Raxol

Raxol Skill

Elixir TEA framework for terminal UIs + AI agent orchestration. The same TEA model runs in the terminal, browser (LiveView), SSH, and as MCP tools/resources. OTP provides supervision, crash isolation, and hot reload.

Raxol v2.6 is a 15-package monorepo (Elixir 1.20 / OTP 29). The packages this skill covers:

• raxol_core -- TEA runtime, buffer/rendering, events, directives, telemetry
• raxol -- umbrella + terminal surface (termbox2 NIF + IO fallback)
• raxol_agent -- agent framework: TEA/Process agents, turn driver, memory, self-improving skills, backends, harnesses, teams
• raxol_mcp -- MCP server/client: tool auto-derivation, focus lens, resources
• raxol_liveview -- Phoenix LiveView bridge (buffer -> HTML, a11y)
• raxol_plugin, raxol_sensor -- plugin SDK, sensor fusion

Payments/ACP (raxol_payments, raxol_acp) and the Symphony orchestrator (raxol_symphony) have their own skills -- see below.

What You Get

• TEA agent and Process agent patterns with lifecycle examples
• Turn driver + memory stack + self-improving skills (v2.6)
• Workflow engine: graph DSL, checkpointing, human-in-the-loop, saga rollback
• AI backends (HTTP, Mock, native ClaudeCode/Cursor, OpenRouter) + harness selection
• MCP server (auto-derive tools from the widget tree) and MCP client
• LiveView surface (buffer -> HTML, themes, accessibility)
• Multi-agent orchestration (teams, cockpit, message protocol)
• Headless sessions and agent testing patterns (unit, integration, E2E)

Two Agent Models

	TEA Agent (use Raxol.Agent)	Process Agent (use Raxol.Agent.UseProcess)
Loop	Message-driven (update/2)	Tick-driven (observe/think/act)
Rendering	Optional view/1	Headless only
Input	Messages from agents, commands, MCP	Events buffer, directives
Best for	Agents with UI, reactive workflows	Autonomous background agents
Crash recovery	OTP restart, fresh init/1	context_snapshot + restore_context
AI backend	Manual (call in async commands)	Built-in via Strategy

For a full LLM chat turn (memory + skills + user model + tool loop) use the Raxol.Agent.Turn driver -- see agents/turn-memory.md.

See also

• raxol-payments -- agentic commerce: Xochi/Riddler/ACP, agent wallets, privacy tiers
• raxol-symphony -- tracker-driven coding-agent orchestrator (Symphony)
• droo-stack -- general Elixir patterns (pipes, pattern matching, ExUnit)
• design-ux -- TUI design principles (terminal layout, box-drawing, density)
• claude-api -- Anthropic SDK integration in Elixir

Reading Guide

Task	File
Build a TEA agent + messaging	agents/tea-agent.md
Build an autonomous agent	agents/process-agent.md
Full LLM turn: memory + skills	agents/turn-memory.md
Reusable actions / LLM tools	agents/actions-pipelines.md
Multi-agent teams / cockpit	agents/teams-orchestrator.md
Orchestrate steps as a graph	workflow/graph.md
AI backend + harness selection	ai/backends.md
Consume external MCP servers	ai/mcp-client.md
Expose your app as MCP tools	mcp/server.md
Render a TEA app in LiveView	surfaces/liveview.md
Headless sessions + MCP tools	headless/sessions.md
Testing agents and actions	testing/agent-testing.md

Message Protocol

All TEA agents receive these in update/2. Defined once here, referenced from other files.

# Async message from another agent
{:agent_message, from_id, payload}

# Sync call -- MUST reply with send(pid, {:agent_reply, ref, reply})
{:call, caller_pid, ref, message}

# Team broadcast
{:team_broadcast, team_id, payload}

# Async command / directive results
{:command_result, result}
{:command_result, {:shell_result, %{output: string, exit_status: int}}}
{:command_result, {:action_result, module, result_map}}
{:command_result, {:action_error, module, reason}}
{:command_result, {:pipeline_result, result_map}}
{:command_result, {:pipeline_error, step_module, reason}}

Key Conventions

• All agents auto-register in Raxol.Agent.Registry by :id
• Always return {model, command} from update/2, never bare model
• view/1 returning nil = headless (no rendering overhead)
• Effects are struct-based Directives (v2.6): Raxol.Core.Runtime.Directive (stop/1, schedule/2, spawn_task/1) and Raxol.Agent.Directive (async/1, shell/2, send_agent/2). The use Raxol.Agent helpers wrap these.
• Session agents register as agent_id, Process agents as {:process, agent_id}, MCP clients as {:mcp_client, name}
• Agent package: packages/raxol_agent/

Common Pitfalls

1. Wrong update/2 return -- must return {model, Command.none()} not bare model
2. Forgetting call reply -- {:call, pid, ref, msg} requires send(pid, {:agent_reply, ref, reply}); caller blocks with timeout
3. Mixing agent models -- TEA callbacks and ProcessBehaviour callbacks are separate behaviours
4. Sync call deadlocks -- Agent A calls B, B calls A = deadlock. Break cycles with async send_agent/2
5. String vs atom keys -- Headless send_key uses atoms for special keys (:tab), strings for characters ("q")
6. Real backends in tests -- always use Backend.Mock, never HTTP

Design Context

Raxol treats each rendering surface (terminal, web, SSH, MCP) as a functor from the TEA model. Same update/2, same model, different projections. In v2.6 MCP is a first-class surface (raxol_mcp): widgets auto-export tools via the Raxol.MCP.ToolProvider behaviour, model state is exposed via ResourceProvider, and FocusLens filters tools by attention. When building features, consider how they surface as MCP tools -- see mcp/server.md.