diff --git a/storage/experiments_schema.sql b/storage/experiments_schema.sql
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+++ b/storage/experiments_schema.sql
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+-- Experiment OS schema (plan 006) — pre-registered, auto-adjudicated
+-- counterfactual experiments over logged fires.
+--
+-- Applied by research/experiments/registry.apply_schema on first run (same
+-- idiom as pg_schema.sql; also handed to the owner to run manually if preferred).
+-- Idempotent: safe to run repeatedly (CREATE ... IF NOT EXISTS throughout).
+
+-- An experiment is a pre-registered, immutable contract. Rows are never
+-- updated after registration except status/verdict fields.
+CREATE TABLE IF NOT EXISTS experiments (
+    id            TEXT PRIMARY KEY,          -- slug, e.g. 'time_stop_10m_v1'
+    registered_at TIMESTAMP NOT NULL,
+    hypothesis    TEXT NOT NULL,             -- one sentence, human-readable
+    population    JSONB NOT NULL,            -- PopulationConfig dump + extra filters
+    intervention  JSONB NOT NULL,            -- typed params, e.g. {"kind":"time_stop","minutes":10,"confirm":"new_high_or_0.5R"}
+    bars          JSONB NOT NULL,            -- pre-registered pass/fail criteria, e.g. {"expR_delta_min":0.05,"min_n":300,"p_max":0.05}
+    futility      JSONB,                     -- early-kill rule, e.g. {"min_n":500,"expR_delta_max":-0.02}
+    fidelity      JSONB NOT NULL,            -- slippage floors: {"atr_frac":0.25,"spread_mult":3,"adverse_ticks":1}
+    status        TEXT NOT NULL DEFAULT 'running',  -- running|passed|failed|inconclusive|killed
+    verdict_at    TIMESTAMP,
+    verdict_note  TEXT
+);
+
+-- One row per (experiment, replayed fire): the counterfactual outcome.
+CREATE TABLE IF NOT EXISTS experiment_runs (
+    experiment_id TEXT NOT NULL REFERENCES experiments(id),
+    fire_id       TEXT NOT NULL,             -- order_id / receipt correlation id
+    symbol        TEXT NOT NULL,
+    session_date  DATE NOT NULL,
+    baseline_r    DOUBLE PRECISION,          -- what actually happened (R units)
+    variant_r     DOUBLE PRECISION,          -- counterfactual outcome (R units)
+    detail        JSONB,                     -- entry/exit stamps, fills, floor hits
+    computed_at   TIMESTAMP NOT NULL,
+    PRIMARY KEY (experiment_id, fire_id)
+);
+CREATE INDEX IF NOT EXISTS idx_exp_runs_exp_date ON experiment_runs (experiment_id, session_date);
+
+-- Verdict history (append-only; the dashboard ledger reads this).
+CREATE TABLE IF NOT EXISTS experiment_verdicts (
+    experiment_id TEXT NOT NULL REFERENCES experiments(id),
+    as_of         TIMESTAMP NOT NULL,
+    n             INTEGER NOT NULL,
+    metrics       JSONB NOT NULL,            -- observed values vs each bar
+    verdict       TEXT NOT NULL,             -- PASS|FAIL|INCONCLUSIVE|KILLED
+    PRIMARY KEY (experiment_id, as_of)
+);