@@ -16,4 +16,5 @@ pub mod repos;
 pub mod resolve;
 pub mod stars;
 pub mod tasks;
+pub mod visibility;
 pub mod webhooks;
@@ -14,6 +14,7 @@ use crate::cert;
 use crate::error::{AppError, Result};
 use crate::git::{smart_http, store};
 use crate::state::AppState;
+use crate::visibility::{visibility_check, Decision};
 use crate::webhooks;
 
 // ── Request / Response types ───────────────────────────────────────────────
@@ -308,6 +309,7 @@ pub async fn git_info_refs(
     State(state): State<AppState>,
     Path((owner, repo)): Path<(String, String)>,
     Query(query): Query<InfoRefsQuery>,
+    auth: Option<Extension<AuthenticatedDid>>,
 ) -> Result<Response> {
     let name = repo.trim_end_matches(".git");
     tracing::info!(owner = %owner, repo = %name, "info/refs request");
@@ -322,6 +324,20 @@ pub async fn git_info_refs(
         .ok_or_else(|| AppError::BadRequest("missing ?service= parameter".into()))?;
     tracing::debug!(service = %service, repo = %name, "info/refs service");
 
+    // Enforce read (clone/fetch) visibility. The push advertisement
+    // (service=git-receive-pack) is authorized separately on the
+    // git-receive-pack POST, so leave it untouched here.
+    if service == "git-upload-pack" {
+        let rules = state.db.list_visibility_rules(&record.id).await?;
+        let caller = auth.as_ref().map(|e| e.0 .0.as_str());
+        if visibility_check(&rules, record.is_public, &record.owner_did, caller, "/")
+            == Decision::Deny
+        {
+            tracing::debug!(repo = %name, caller = ?caller, "info/refs read denied by visibility");
+            return Err(AppError::RepoNotFound(format!("{owner}/{name}")));
+        }
+    }
+
     // For receive-pack (push), download the latest from Tigris so the client
     // sees the same refs that acquire_write() will operate on.
     let disk_path = if service == "git-receive-pack" {
@@ -352,6 +368,7 @@ pub async fn git_info_refs(
 pub async fn git_upload_pack(
     State(state): State<AppState>,
     Path((owner, repo)): Path<(String, String)>,
+    auth: Option<Extension<AuthenticatedDid>>,
     body: Bytes,
 ) -> Result<Response> {
     let name = repo.trim_end_matches(".git");
@@ -361,6 +378,14 @@ pub async fn git_upload_pack(
         .await?
         .ok_or_else(|| AppError::RepoNotFound(format!("{owner}/{name}")))?;
 
+    let rules = state.db.list_visibility_rules(&record.id).await?;
+    let caller = auth.as_ref().map(|e| e.0 .0.as_str());
+    if visibility_check(&rules, record.is_public, &record.owner_did, caller, "/") == Decision::Deny
+    {
+        tracing::debug!(repo = %name, caller = ?caller, "upload-pack read denied by visibility");
+        return Err(AppError::RepoNotFound(format!("{owner}/{name}")));
+    }
+
     let disk_path = state
         .repo_store
         .acquire(&record.owner_did, &record.name)
 
@@ -0,0 +1,159 @@
+//! Path-scoped visibility management API. Owner-only, mirrors `api/protect.rs`.
+
+use axum::extract::{Extension, Path, State};
+use axum::http::StatusCode;
+use axum::Json;
+use serde::Deserialize;
+
+use crate::auth::AuthenticatedDid;
+use crate::db::VisibilityMode;
+use crate::error::{AppError, Result};
+use crate::state::AppState;
+
+#[derive(Deserialize)]
+pub struct SetVisibilityRequest {
+    pub path_glob: String,
+    /// "a" or "b"; defaults to "b" if absent or unrecognized.
+    #[serde(default)]
+    pub mode: Option<String>,
+    #[serde(default)]
+    pub reader_dids: Vec<String>,
+}
+
+#[derive(Deserialize)]
+pub struct RemoveVisibilityRequest {
+    pub path_glob: String,
+}
+
+fn require_owner(record: &crate::db::RepoRecord, caller: &str) -> Result<()> {
+    let owner_short = record
+        .owner_did
+        .split(':')
+        .next_back()
+        .unwrap_or(&record.owner_did);
+    if caller != record.owner_did && caller != owner_short {
+        return Err(AppError::BadRequest(
+            "only the repo owner can manage visibility".into(),
+        ));
+    }
+    Ok(())
+}
+
+/// PUT /api/v1/repos/{owner}/{repo}/visibility
+pub async fn set_visibility(
+    State(state): State<AppState>,
+    Extension(auth): Extension<AuthenticatedDid>,
+    Path((owner, repo)): Path<(String, String)>,
+    Json(req): Json<SetVisibilityRequest>,
+) -> Result<(StatusCode, Json<serde_json::Value>)> {
+    let record = state
+        .db
+        .get_repo(&owner, &repo)
+        .await?
+        .ok_or_else(|| AppError::RepoNotFound(format!("{owner}/{repo}")))?;
+    require_owner(&record, &auth.0)?;
+
+    let mode = match req.mode.as_deref() {
+        Some("a") => VisibilityMode::A,
+        _ => VisibilityMode::B,
+    };
+
+    // Mode A hides existence and is only coherent for the whole repo; a subtree
+    // cannot hide its existence without rewriting git history (see spec).
+    if mode == VisibilityMode::A && req.path_glob != "/" {
+        return Err(AppError::BadRequest(
+            "mode 'a' (hide) is only allowed for the whole repo (path_glob '/'); use mode 'b' for subtrees".into(),
+        ));
+    }
+
+    // An empty reader_dids list is valid and intentional: the owner is always
+    // allowed by visibility_check, so a "/" rule with no readers is exactly the
+    // whole-repo "private to owner only" case.
+    state
+        .db
+        .set_visibility_rule(&record.id, &req.path_glob, mode, &req.reader_dids, &auth.0)
+        .await?;
+
+    let subtree_warning = req.path_glob != "/";
+    tracing::info!(
+        repo = %repo, caller = %auth.0, path_glob = %req.path_glob, mode = %mode.as_str(),
+        subtree_pending = subtree_warning,
+        "visibility rule set"
+    );
+
+    Ok((
+        StatusCode::CREATED,
+        Json(serde_json::json!({
+            "status": "set",
+            "repo": format!("{owner}/{repo}"),
+            "path_glob": req.path_glob,
+            "mode": mode.as_str(),
+            "reader_dids": req.reader_dids,
+            "subtree_clone_enforcement_pending": subtree_warning,
+        })),
+    ))
+}
+
+/// DELETE /api/v1/repos/{owner}/{repo}/visibility
+pub async fn remove_visibility(
+    State(state): State<AppState>,
+    Extension(auth): Extension<AuthenticatedDid>,
+    Path((owner, repo)): Path<(String, String)>,
+    Json(req): Json<RemoveVisibilityRequest>,
+) -> Result<Json<serde_json::Value>> {
+    let record = state
+        .db
+        .get_repo(&owner, &repo)
+        .await?
+        .ok_or_else(|| AppError::RepoNotFound(format!("{owner}/{repo}")))?;
+    require_owner(&record, &auth.0)?;
+
+    state
+        .db
+        .remove_visibility_rule(&record.id, &req.path_glob)
+        .await?;
+
+    tracing::info!(
+        repo = %repo, caller = %auth.0, path_glob = %req.path_glob,
+        "visibility rule removed"
+    );
+
+    Ok(Json(serde_json::json!({
+        "status": "removed",
+        "repo": format!("{owner}/{repo}"),
+        "path_glob": req.path_glob,
+    })))
+}
+
+/// GET /api/v1/repos/{owner}/{repo}/visibility
+pub async fn list_visibility(
+    State(state): State<AppState>,
+    Extension(auth): Extension<AuthenticatedDid>,
+    Path((owner, repo)): Path<(String, String)>,
+) -> Result<Json<serde_json::Value>> {
+    let record = state
+        .db
+        .get_repo(&owner, &repo)
+        .await?
+        .ok_or_else(|| AppError::RepoNotFound(format!("{owner}/{repo}")))?;
+    require_owner(&record, &auth.0)?;
+
+    let rules = state.db.list_visibility_rules(&record.id).await?;
+    let rules_json: Vec<_> = rules
+        .into_iter()
+        .map(|r| {
+            serde_json::json!({
+                "path_glob": r.path_glob,
+                "mode": r.mode.as_str(),
+                "reader_dids": r.reader_dids,
+                "created_by": r.created_by,
+            })
+        })
+        .collect();
+
+    Ok(Json(serde_json::json!({
+        "repo": format!("{owner}/{repo}"),
+        "count": rules_json.len(),
+        "rules": rules_json,
+    })))
+}
@@ -21,6 +21,51 @@ pub struct RepoRecord {
     pub machine_id: Option<String>,
 }
 
+/// Per-rule replication mode for a visibility rule.
+/// `A` hides existence entirely (only valid at whole-repo scope `/`).
+/// `B` keeps object SHAs and the path visible but withholds content
+/// (the only mode allowed for subtrees; enforced on clones in Phase 3).
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "lowercase")]
+pub enum VisibilityMode {
+    A,
+    B,
+}
+
+impl VisibilityMode {
+    pub fn as_str(&self) -> &'static str {
+        match self {
+            VisibilityMode::A => "a",
+            VisibilityMode::B => "b",
+        }
+    }
+
+    pub fn from_db(s: &str) -> Self {
+        match s {
+            "a" => VisibilityMode::A,
+            "b" => VisibilityMode::B,
+            other => {
+                tracing::warn!("unknown visibility mode in DB: {other:?}, defaulting to B");
+                VisibilityMode::B
+            }
+        }
+    }
+}
+
+/// A path-scoped visibility rule. `path_glob` is "/" for whole-repo, or a
+/// subtree pattern such as "/secret-pkg/**". The repo owner is always an
+/// implicit reader regardless of `reader_dids`.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct VisibilityRule {
+    pub id: String,
+    pub repo_id: String,
+    pub path_glob: String,
+    pub mode: VisibilityMode,
+    pub reader_dids: Vec<String>,
+    pub created_by: String,
+    pub created_at: DateTime<Utc>,
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct PullRequest {
     pub id: String,
@@ -378,6 +423,18 @@ impl Db {
                 UNIQUE(repo_id, branch)
             )"#,
             "CREATE INDEX IF NOT EXISTS idx_protected_branches_repo ON protected_branches(repo_id)",
+            // ── Path-scoped visibility ────────────────────────────────────────
+            r#"CREATE TABLE IF NOT EXISTS visibility_rules (
+                id          TEXT NOT NULL PRIMARY KEY,
+                repo_id     TEXT NOT NULL,
+                path_glob   TEXT NOT NULL,
+                mode        TEXT NOT NULL,
+                reader_dids TEXT NOT NULL,
+                created_by  TEXT NOT NULL,
+                created_at  TEXT NOT NULL,
+                UNIQUE(repo_id, path_glob)
+            )"#,
+            "CREATE INDEX IF NOT EXISTS idx_visibility_rules_repo ON visibility_rules(repo_id)",
             // ── Repo stars ──────────────────────────────────────────────────
             r#"CREATE TABLE IF NOT EXISTS repo_stars (
                 id         TEXT NOT NULL PRIMARY KEY,
@@ -1874,6 +1931,80 @@ impl Db {
     }
 }
 
+// ── Path-scoped Visibility ────────────────────────────────────────────────────
+
+impl Db {
+    pub async fn set_visibility_rule(
+        &self,
+        repo_id: &str,
+        path_glob: &str,
+        mode: VisibilityMode,
+        reader_dids: &[String],
+        created_by: &str,
+    ) -> Result<()> {
+        let id = Uuid::new_v4().to_string();
+        let now = Utc::now().to_rfc3339();
+        let readers = serde_json::to_string(reader_dids).unwrap_or_else(|_| "[]".to_string());
+        sqlx::query(
+            "INSERT INTO visibility_rules
+                 (id, repo_id, path_glob, mode, reader_dids, created_by, created_at)
+             VALUES ($1, $2, $3, $4, $5, $6, $7)
+             ON CONFLICT (repo_id, path_glob) DO UPDATE
+             SET mode = EXCLUDED.mode,
+                 reader_dids = EXCLUDED.reader_dids,
+                 created_by = EXCLUDED.created_by,
+                 created_at = EXCLUDED.created_at",
+        )
+        .bind(&id)
+        .bind(repo_id)
+        .bind(path_glob)
+        .bind(mode.as_str())
+        .bind(&readers)
+        .bind(created_by)
+        .bind(&now)
+        .execute(&self.pool)
+        .await?;
+        Ok(())
+    }
+
+    pub async fn remove_visibility_rule(&self, repo_id: &str, path_glob: &str) -> Result<()> {
+        sqlx::query("DELETE FROM visibility_rules WHERE repo_id = $1 AND path_glob = $2")
+            .bind(repo_id)
+            .bind(path_glob)
+            .execute(&self.pool)
+            .await?;
+        Ok(())
+    }
+
+    pub async fn list_visibility_rules(&self, repo_id: &str) -> Result<Vec<VisibilityRule>> {
+        let rows = sqlx::query(
+            "SELECT id, repo_id, path_glob, mode, reader_dids, created_by, created_at
+             FROM visibility_rules WHERE repo_id = $1 ORDER BY path_glob",
+        )
+        .bind(repo_id)
+        .fetch_all(&self.pool)
+        .await?;
+        Ok(rows
+            .into_iter()
+            .map(|r| {
+                let readers: String = r.get("reader_dids");
+                let created_at: String = r.get("created_at");
+                VisibilityRule {
+                    id: r.get("id"),
+                    repo_id: r.get("repo_id"),
+                    path_glob: r.get("path_glob"),
+                    mode: VisibilityMode::from_db(&r.get::<String, _>("mode")),
+                    reader_dids: serde_json::from_str(&readers).unwrap_or_default(),
+                    created_by: r.get("created_by"),
+                    created_at: created_at
+                        .parse::<DateTime<Utc>>()
+                        .unwrap_or_else(|_| Utc::now()),
+                }
+            })
+            .collect())
+    }
+}
+
 // ── Repo Stars ────────────────────────────────────────────────────────────────
 
 impl Db {
 
@@ -16,6 +16,7 @@ mod rate_limit;
 mod server;
 mod state;
 mod sync;
+mod visibility;
 mod webhooks;
 
 use anyhow::{Context, Result};