Session name '{}' already exists. Use a different name or re

Error message

Session name '{}' already exists. Use a different name or remove it first.

What it means

Thrown when saving a named session to the session index: the index file maps session names to session data, and names must be unique. Before inserting, the code checks `index.sessions.contains_key(name)` and bails if the name is already taken. It is a user-facing guard against silently overwriting an existing saved session.

Source

Thrown at src/ai.rs:15069

        session_provider,
        codex_launch_target,
        explicit_session_requested,
    )
}

/// Save a session with a name.
fn save_session(name: &str, id: Option<String>) -> Result<()> {
    let session_id = match id {
        Some(id) => id,
        None => get_most_recent_session_id()?
            .ok_or_else(|| anyhow::anyhow!("No sessions found. Start an AI session first."))?,
    };

    let mut index = load_index()?;

    // Check if name already exists
    if index.sessions.contains_key(name) {
        bail!(
            "Session name '{}' already exists. Use a different name or remove it first.",
            name
        );
    }

    let session_provider = read_sessions_for_project(Provider::All)?
        .into_iter()
        .find(|session| session.session_id == session_id)
        .map(|session| session.provider)
        .unwrap_or(Provider::Claude);

    let saved = SavedSession {
        id: session_id.clone(),
        provider: provider_name(session_provider).to_string(),
        description: None,
        saved_at: chrono::Utc::now().to_rfc3339(),
        last_resumed: None,
    };

View on GitHub (pinned to a747e741ae)

Solutions

Choose a different, unique name for the new session
Run the session remove/delete command for the existing name first, then save again
List saved sessions (`f ai sessions list`) to see which entry occupies the name
If the old entry is stale, delete the sessions index entry manually in .ai/ and retry

Example fix

// before
f ai sessions save --name work
// error: name already exists
// after
f ai sessions remove work
f ai sessions save --name work

Defensive patterns

Strategy: validation

Validate before calling

# shell: check the name is free before saving
if f ai sessions list | grep -qxF "$NAME"; then
  echo "name '$NAME' taken; pick another"; exit 1
fi
f ai sessions save --name "$NAME"

Try / catch

// treat 'already exists' as retry-with-new-name
match save_session(name, data) {
    Err(e) if e.to_string().contains("already exists") => {
        let unique = format!("{}-{}", name, timestamp());
        save_session(&unique, data)?;
    }
    other => other?,
}

Prevention

Adopt a naming scheme with timestamps or branch names
List sessions before saving to spot existing names
Remove old sessions instead of reusing their names
Keep one canonical .ai index per project, not per machine copy

When it happens

Trigger: Calling the session-save command with `--name <name>` (or equivalent) where `<name>` already exists in the sessions index loaded via load_index().

Common situations: Re-running a save command with the same mnemonic name; scripting saves that reuse a fixed name; restoring an index from backup that already contains the name; forgetting a previous save under the same alias.

Related errors

AI-assisted analysis of nikivdev/code@a747e741ae (2026-09-01). Data as JSON: /api/errors/f0782aedfe49e9a8. Report an issue: GitHub.