enhancement: add an experimental, reversible Codex thread-history migration

crates/cli/src/agents/codex/install.rs

@@ -7,10 +7,74 @@ use crate::agents::CodingAgent;
 use crate::error::CliError;
 use crate::installation::{InstallRequest, UninstallRequest};
 
+use super::history;
+
 pub(crate) fn install(command: InstallRequest) -> Result<ExitCode, CliError> {
-    crate::installation::marketplace::install(CodingAgent::Codex, command)
+    let migrate_history = command.migrate_history;
+    let dry_run = command.dry_run;
+    let history_database = command.history_database.clone();
+    let status = crate::installation::marketplace::install(CodingAgent::Codex, command)?;
+    if status != ExitCode::SUCCESS || !migrate_history {
+        return Ok(status);
+    }
+    // The provider must exist in config.toml before threads are pointed at it,
+    // so migrate only after the install itself has succeeded.
+    //
+    // A failure here is reported as a nonzero status rather than an error: the
+    // integration is installed and working, and calling it an install failure
+    // would send the caller to the wrong remedy.
+    match history::migrate_to_relay(dry_run, history_database.as_deref()) {
+        Ok(_) => Ok(status),
+        Err(error) => {
+            log::error!(
+                target: "nemo_relay.installation",
+                event = "codex_history_migration_failed",
+                host = "codex",
+                error_kind = "history_migration";
+                "Codex integration installed but thread-history migration failed"
+            );
+            println!("the Codex integration is installed, but history migration failed: {error}");
+            println!(
+                "retry the migration with `nemo-relay install codex --force --migrate-history`."
+            );
+            Ok(ExitCode::FAILURE)
+        }
+    }
 }
 
 pub(crate) fn uninstall(command: UninstallRequest) -> Result<ExitCode, CliError> {
-    crate::installation::marketplace::uninstall(CodingAgent::Codex, command)
+    let skip_history_migration = command.skip_history_migration;
+    let dry_run = command.dry_run;
+    let history_database = command.history_database.clone();
+    let status = crate::installation::marketplace::uninstall(CodingAgent::Codex, command)?;
+    if status != ExitCode::SUCCESS || skip_history_migration {
+        return Ok(status);
+    }
+    // Reversal is inferred from the migration journal rather than a flag, so a
+    // user who migrated at install time does not have to remember to ask for it
+    // again here.
+    //
+    // As with install, a failure here is a nonzero status rather than an error.
+    // The integration is already removed; the journal survives so a later
+    // uninstall can still reverse the migration.
+    match history::restore_from_relay(dry_run, history_database.as_deref()) {
+        Ok(_) => Ok(status),
+        Err(error) => {
+            log::error!(
+                target: "nemo_relay.installation",
+                event = "codex_history_restore_failed",
+                host = "codex",
+                error_kind = "history_migration";
+                "Codex integration uninstalled but thread-history restore failed"
+            );
+            println!(
+                "the Codex integration is uninstalled, but restoring thread history failed: {error}"
+            );
+            println!(
+                "thread history is still recorded under the Relay provider; resuming those threads \
+                 fails until it is restored."
+            );
+            Ok(ExitCode::FAILURE)
+        }
+    }
 }

crates/cli/src/agents/codex/mod.rs

@@ -8,6 +8,7 @@ use super::AgentDescriptor;
 pub(super) mod app_server;
 pub(super) mod assets;
 pub(crate) mod doctor;
+pub(super) mod history;
 pub(super) mod host;
 pub(crate) mod install;
 pub(crate) mod launch;

crates/cli/src/commands/install.rs

@@ -21,6 +21,17 @@ pub(crate) struct InstallCommand {
     pub(crate) dry_run: bool,
     #[arg(long)]
     pub(crate) skip_doctor: bool,
+    /// Experimental: move existing Codex thread history onto the Relay provider so it stays
+    /// visible in the Codex resume picker. `nemo-relay uninstall codex` reverses this
+    /// automatically. Requires the `sqlite3` command on PATH, which Windows does not provide by
+    /// default.
+    #[arg(long)]
+    pub(crate) migrate_history: bool,
+    /// Codex thread database to migrate, when Codex has moved past the default schema
+    /// generation. Accepts a bare file name such as `state_6.sqlite`, resolved inside the Codex
+    /// home, or a full path. Requires `--migrate-history`.
+    #[arg(long, value_name = "PATH")]
+    pub(crate) history_database: Option<PathBuf>,
 }
 
 #[derive(Debug, Clone, Args)]
@@ -34,6 +45,13 @@ pub(crate) struct UninstallCommand {
     pub(crate) force: bool,
     #[arg(long)]
     pub(crate) dry_run: bool,
+    /// Leave migrated Codex thread history on the Relay provider instead of restoring it.
+    #[arg(long)]
+    pub(crate) skip_history_migration: bool,
+    /// Codex thread database to restore, overriding the one the migration recorded. Accepts a bare
+    /// file name such as `state_6.sqlite`, resolved inside the Codex home, or a full path.
+    #[arg(long, value_name = "PATH")]
+    pub(crate) history_database: Option<PathBuf>,
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, ValueEnum)]
@@ -66,6 +84,8 @@ impl InstallCommand {
             force: self.force,
             dry_run: self.dry_run,
             skip_doctor: self.skip_doctor,
+            migrate_history: self.migrate_history,
+            history_database: self.history_database,
         }
     }
 }
@@ -76,12 +96,24 @@ impl UninstallCommand {
             install_dir: self.install_dir,
             force: self.force,
             dry_run: self.dry_run,
+            skip_history_migration: self.skip_history_migration,
+            history_database: self.history_database,
         }
     }
 }
 
 pub(super) fn install(command: InstallCommand) -> Result<ExitCode, CliError> {
     let target = command.host;
+    if command.migrate_history && matches!(target, InstallTarget::ClaudeCode) {
+        return Err(CliError::Install(
+            "--migrate-history applies to the Codex integration only".into(),
+        ));
+    }
+    if command.history_database.is_some() && !command.migrate_history {
+        return Err(CliError::Install(
+            "--history-database requires --migrate-history".into(),
+        ));
+    }
     let request = command.into_runtime();
     let candidates = target.agents();
     let agents = if target.is_all() {
@@ -104,6 +136,21 @@ pub(super) fn install(command: InstallCommand) -> Result<ExitCode, CliError> {
 
 pub(super) fn uninstall(command: UninstallCommand) -> Result<ExitCode, CliError> {
     let target = command.host;
+    if command.skip_history_migration && matches!(target, InstallTarget::ClaudeCode) {
+        return Err(CliError::Install(
+            "--skip-history-migration applies to the Codex integration only".into(),
+        ));
+    }
+    if command.history_database.is_some() && matches!(target, InstallTarget::ClaudeCode) {
+        return Err(CliError::Install(
+            "--history-database applies to the Codex integration only".into(),
+        ));
+    }
+    if command.history_database.is_some() && command.skip_history_migration {
+        return Err(CliError::Install(
+            "--history-database cannot be combined with --skip-history-migration".into(),
+        ));
+    }
     let request = command.into_runtime();
     let candidates = target.agents();
     let agents = if target.is_all() {

crates/cli/src/commands/integrations.rs

@@ -78,6 +78,10 @@ fn refresh(command: RefreshCommand) -> Result<ExitCode, CliError> {
             force: true,
             dry_run: command.dry_run,
             skip_doctor: false,
+            // Refresh repairs an existing installation; any recorded history
+            // migration stays recorded and does not need to run again.
+            migrate_history: false,
+            history_database: None,
         };
         let result = match crate::agents::install_integration(agent, request) {
             Ok(status) if status == ExitCode::SUCCESS => Ok(()),

crates/cli/src/installation/mod.rs

@@ -15,11 +15,19 @@ pub(crate) struct InstallRequest {
     pub(crate) force: bool,
     pub(crate) dry_run: bool,
     pub(crate) skip_doctor: bool,
+    /// Experimental: rewrite pre-install Codex thread history onto the Relay provider.
+    pub(crate) migrate_history: bool,
+    /// Codex thread database to migrate, when it is not the default generation.
+    pub(crate) history_database: Option<PathBuf>,
 }
 
 #[derive(Debug, Clone)]
 pub(crate) struct UninstallRequest {
     pub(crate) install_dir: Option<PathBuf>,
     pub(crate) force: bool,
     pub(crate) dry_run: bool,
+    /// Skip the reversal that a recorded history migration would otherwise infer.
+    pub(crate) skip_history_migration: bool,
+    /// Codex thread database to restore, overriding the one the journal recorded.
+    pub(crate) history_database: Option<PathBuf>,
 }