openhuman/docs/plans/rlm-workflows

RLM — Language-Based Workflows (Rhai/.ragsh) Integration Plan

Goal: expose TinyAgents' Rhai-backed REPL language (the .ragsh / RLM / CodeAct surface, gated behind the repl cargo feature in vendor/tinyagents/Cargo.toml) as a first-class rlm tool in the OpenHuman Rust core, so the orchestrator agent can write its own workflow scripts — fan-out over subagents, batched tool/model calls, loops, conditionals — and execute them deterministically, similar to Claude Code Workflows and Recursive Language Models (RLMs).

Why

Today the orchestrator composes work through fixed primitives: spawn_subagent, spawn_parallel_agents, run_workflow (WORKFLOW.md bundles), and typed tinyflows graphs. None of these let the model express ad-hoc control flow — "spawn N readers, dedupe their findings, verify each survivor with 3 refuters, loop until dry". The .ragsh session in TinyAgents is exactly that surface: a sandboxed, policy-bounded scripting engine whose only host access is capability functions (model_query, tool_call, agent_query, batched variants), with fail-closed limits on operations, wall-clock time, output bytes, call counts, and recursion depth.

Architecture summary

Orchestrator model turn
  └─ rlm tool call { script, session_id?, timeout_secs?, limits? }
       └─ src/openhuman/rlm/  (new domain)
            ├─ session manager  (persistent ReplSession per rlm session_id)
            ├─ capability bridge (openhuman Tools/Subagents/Provider →
            │                     tinyagents CapabilityRegistry)
            ├─ policy mapping   (autonomy tier + SecurityPolicy → ReplPolicy)
            ├─ progress bridge  (ReplCallRecord / EventSink → AgentProgress
            │                     + DomainEvent bus)
            └─ tinyagents::ReplSession::eval_cell  (spawn_blocking)
                 └─ rhai engine — model_query / tool_call / agent_query /
                    *_batched / emit / answer  (fail-closed ReplPolicy)

Two repos change:

1. vendor/tinyagents (submodule, separate PR against tinyhumansai/tinyagents): host-embedding gaps — external cancellation flag, live capability-call events on the EventSink, async-embedding documentation. Branch: feat/repl-host-embedding.
2. openhuman (one gigantic PR against tinyhumansai/openhuman): the repl feature flag, the new src/openhuman/rlm/ domain, the rlm tool, prompt/docs surfacing, and tests. Branch: feat/rlm-language-workflows, including the submodule pointer bump once the tinyagents PR lands.

Phases

Phase	File	Deliverable
1	phase-1-research.md	Research findings: what tinyagents repl provides, what openhuman provides, the gaps
2	phase-2-tinyagents.md	TinyAgents-side changes (cancellation, live events) — separate PR
3	phase-3-rlm-domain.md	src/openhuman/rlm/ domain: sessions, capability bridge, policy
4	phase-4-rlm-tool.md	First-class rlm tool: schema, registration, prompt surfacing
5	phase-5-hardening.md	Error handling, timeouts, cancellation, limits, observability
6	phase-6-tests.md	Tests (written last): unit, timeout/cancel/limit, RPC E2E
7	phase-7-delivery.md	PR strategy: tinyagents PR + one gigantic openhuman PR

Tests are deliberately the final implementation phase (per the feature brief): phases 3–5 land the behavior with verbose debug logging; phase 6 back-fills unit and E2E coverage to the ≥80% changed-line gate before the PR is opened.