Function build_session

core/src/serve/daemon.rs:105–139

Build one durable serve session under the explicit `session_id` (`schedule: `), injecting the agent dir's prompt slots, skills, and `tools/`. Rehydrate-on-boot: if a `SessionStore` is configured (via `extra`) and already holds `session_id`, RESUME it so prior context is restored; otherwise create a fresh session. Resume re-applies the freshly loaded prompt slots / skills / tools (it restores

(
    agent: &Agent,
    agent_dir: &AgentDir,
    session_id: String,
    workspace: impl Into<String>,
    extra: &SessionOptions,
)

/// The caller owns the id; a host-set `extra.session_id` is intentionally ignored
/// (it would collide every schedule onto one shared, store-clobbering id).
async fn build_session(
    agent: &Agent,
    agent_dir: &AgentDir,
    session_id: String,
    workspace: impl Into<String>,
    extra: &SessionOptions,
) -> Result<AgentSession> {
    let mut opts = extra.clone();
    if opts.prompt_slots.is_none() {
        opts.prompt_slots = Some(agent_dir.prompt_slots.clone());
    }
    opts.skill_dirs
        .extend(agent_dir.config.skill_dirs.iter().cloned());
    opts.session_id = Some(session_id.clone());

    // Resume only when the store already has this session; the borrow of
    // `opts.session_store` is released before `opts` is moved into the chosen
    // builder. `exists` returns the crate Result, so `?` propagates cleanly.
    let resume = match &opts.session_store {
        Some(store) => store.exists(&session_id).await?,
        None => false,
    };
    let session = if resume {
        agent.resume_session(&session_id, opts)?
    } else {
        agent.session(workspace, Some(opts))?
    };

    // Install the agent dir's tools/ (MCP servers + sandboxed scripts) into the
    // session, so a triggered turn can call them. Connection is fallible and
    // surfaces here (fail at startup, not at first call). Done for both fresh and
    // resumed sessions — tools are not persisted, they are re-installed each boot.
    super::tools::install_agent_dir_tools(&session, &agent_dir.tools).await?;
    Ok(session)
}

#[cfg(test)]
mod tests {