diff --git a/crates/dry_run_cli/src/main.rs b/crates/dry_run_cli/src/main.rs
index 8020d12..32f0ecb 100644
--- a/crates/dry_run_cli/src/main.rs
+++ b/crates/dry_run_cli/src/main.rs
@@ -966,14 +966,8 @@ fn write_snapshot_export(
     key: &SnapshotKey,
     snap: &dry_run_core::SchemaSnapshot,
 ) -> anyhow::Result<PathBuf> {
-    let path = out_root
-        .join(&key.project_id.0)
-        .join(&key.database_id.0)
-        .join(format!(
-            "{}-{}.json.zst",
-            snap.timestamp.format("%Y%m%dT%H%M%SZ"),
-            snap.content_hash,
-        ));
+    let path =
+        dry_run_core::history::snapshot_path(out_root, key, snap.timestamp, &snap.content_hash);
     if let Some(parent) = path.parent() {
         std::fs::create_dir_all(parent)?;
     }
diff --git a/crates/dry_run_core/src/history/filesystem_layout.rs b/crates/dry_run_core/src/history/filesystem_layout.rs
new file mode 100644
index 0000000..94aa367
--- /dev/null
+++ b/crates/dry_run_core/src/history/filesystem_layout.rs
@@ -0,0 +1,34 @@
+use crate::history::SnapshotKey;
+use chrono::{DateTime, NaiveDateTime, TimeZone, Utc};
+use std::path::{Path, PathBuf};
+
+pub const SNAPSHOT_EXTENSION: &str = "json.zst";
+
+const TS_FORMAT: &str = "%Y%m%dT%H%M%SZ";
+
+#[must_use]
+pub fn snapshot_path(
+    root: &Path,
+    key: &SnapshotKey,
+    timestamp: DateTime<Utc>,
+    content_hash: &str,
+) -> PathBuf {
+    root.join(&key.project_id.0)
+        .join(&key.database_id.0)
+        .join(format!(
+            "{}-{}.{}",
+            timestamp.format(TS_FORMAT),
+            content_hash,
+            SNAPSHOT_EXTENSION,
+        ))
+}
+
+#[must_use]
+pub fn parse_snapshot_filename(name: &str) -> Option<(DateTime<Utc>, String)> {
+    let stem = name.strip_suffix(&format!(".{SNAPSHOT_EXTENSION}"))?;
+    let (ts_str, hash) = stem.split_once('-')?;
+    let naive = NaiveDateTime::parse_from_str(ts_str, TS_FORMAT).ok()?;
+    let ts = Utc.from_utc_datetime(&naive);
+
+    Some((ts, hash.to_string()))
+}
diff --git a/crates/dry_run_core/src/history/filesystem_store.rs b/crates/dry_run_core/src/history/filesystem_store.rs
new file mode 100644
index 0000000..523a9cb
--- /dev/null
+++ b/crates/dry_run_core/src/history/filesystem_store.rs
@@ -0,0 +1,242 @@
+use std::path::{Path, PathBuf};
+use std::sync::Arc;
+
+use async_trait::async_trait;
+use chrono::{DateTime, Utc};
+use tracing::{debug, info};
+
+use crate::error::{Error, Result};
+use crate::history::{
+    DatabaseId, ProjectId, PutOutcome, SnapshotKey, SnapshotRef, SnapshotStore, SnapshotSummary,
+    TimeRange, parse_snapshot_filename, snapshot_path,
+};
+use crate::schema::SchemaSnapshot;
+
+pub struct FilesystemStore {
+    root: Arc<PathBuf>,
+}
+
+impl FilesystemStore {
+    pub fn new(root: impl Into<PathBuf>) -> Self {
+        Self {
+            root: Arc::new(root.into()),
+        }
+    }
+
+    pub fn list_keys(&self) -> Result<Vec<SnapshotKey>> {
+        list_keys_sync(&self.root)
+    }
+}
+
+#[async_trait]
+impl SnapshotStore for FilesystemStore {
+    async fn put(&self, key: &SnapshotKey, snap: &SchemaSnapshot) -> Result<PutOutcome> {
+        let root = self.root.clone();
+        let key = key.clone();
+        let snap = snap.clone();
+        run_blocking(move || {
+            let stream_dir = stream_dir(&root, &key);
+            if let Some(latest) = read_latest_hash(&stream_dir)?
+                && latest == snap.content_hash
+            {
+                debug!(hash = %snap.content_hash, "schema unchanged, skipping put");
+                return Ok(PutOutcome::Deduped);
+            }
+
+            let path = snapshot_path(&root, &key, snap.timestamp, &snap.content_hash);
+            if let Some(parent) = path.parent() {
+                std::fs::create_dir_all(parent).map_err(|e| {
+                    Error::History(format!("create_dir_all {}: {e}", parent.display()))
+                })?;
+            }
+
+            // atomic write: tmp + rename
+            let tmp = path.with_extension("zst.tmp");
+            let json = serde_json::to_vec(&snap)
+                .map_err(|e| Error::History(format!("cannot serialize snapshot: {e}")))?;
+            let compressed = zstd::encode_all(json.as_slice(), 3)
+                .map_err(|e| Error::History(format!("zstd encode: {e}")))?;
+            std::fs::write(&tmp, compressed)
+                .map_err(|e| Error::History(format!("write {}: {e}", tmp.display())))?;
+            std::fs::rename(&tmp, &path)
+                .map_err(|e| Error::History(format!("rename to {}: {e}", path.display())))?;
+
+            info!(
+                hash = %snap.content_hash,
+                project = %key.project_id.0,
+                database = %key.database_id.0,
+                "snapshot put (fs)",
+            );
+            Ok(PutOutcome::Inserted)
+        })
+        .await
+    }
+
+    async fn get(&self, key: &SnapshotKey, at: SnapshotRef) -> Result<SchemaSnapshot> {
+        let root = self.root.clone();
+        let key = key.clone();
+        run_blocking(move || {
+            let entries = read_stream_entries(&stream_dir(&root, &key))?;
+
+            let chosen = match &at {
+                SnapshotRef::Latest => entries.into_iter().max_by_key(|(ts, _, _)| *ts),
+                SnapshotRef::At(target) => entries
+                    .into_iter()
+                    .filter(|(ts, _, _)| *ts <= *target)
+                    .max_by_key(|(ts, _, _)| *ts),
+                SnapshotRef::Hash(h) => entries.into_iter().find(|(_, hash, _)| hash == h),
+            };
+
+            let (_, _, path) = chosen.ok_or_else(|| {
+                let detail = match &at {
+                    SnapshotRef::Latest => "latest".to_string(),
+                    SnapshotRef::At(ts) => format!("at-or-before {ts}"),
+                    SnapshotRef::Hash(h) => format!("hash {h}"),
+                };
+                Error::History(format!("snapshot not found ({detail})"))
+            })?;
+
+            let bytes = std::fs::read(&path)
+                .map_err(|e| Error::History(format!("read {}: {e}", path.display())))?;
+            let json = zstd::decode_all(bytes.as_slice())
+                .map_err(|e| Error::History(format!("zstd decode: {e}")))?;
+            serde_json::from_slice(&json)
+                .map_err(|e| Error::History(format!("corrupt snapshot JSON: {e}")))
+        })
+        .await
+    }
+
+    async fn list(&self, key: &SnapshotKey, range: TimeRange) -> Result<Vec<SnapshotSummary>> {
+        let root = self.root.clone();
+        let key = key.clone();
+        run_blocking(move || {
+            let entries = read_stream_entries(&stream_dir(&root, &key))?;
+            let mut summaries: Vec<SnapshotSummary> = entries
+                .into_iter()
+                .filter(|(ts, _, _)| {
+                    range.from.is_none_or(|from| *ts >= from) && range.to.is_none_or(|to| *ts < to)
+                })
+                .map(|(ts, hash, _)| SnapshotSummary {
+                    id: 0,
+                    timestamp: ts,
+                    content_hash: hash,
+                    database: key.database_id.0.clone(),
+                    project_id: Some(key.project_id.0.clone()),
+                    database_id: Some(key.database_id.0.clone()),
+                })
+                .collect();
+            summaries.sort_by_key(|s| std::cmp::Reverse(s.timestamp));
+            Ok(summaries)
+        })
+        .await
+    }
+
+    async fn latest(&self, key: &SnapshotKey) -> Result<Option<SnapshotSummary>> {
+        Ok(self
+            .list(key, TimeRange::default())
+            .await?
+            .into_iter()
+            .next())
+    }
+
+    async fn delete_before(&self, key: &SnapshotKey, cutoff: DateTime<Utc>) -> Result<usize> {
+        let root = self.root.clone();
+        let key = key.clone();
+        run_blocking(move || {
+            let entries = read_stream_entries(&stream_dir(&root, &key))?;
+            let mut deleted = 0usize;
+            for (ts, _, path) in entries {
+                if ts < cutoff {
+                    std::fs::remove_file(&path)
+                        .map_err(|e| Error::History(format!("remove {}: {e}", path.display())))?;
+                    deleted += 1;
+                }
+            }
+            Ok(deleted)
+        })
+        .await
+    }
+}
+
+fn stream_dir(root: &Path, key: &SnapshotKey) -> PathBuf {
+    root.join(&key.project_id.0).join(&key.database_id.0)
+}
+
+fn read_stream_entries(dir: &Path) -> Result<Vec<(DateTime<Utc>, String, PathBuf)>> {
+    if !dir.is_dir() {
+        return Ok(Vec::new());
+    }
+    let mut entries = Vec::new();
+    for entry in std::fs::read_dir(dir)
+        .map_err(|e| Error::History(format!("read_dir {}: {e}", dir.display())))?
+    {
+        let entry = entry.map_err(|e| Error::History(format!("dirent: {e}")))?;
+        let path = entry.path();
+        let Some(name) = path.file_name().and_then(|n| n.to_str()) else {
+            continue;
+        };
+        if let Some((ts, hash)) = parse_snapshot_filename(name) {
+            entries.push((ts, hash, path));
+        }
+    }
+    Ok(entries)
+}
+
+fn read_latest_hash(dir: &Path) -> Result<Option<String>> {
+    Ok(read_stream_entries(dir)?
+        .into_iter()
+        .max_by_key(|(ts, _, _)| *ts)
+        .map(|(_, hash, _)| hash))
+}
+
+fn list_keys_sync(root: &Path) -> Result<Vec<SnapshotKey>> {
+    let mut keys = Vec::new();
+    if !root.is_dir() {
+        return Ok(keys);
+    }
+    for proj_entry in std::fs::read_dir(root)
+        .map_err(|e| Error::History(format!("read_dir {}: {e}", root.display())))?
+    {
+        let proj_entry = proj_entry.map_err(|e| Error::History(format!("dirent: {e}")))?;
+        let proj_path = proj_entry.path();
+        if !proj_path.is_dir() {
+            continue;
+        }
+        let Some(project_id) = proj_path.file_name().and_then(|n| n.to_str()) else {
+            continue;
+        };
+        for db_entry in std::fs::read_dir(&proj_path)
+            .map_err(|e| Error::History(format!("read_dir {}: {e}", proj_path.display())))?
+        {
+            let db_entry = db_entry.map_err(|e| Error::History(format!("dirent: {e}")))?;
+            let db_path = db_entry.path();
+            if !db_path.is_dir() {
+                continue;
+            }
+            let Some(database_id) = db_path.file_name().and_then(|n| n.to_str()) else {
+                continue;
+            };
+            keys.push(SnapshotKey {
+                project_id: ProjectId(project_id.to_string()),
+                database_id: DatabaseId(database_id.to_string()),
+            });
+        }
+    }
+    keys.sort_by(|a, b| {
+        a.project_id
+            .0
+            .cmp(&b.project_id.0)
+            .then_with(|| a.database_id.0.cmp(&b.database_id.0))
+    });
+    Ok(keys)
+}
+
+async fn run_blocking<F, T>(f: F) -> Result<T>
+where
+    F: FnOnce() -> Result<T> + Send + 'static,
+    T: Send + 'static,
+{
+    tokio::task::spawn_blocking(f)
+        .await
+        .map_err(|e| Error::History(format!("blocking task failed: {e}")))?
+}
diff --git a/crates/dry_run_core/src/history/mod.rs b/crates/dry_run_core/src/history/mod.rs
index b37282b..202a516 100644
--- a/crates/dry_run_core/src/history/mod.rs
+++ b/crates/dry_run_core/src/history/mod.rs
@@ -1,6 +1,10 @@
+pub mod filesystem_layout;
+mod filesystem_store;
 mod snapshot_store;
 mod store;
 
+pub use filesystem_layout::{SNAPSHOT_EXTENSION, parse_snapshot_filename, snapshot_path};
+pub use filesystem_store::FilesystemStore;
 pub use snapshot_store::{
     DatabaseId, ProjectId, PutOutcome, SnapshotKey, SnapshotRef, SnapshotStore, TimeRange,
 };