ├── mcp-proxy.mjs            # stdio -> OpenViking /mcp bridge
│   └── mcp-proxy.test.mjs       # proxy contract tests
├── setup-helper/
│   └── install.sh               # One-line installer
├── .mcp.json                    # stdio MCP wiring
├── DESIGN.md
├── VERIFICATION.md
└── README.md

No src/ or package.json: there is no build step. Hook scripts and the MCP proxy are zero-dep .mjs files running on Codex's bundled Node 22 or a compatible system Node.

The Codex marketplace catalog that exposes this plugin for codex plugin marketplace add lives at the repo root in .agents/plugins/marketplace.json (Codex resolves a marketplace manifest from the source root, not from this subdirectory). The catalog points at ./examples/codex-memory-plugin using a relative source, so the installed plugin follows the same marketplace snapshot/ref that the user added.

Differences from the Claude Code Plugin

License

Apache-2.0 — same as OpenViking.