Decode replay ground truth (replay_mine oracle)

The authoritative answer to "what actually happened in this episode" comes from re-simulating the recorded replay, not from telemetry. replay_mine.nim loads the recorded .bitreplay(.z) / .z replay, decompresses it (zippy), rebuilds the game config, and replays the recorded inputs tick-by-tick through a real initSimServer. Because roles and deaths are input + seed driven, the reconstruction reproduces them exactly — that is why it is an oracle and not an estimate.

Do NOT infer death / survival / movement from:

• live telemetry (player artifacts, notsus traces),
• the crewborg trace.db matched observer (its game_over.alive_by_color is UNRELIABLE — the trace ends mid-meeting and mismatched authoritative kills in 36–53 of 60 episodes), or
• server results.json (a matched observer; fine for scores/win/kills per seat, but the per-slot diedTick/dist oracle lives only here).

The tool in this package is universal/tools/replay_mine.nim (see its .note.md). It is the canonical copy of the _crewrift-0136 branch oracle. It imports ./replays and ./sim relatively, so it must be built inside a live crewrift repo checkout, not in this package.

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Step 1 — get the replay URL for the episode

Replays are public S3 objects, zlib/zippy-compressed.

• Known job_id (from a memory note or a prior run): the URL pattern is

  https://softmax-public.s3.amazonaws.com/replays/{job_id}.z
  

• From an experience-request: GET {server}/v2/experience-requests/{xid} → each episodes[] entry carries id (ereq_…), job_id, participants[], and a ready-to-use replay_url (the public S3 URL). Use replay_url directly.

Important: only experience-request episodes return a downloadable replay_url. League-round (non-experience-request) replays are NOT available via API (/v2/episode-requests 404s) — those are watchable only in the softmax.com Observatory web UI. So always confirm cruxes via experience-request episodes, which DO return a replay you can decode here.

Download it:

curl -fSL "https://softmax-public.s3.amazonaws.com/replays/{job_id}.z" -o /tmp/ep.z
# or, from an xreq detail:
curl -fSL "<replay_url from episodes[].replay_url>" -o /tmp/ep.z

Tip: the artifact-harvesting launcher universal/tools/antfarm_run.py saves replay + results + logs per episode into episode_NN/ folders, so if you already ran it the .z is on disk. (NOTE: that launcher is SUPERSEDED — it emits the pre-rework xreq body and 422s until patched to the unified roster shape per the crewrift-xreq-roster-api-change memory note. If you only need the replay URL, hit GET /v2/experience-requests/{xid} directly instead.)

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Step 2 — build replay_mine inside the live crewrift repo

replay_mine.nim imports ./replays and ./sim, so build it where those sibling modules and the data/ dir live — the crewrift repo's src/crewrift/.

# Copy this package's canonical copy into the live repo's src dir, then build:
cp /Users/daveey/packages/crewrift-player-optimization/universal/tools/replay_mine.nim \
   <CREWRIFT_REPO>/src/crewrift/replay_mine.nim
cd <CREWRIFT_REPO>
nim c -d:release src/crewrift/replay_mine.nim

<CREWRIFT_REPO> is the live crewrift checkout. (session-derived, unverified) In recent sessions that checkout was the _crewrift-0136 branch dir, e.g. ~/code/crewrift/_crewrift-0136; confirm the actual path before building. If the repo already has its own src/crewrift/replay_mine.nim, build that one — it's the same oracle.

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Step 3 — run it against the replay

Run with cwd = the crewrift repo so it finds data/.

cd <CREWRIFT_REPO>
./src/crewrift/replay_mine /tmp/ep.z /tmp/ep.csv 2>/dev/null

• Arg 1 = the replay file (.bitreplay, .bitreplay.z, or the .z from S3).
• Arg 2 (optional) = output CSV path. Always pass it when scripting — with an out path it writes a CLEAN CSV to that file, kept separate from the sim's stdout noise. With NO second arg it writes the CSV to stderr (and stdout still carries sim noise), so a no-arg run is for eyeballing, not parsing.
• 2>/dev/null drops the sim's stderr noise. The tool also prints a full kill / vote / meeting log to stdout during the replay — keep stdout if you want that event log; redirect or ignore it if you only want the CSV.

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Output CSV schema

One row per slot, exactly config.minPlayers rows (the seated players):

slot,role,reward,tasks,alive,diedTick,dist

column	meaning
slot	0-based player index — matches the seat order you passed images / roster entries to run-episode.
role	crew / imposter, seed-deterministic.
reward	final per-player score (the leaderboard input).
tasks	tasks rewarded. (May diverge harmlessly from the live run — see gotchas.)
alive	survived to end (true/false).
diedTick	-1 = survived, otherwise the integer tick of death.
dist	total Manhattan distance traveled (accumulated per tick from position deltas) — a movement / activity / positioning proxy.

diedTick + dist are exactly what the crewrift-perception-presence-not-recall and crewrift-leaderboard-gap-diagnosis notes mean by "replay-decoded": presence-at-kill, isolation, and victim-link diagnoses all ground out in these columns.

To find YOUR tested policy's row: the slot is the seat you placed it in. To cross-check against results.json (GET {server}/observatory/jobs/{job_id}/artifacts/results, whose length-8 arrays are slot-indexed, slot i = seat i), match your policy_version_id against participants[].position / participants[].policy_version_id from the xreq detail to recover the seat index.

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Gotchas

• Build location is load-bearing. replay_mine.nim uses relative imports (./replays, ./sim) and the sim needs data/. Build it inside the crewrift repo's src/crewrift/ and run with cwd = that repo. Building it standalone in this package fails to resolve imports.
• diedTick -1 means SURVIVED, not "died at tick -1". Filter diedTick >= 0 for actual deaths.
• tasks / reward may diverge harmlessly from the live run (the tool's own header flags this). role, alive, and diedTick are seed/input-exact and are what you trust for who-died / who-survived. Use reward for relative scoring, not as a byte-exact match to the live leaderboard.
• No second arg → CSV on stderr. If you forget the out-path and parse stdout, you'll parse sim noise. Always pass out.csv when scripting.
• Wrong S3 path 403/404s. The bucket is softmax-public, prefix replays/, suffix .z. League-round replays simply don't exist at that route — use an experience-request episode's replay_url.
• Slots vs. colors. This CSV is slot-indexed (seat order). The crewborg trace resolves color↔role but is a different (and for who-died, unreliable) observer — don't cross slots and colors without the role_resolved mapping.
• A sibling replay_ambush.nim / replay_pos.nim exists for other extractions (kill-log, per-tick x/y/alive/role for all 8 slots at any sample rate). This replay_mine emits the compact diedTick/dist/role/reward CSV — pick the tool that emits the column you need rather than assuming one binary has everything. The position variant is built the same way (import ./sim, ./replays; dump per-tick tracks).

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Success check

You have the oracle output when:

1. /tmp/ep.csv exists and its header is exactly slot,role,reward,tasks,alive,diedTick,dist.
2. It has config.minPlayers data rows (typically the seated count, e.g. 8).
3. role values are crew/imposter and the imposter count is plausible (not all-crew).
4. diedTick is -1 for survivors and a positive tick for the dead, and the count of diedTick >= 0 rows matches the kill/vote log the tool printed to stdout.

If role is empty, all rows show diedTick = -1 on a known-lethal game, or the run errored on a missing data/ path, you built/ran outside the crewrift repo — redo Step 2 with cwd = the live repo. If the download 403/404s, you used a league-round job_id or the wrong S3 prefix — re-fetch replay_url from an experience-request episode.