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diff --git a/src/git/sync.rs b/src/git/sync.rs
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+++ b/src/git/sync.rs
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+//! Git Data Synchronization Across Owner Repositories
+//!
+//! This module provides functions to sync git data across multiple owner repositories
+//! that are authorized by the same state event. This is used when:
+//!
+//! 1. A push is received that satisfies a state event - the git data needs to be
+//!    copied to other owner repos that authorize the same state
+//! 2. Purgatory sync fetches git data from remote - needs to distribute to all
+//!    authorized owner repos
+//!
+//! ## Architecture
+//!
+//! The key insight is that multiple owners can have announcements for the same
+//! repository identifier, and they may share maintainers. When a state event
+//! authorizes a push, that push should be reflected in ALL owner repositories
+//! that would authorize the same state.
+
+use std::collections::HashMap;
+use std::path::Path;
+use std::process::Command;
+use tracing::{debug, info, warn};
+
+use crate::git::{self, oid_exists};
+use crate::git::authorization::{collect_authorized_maintainers, RepositoryData};
+use crate::nostr::events::RepositoryState;
+
+/// Result of syncing git data to owner repositories
+#[derive(Debug, Default)]
+pub struct SyncResult {
+    /// Number of repositories synced
+    pub repos_synced: usize,
+    /// Number of refs created across all repos
+    pub refs_created: usize,
+    /// Number of refs updated across all repos
+    pub refs_updated: usize,
+    /// Number of refs deleted across all repos
+    pub refs_deleted: usize,
+    /// Number of repositories where HEAD was set
+    pub heads_set: usize,
+    /// Errors encountered (repo path -> error message)
+    pub errors: Vec<(String, String)>,
+}
+
+/// Result of aligning a single repository with state
+#[derive(Debug, Default)]
+pub struct AlignmentResult {
+    /// Number of refs created
+    pub refs_created: usize,
+    /// Number of refs updated
+    pub refs_updated: usize,
+    /// Number of refs deleted
+    pub refs_deleted: usize,
+    /// Whether HEAD was set
+    pub head_set: bool,
+}
+
+/// Sync git data from a source repository to all other owner repositories
+/// that authorize the given state event.
+///
+/// This function:
+/// 1. Collects all authorized maintainers per owner from announcements
+/// 2. For each owner whose maintainer set authorizes the state author:
+///    - Skips if a newer state already exists for that owner
+///    - Copies missing OIDs from source repo to target repo
+///    - Aligns refs with the state
+///
+/// # Arguments
+/// * `source_repo_path` - Path to the repository that has the git data
+/// * `state` - The repository state event that authorized the push
+/// * `db_repo_data` - Repository data from database (announcements + states)
+/// * `git_data_path` - Base path for git repositories
+///
+/// # Returns
+/// A `SyncResult` with statistics about what was synced
+pub fn sync_to_owner_repos(
+    source_repo_path: &Path,
+    state: &RepositoryState,
+    db_repo_data: &RepositoryData,
+    git_data_path: &Path,
+) -> SyncResult {
+    let mut result = SyncResult::default();
+
+    // Collect authorized maintainers per owner
+    let by_owner = collect_authorized_maintainers(&db_repo_data.announcements);
+    let state_author = state.event.pubkey.to_hex();
+
+    debug!(
+        identifier = %state.identifier,
+        owners = by_owner.len(),
+        "Syncing git data to owner repositories"
+    );
+
+    for (owner, maintainers) in &by_owner {
+        // Check if this state's author is authorized for this owner
+        if !maintainers.contains(&state_author) {
+            debug!(
+                identifier = %state.identifier,
+                owner = %owner,
+                "Skipping owner - state author not in maintainer set"
+            );
+            continue;
+        }
+
+        // Find the previous latest state for this owner's maintainer set
+        let previous_state = db_repo_data
+            .states
+            .iter()
+            .filter(|s| maintainers.contains(&s.event.pubkey.to_hex()))
+            .max_by_key(|s| s.event.created_at);
+
+        // Only update if this state is newer than any existing state
+        // TODO: in event of a tie, the event with the biggest event id wins
+        if let Some(prev) = previous_state {
+            if state.event.created_at <= prev.event.created_at {
+                debug!(
+                    identifier = %state.identifier,
+                    owner = %owner,
+                    "Skipping owner - existing state is newer or equal"
+                );
+                continue;
+            }
+        }
+
+        // Find the announcement for this owner
+        let announcement = db_repo_data
+            .announcements
+            .iter()
+            .find(|a| a.event.pubkey.to_hex() == *owner);
+
+        let Some(announcement) = announcement else {
+            continue;
+        };
+
+        let target_repo_path = git_data_path.join(announcement.repo_path());
+
+        if !target_repo_path.exists() {
+            // Repository doesn't exist (e.g., announcement doesn't list this service)
+            debug!(
+                identifier = %state.identifier,
+                owner = %owner,
+                repo_path = %target_repo_path.display(),
+                "Skipping owner - repository doesn't exist"
+            );
+            continue;
+        }
+
+        // Copy missing OIDs from source repo to target repo if different
+        if target_repo_path != source_repo_path {
+            if let Err(e) = copy_missing_oids_between_repos(source_repo_path, &target_repo_path, state)
+            {
+                warn!(
+                    identifier = %state.identifier,
+                    source = %source_repo_path.display(),
+                    target = %target_repo_path.display(),
+                    error = %e,
+                    "Failed to copy OIDs between repos"
+                );
+                result.errors.push((target_repo_path.display().to_string(), e));
+                // Continue anyway - we'll try to align what we can
+            }
+        }
+
+        // Align refs with state
+        let align_result = align_repository_with_state(&target_repo_path, state);
+        result.repos_synced += 1;
+        result.refs_created += align_result.refs_created;
+        result.refs_updated += align_result.refs_updated;
+        result.refs_deleted += align_result.refs_deleted;
+        if align_result.head_set {
+            result.heads_set += 1;
+        }
+
+        info!(
+            identifier = %state.identifier,
+            owner = %owner,
+            repo_path = %target_repo_path.display(),
+            refs_created = align_result.refs_created,
+            refs_updated = align_result.refs_updated,
+            refs_deleted = align_result.refs_deleted,
+            head_set = align_result.head_set,
+            "Aligned repository with state"
+        );
+    }
+
+    info!(
+        identifier = %state.identifier,
+        repos_synced = result.repos_synced,
+        refs_created = result.refs_created,
+        refs_updated = result.refs_updated,
+        refs_deleted = result.refs_deleted,
+        heads_set = result.heads_set,
+        "Completed git data sync to owner repositories"
+    );
+
+    result
+}
+
+/// Copy missing OIDs from a source repository to a target repository.
+///
+/// Identifies commits referenced in the state that are missing from the target
+/// repository and copies them from the source repository using git fetch.
+pub fn copy_missing_oids_between_repos(
+    source_repo: &Path,
+    target_repo: &Path,
+    state: &RepositoryState,
+) -> Result<(), String> {
+    // Collect all commits referenced in the state
+    let mut commits_to_check = Vec::new();
+
+    for branch in &state.branches {
+        if !branch.commit.starts_with("ref: ") {
+            commits_to_check.push(&branch.commit);
+        }
+    }
+
+    for tag in &state.tags {
+        if !tag.commit.starts_with("ref: ") {
+            commits_to_check.push(&tag.commit);
+        }
+    }
+
+    // Identify missing commits
+    let mut missing_commits = Vec::new();
+    for commit in commits_to_check {
+        if !oid_exists(target_repo, commit) {
+            missing_commits.push(commit);
+        }
+    }
+
+    if missing_commits.is_empty() {
+        debug!(
+            "No missing commits to copy from {} to {}",
+            source_repo.display(),
+            target_repo.display()
+        );
+        return Ok(());
+    }
+
+    info!(
+        "Copying {} missing commits from {} to {}",
+        missing_commits.len(),
+        source_repo.display(),
+        target_repo.display()
+    );
+
+    // Fetch each missing commit from source to target
+    for commit in &missing_commits {
+        let output = Command::new("git")
+            .args([
+                "fetch",
+                source_repo.to_str().ok_or("Invalid source path")?,
+                commit,
+            ])
+            .current_dir(target_repo)
+            .output()
+            .map_err(|e| format!("Failed to execute git fetch: {}", e))?;
+
+        if !output.status.success() {
+            let stderr = String::from_utf8_lossy(&output.stderr);
+            return Err(format!(
+                "git fetch failed for commit {}: {}",
+                commit, stderr
+            ));
+        }
+
+        debug!("Copied commit {} to {}", commit, target_repo.display());
+    }
+
+    Ok(())
+}
+
+/// Align a repository's refs with the authorized state.
+///
+/// This function:
+/// 1. Deletes refs that are in the repo but not in the state (for refs/heads/ and refs/tags/)
+/// 2. Updates refs that exist in state if we have the commit
+/// 3. Sets HEAD if the HEAD branch's commit is available
+pub fn align_repository_with_state(repo_path: &Path, state: &RepositoryState) -> AlignmentResult {
+    let mut result = AlignmentResult::default();
+
+    // Check if repository exists
+    if !repo_path.exists() {
+        debug!(
+            "Repository not found at {}, cannot align with state",
+            repo_path.display()
+        );
+        return result;
+    }
+
+    // Get current refs from the repository
+    let current_refs = match git::list_refs(repo_path) {
+        Ok(refs) => refs,
+        Err(e) => {
+            warn!("Failed to list refs in {}: {}", repo_path.display(), e);
+            return result;
+        }
+    };
+
+    // Build expected refs from state
+    let mut expected_refs: HashMap<String, String> = HashMap::new();
+
+    for branch in &state.branches {
+        let ref_name = format!("refs/heads/{}", branch.name);
+        expected_refs.insert(ref_name, branch.commit.clone());
+    }
+
+    for tag in &state.tags {
+        let ref_name = format!("refs/tags/{}", tag.name);
+        expected_refs.insert(ref_name, tag.commit.clone());
+    }
+
+    // Delete refs that exist in repo but not in state (only for refs/heads/ and refs/tags/)
+    for (ref_name, _current_commit) in &current_refs {
+        if (ref_name.starts_with("refs/heads/") || ref_name.starts_with("refs/tags/"))
+            && !expected_refs.contains_key(ref_name)
+        {
+            match git::delete_ref(repo_path, ref_name) {
+                Ok(()) => {
+                    info!(
+                        "Deleted {} from {} (not in state)",
+                        ref_name,
+                        repo_path.display()
+                    );
+                    result.refs_deleted += 1;
+                }
+                Err(e) => {
+                    warn!(
+                        "Failed to delete {} from {}: {}",
+                        ref_name,
+                        repo_path.display(),
+                        e
+                    );
+                }
+            }
+        }
+    }
+
+    // Update refs that exist in state (if we have the commit)
+    for (ref_name, expected_commit) in &expected_refs {
+        // Skip symbolic refs
+        if expected_commit.starts_with("ref: ") {
+            continue;
+        }
+
+        // Check if we have the commit
+        if !git::oid_exists(repo_path, expected_commit) {
+            debug!(
+                "Commit {} not available for {} in {}",
+                expected_commit,
+                ref_name,
+                repo_path.display()
+            );
+            continue;
+        }
+
+        // Check current value
+        let current_commit = current_refs
+            .iter()
+            .find(|(r, _)| r == ref_name)
+            .map(|(_, c)| c.as_str());
+
+        if current_commit == Some(expected_commit.as_str()) {
+            // Already correct
+            continue;
+        }
+
+        // Update or create the ref
+        match git::update_ref(repo_path, ref_name, expected_commit) {
+            Ok(()) => {
+                if current_commit.is_some() {
+                    info!(
+                        "Updated {} to {} in {}",
+                        ref_name,
+                        expected_commit,
+                        repo_path.display()
+                    );
+                    result.refs_updated += 1;
+                } else {
+                    info!(
+                        "Created {} at {} in {}",
+                        ref_name,
+                        expected_commit,
+                        repo_path.display()
+                    );
+                    result.refs_created += 1;
+                }
+            }
+            Err(e) => {
+                warn!(
+                    "Failed to update {} in {}: {}",
+                    ref_name,
+                    repo_path.display(),
+                    e
+                );
+            }
+        }
+    }
+
+    // Set HEAD if specified in state
+    if let Some(head_ref) = &state.head {
+        if let Some(branch_name) = state.get_head_branch() {
+            if let Some(head_commit) = state.get_branch_commit(branch_name) {
+                match git::try_set_head_if_available(repo_path, head_ref, head_commit) {
+                    Ok(true) => {
+                        info!(
+                            "Set HEAD to {} in {}",
+                            head_ref,
+                            repo_path.display()
+                        );
+                        result.head_set = true;
+                    }
+                    Ok(false) => {
+                        debug!(
+                            "HEAD commit {} not available yet in {}",
+                            head_commit,
+                            repo_path.display()
+                        );
+                    }
+                    Err(e) => {
+                        warn!("Failed to set HEAD in {}: {}", repo_path.display(), e);
+                    }
+                }
+            }
+        }
+    }
+
+    result
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_sync_result_default() {
+        let result = SyncResult::default();
+        assert_eq!(result.repos_synced, 0);
+        assert_eq!(result.refs_created, 0);
+        assert_eq!(result.refs_updated, 0);
+        assert_eq!(result.refs_deleted, 0);
+        assert_eq!(result.heads_set, 0);
+        assert!(result.errors.is_empty());
+    }
+
+    #[test]
+    fn test_alignment_result_default() {
+        let result = AlignmentResult::default();
+        assert_eq!(result.refs_created, 0);
+        assert_eq!(result.refs_updated, 0);
+        assert_eq!(result.refs_deleted, 0);
+        assert!(!result.head_set);
+    }
+}