Discord Rich Presence daemon for Visual Novels on Linux. Detects games launched via Lutris or Steam, looks them up on VNDB, and shows the title, cover art, and total playtime in your Discord status.

Voice channel

User activity

Features

• Detects games from Lutris (exact name from wrapper) and Steam (AppID → ACF → store name)
• Fuzzy title matching against VNDB using trigram similarity + full-width character normalisation
• Fallback: searches the release endpoint and follows the relation back to the parent VN
• Suppresses explicit cover images (sexual ≥ 1.80 or violence ≥ 1.80) — title still shows
• Playtime from Lutris DB (pga.db) or Steam VDF (localconfig.vdf) — no API key needed
• Discord elapsed timer reflects total hours played, not just this session
• Editable cache.csv for aliases, hard-links, and SKIP entries — reloaded live while running
• ignore.txt with exact-match for short entries (< 4 chars) to prevent false positives like sh

How it works

Main loop

Every 5 seconds the daemon runs detection, debounces the result, checks the cache, queries VNDB if needed, and updates Discord.

flowchart LR
    A[Detection\nLutris or Steam] --> B[Debounce\nstable 2 polls]
    B --> C{Cache\nlookup}
    C -- hit + fresh --> E[Discord RPC]
    C -- hit + expired --> D[VNDB search]
    C -- miss --> D
    D --> E

Detection

flowchart TD
    P[Scan /proc every 5s]
    P --> L{lutris-wrapper\nin cmdline?}
    L -- yes --> LN[Game name from\nwrapper args]
    L -- no --> S{SteamAppId\nin environ?}
    S -- yes --> SA[Read appmanifest_ID.acf\nfrom all library paths]
    SA --> SN[Steam store name]
    S -- no --> NONE[Nothing detected]
    LN --> ST[Read starttime\nfrom /proc/pid/stat field 22]
    SN --> ST
    ST --> SORT[Sort candidates\nby starttime ascending]

Lutris passes the game name explicitly as command-line arguments after lutris-wrapper, so the name is always exact. Steam injects SteamAppId as an environment variable into every game process — the daemon reads it from /proc/<pid>/environ, then finds the matching .acf file across all Steam library paths (including custom drives read from libraryfolders.vdf).

After all candidates are collected, the daemon reads field 22 (starttime) from each process’s /proc/<pid>/stat. Candidates are then sorted ascending by starttime, so the process that launched first is always tried first during VNDB resolution. This makes multi-candidate priority deterministic and reproducible across polls.

📝 Note

See the /proc/\[PID\]/stat field reference for a full breakdown of all stat fields.

💡 Tip

Run with --verbose to see candidates list in the debug output:

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[DEBUG] src/main.cpp:73 4 game candidate(s) found: [DEBUG] src/main.cpp:75 [lutris] pid=2037324 name="終ノ空 remake" starttime(clock ticks)=4906595 [DEBUG] src/main.cpp:75 [lutris] pid=2086738 name="X-Plane 12" starttime(clock ticks)=4906701 [DEBUG] src/main.cpp:75 [steam-appid] pid=2037822 name="心象天儀本線 ~Per aspera ad astra~ Demo" starttime(clock ticks)=4906857 [DEBUG] src/main.cpp:75 [lutris] pid=2038526 name="サクラノ詩－櫻の森の上を舞う－" starttime(clock ticks)=4907260

VNDB resolution

flowchart TD
    Q[Search query] --> VN[POST /kana/vn]
    VN --> SIM{Trigram similarity\n≥ 0.35 OR substring match?}
    SIM -- yes --> MATCH[VnInfo returned]
    SIM -- no --> REL[POST /kana/release]
    REL --> FOUND{Release found?}
    FOUND -- yes --> ID[Fetch parent VN\nby exact ID]
    ID --> MATCH
    FOUND -- no --> NOMATCH[No match\nclear presence]

Before the similarity check, full-width ASCII (！２→!2, （→() is normalised to half-width so Japanese game names from Lutris match VNDB’s stored titles. There is also a substring boost — if the query appears inside the returned title, the score is raised to at least 0.6, handling cases where the detected name is a short prefix of a long VNDB title.

Cache TTL

VNDB results are stored persistently in cache.csv. On each cache hit the daemon compares the entry’s cached_at timestamp against VNDB_CACHE_TTL. If the entry is older than the TTL, it is treated as expired and a fresh VNDB query is issued, updating the stored data and timestamp.

flowchart TD
    HIT[Cache hit] --> AGE{age > VNDB_CACHE_TTL?}
    AGE -- no --> USE[Use cached VnInfo]
    AGE -- yes --> REQUERY[Re-query VNDB\nupdate cache.csv]
    REQUERY --> USE

This means ratings, cover images, and release dates in the cache are automatically refreshed over time without any manual intervention. The log line when a re-query fires looks like:

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[INFO] Cache expired for "..."  age=1442min/1440min — re-querying VNDB

Playtime → Discord elapsed timer

flowchart TD
    SRC{Source?}
    SRC -- lutris --> LDB[Lutris DB\npga.db · hours]
    SRC -- steam-appid --> VDF[Steam VDF\nlocalconfig.vdf · minutes]
    LDB --> PT[playtime in seconds]
    VDF --> PT
    PT --> TS[start_ts = now − playtime]
    TS --> DISC[Discord: elapsed timer\ncounts up from start_ts]

Cache file (cache.csv / cache.db)

Located at ~/.config/vn-discord-rpc/cache.csv (default) or cache.db when CACHE_USE_DB = true. Reloaded automatically whenever the file changes on disk.

Examples:

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# Alias — fix wrong or garbled detection
Nice boat!,School Days,,,,,,,,

# Skip — suppress presence for this title
妹ぱらだいす！２,,SKIP,,,,,,,

# Hard-link — bypass VNDB query, point directly to an entry
My VN Title,,v67,,,,,,,

Ignore list (ignore.txt)

Located at ~/.config/vn-discord-rpc/ignore.txt. One entry per line, # for comments. Reloaded automatically while running.

Matching rules:

• Entry < 4 characters: exact match (case-insensitive) — (ie. prevents sh matching Higurashi)
• Entry ≥ 4 characters: case-insensitive substring match

The default file includes common false-positives: Steam runtimes, Proton, Wine helpers, and launchers.

⚠️ Warning

If a title has no VNDB match, the daemon automatically adds it to ignore.txt after the first failed query. It will not be retried on subsequent polls. To force a retry, remove the entry from ignore.txt. To permanently suppress it without querying VNDB at all, add a SKIP entry to cache.csv instead.

Configuration (src/config.hpp)

🚨 Caution

Be caution on changing IMAGE_SEXUAL and IMAGE_VIOLENCE thresholds in src/config.hpp. Those thresholds are set to 1.80 (slightly below VNDB’s Explicit level of 2.00) because VNDB image ratings are user-reported and may be underrated by a small margin — the 0.20 buffer ensures borderline explicit covers are still suppressed. Raising the threshold above 2.00 would cause explicit (pornographic) cover art to appear in your Discord status, visible to everyone on your friends list. Displaying explicit content in Discord Rich Presence may violates Discord’s Terms of Service and may result in a permanent account ban.

Building

📌 Important

Initialise submodules before building — the two header-only dependencies are not downloaded automatically.

1	git submodule update --init --recursive

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cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build

Dependencies

Usage

💡 Tip

Run with --verbose if a title is not being detected or matched — the debug output shows exactly which process was found, what VNDB returned, and the similarity score.

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./vn-discord-rpc            # normal
./vn-discord-rpc --verbose  # debug logging
./vn-discord-rpc --help

Launch a game through Lutris or Steam, and the daemon will detect it automatically. Press Ctrl+C to quit cleanly.

File locations