A3S Code
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  • v9.1.0

      • Commands

      A3S Code is primarily SDK-driven. Product CLIs and UIs usually map commands to session APIs rather than depending on a large public command protocol.

      This page describes the session command registry. For the commands that the 9.0.0 terminal client handles itself, see A3S Code TUI.

      The surfaces are intentionally different:

      SurfaceOwnerPurpose
      Built-in session commandsRuntime/help, /compact, /cost, /model, /clear, /history, /tools, and /mcp, available in every session through session.send.
      Host command registryHost applicationProduct-defined commands registered with session.registerCommand(...) and invoked through session.send("/name args").
      a3s-code-tui commandsTerminal client/help, /model, /clear, /exit, and /quit, handled by the TUI when the line is a single token; other lines go to the session.

      SDK commands execute before the LLM sees the input. A handler receives the raw argument string plus session metadata, and returns display text. Use commands for thin control-plane actions; use normal SDK methods for workflows, tools, verification, and persistence.

      User actionSession API
      Send a promptsession.send(prompt)
      Stream a promptsession.stream(prompt)
      Redirect the active runsession.steer(text)
      Stop the active runsession.interrupt()
      Answer a pending confirmationsession.confirmToolUse(toolId, approved)
      Ask a side questionCreate a separate session; explicit history on the same session is still recorded in its fact log.
      Run a deterministic toolsession.tool(name, args)
      Read historysession.history()
      Save statesession.save()
      Resume stateagent.resumeSession(id, options)
      Inspect toolssession.toolNames() / session.toolDefinitions()
      Verify worksession.verifyCommands(subject, commands)
      Replay run statesession.runs() / session.runEvents(runId)
      Inspect or cancel the current runsession.currentRun() / session.cancelRun(runId)

      Building Slash Commands

      If your app exposes slash commands, keep them thin. Register the handler, list the available commands, and invoke the command through session.send():

      TypeScript
      session.registerCommand(

        'docs_status',

        'Return docs command status',

        (args, ctx) => {

          return `status args=${args}; session=${ctx.sessionId}; workspace=${ctx.workspace}`;

        },

      );

      

      console.log(session.listCommands());

      

      const result = await session.send('/docs_status check');

      console.log(result.text);

      Command handlers should not hide long-running work. If a command needs to run tools, verify output, fan out to subagents, or schedule recurring automation, have the handler return a short acknowledgement and run that work through explicit host code. That keeps cancellation, audit, and permissions visible.