openhuman/docs/tinyagents-vendor-improvement-plan/00-audit-harness.md

00 — Harness Audit: what remains in OpenHuman, what can migrate

Ground truth as of 2026-07-04, main + waves 1–2 (#4473, #4483).

Scope totals (incl. tests):

Tree	LOC	Notes
src/openhuman/agent/	~56,951	this audit's core scope
src/openhuman/agent_orchestration/	~25,749	lifecycle glue over SDK graphs
src/openhuman/tinyagents/	~12,185	the live adapter seam (all turns route here)
src/openhuman/inference/	~52,955	provider layer; does NOT wrap tinyagents

Classification legend: (a) thin adapter over tinyagents · (b) migratable/duplicative generic harness logic · (c) product policy, stays · (d) unclear.

1. Where execution already lives on tinyagents

Chat turns (harness/session/turn/core.rs → turn/graph.rs), channel/CLI turns (harness/graph.rs, entry agent/bus.rs agent.run_turn), and sub-agent turns (harness/subagent_runner/ops/graph.rs) all route through run_turn_via_tinyagents_shared in the src/openhuman/tinyagents/ adapter. Middleware, stop hooks, unknown-tool policy, and context compression are on SDK middleware. The legacy run_tool_call_loop is deleted.

Direct tinyagents:: references inside agent/ are sparse by design — the adapter module owns the seam. Highest densities: subagent_runner/ops/runner.rs and ops/graph.rs (15 refs each), turn/core.rs (13).

2. Remaining subsystems, ranked by migratable size

1. Session/transcript shell — harness/session/, ~13.2k LOC. Transcript read/write + dialect-suffix compat (transcript.rs 1347+978 tests), builder assembly (builder/factory.rs 1312 — product, stays), turn IO (session_io.rs), migration (373), progress projection (tool_progress.rs 252). Duplicates crate Store/AppendStore/ StoreChatHistory. Old-plan C1 covers the cutover; dual-writes are ON, shadow reads landed (flag OFF). Biggest single unlock (~9–11k incl. session_db/subagent_sessions/session_import).
2. Sub-agent runner — harness/subagent_runner/, ~6.1k LOC. Prepare → filter tools → run child → checkpoint → extract → mirror. Duplicates SubAgent/SubAgentSession/SubAgentTool + graph::subagent_node. extract_tool.rs (612) + handoff.rs (287) are generic (old-plan C5/C6); tool_prep.rs allowlist half is product.
3. Orchestration lifecycle glue — agent_orchestration/, ~3.7k of it. running_subagents.rs 1931 (target ≤300; watch channels, abort/wait/ steer, tombstones — belongs on a durable TaskStore, see 06), spawn_parallel_graph.rs 1764 (dup of map_reduce).
4. Progress/streaming projection — ~2.9k LOC. progress.rs (303, AgentProgress incl. ThinkingDelta/SubagentThinkingDelta/ ToolCallArgsDelta), session/tool_progress.rs (252, bridges ProviderDelta → AgentProgress), progress_tracing.rs + langfuse.rs
   • tests (~2k). Duplicates crate AgentEvent/HarnessEventJournal/ Langfuse exporters. Deletion gated on old-plan C4 journal parity and on crate streaming fixes (docs 02/03 here) so nothing regresses in the UI.
5. Tool-call dialects — ~1.9k LOC. dispatcher.rs (609) ToolDispatcher trait (native/XML/P-Format), harness/parse.rs (833) permissive XML/JSON parser with arg-key drift recovery, pformat.rs (499) compact positional name[a|b] calls (~80% token cut, OpenHuman-invented). Live path is native; these survive for prompt-guided dialects + transcript compat. Extraction candidate (06) so the C1 read-cutover becomes a pure delete.
6. Multimodal assembly — multimodal.rs 1690 (+1020 tests). [IMAGE:]/[FILE:] markers → provider content blocks, mime allowlist, PDF extraction, fetch gating, truncation budgets. ~1550 generic (06).
7. Cost — cost.rs 343. Per-turn USD + tier pricing + budget stop-hook feed. Blocked on crate Usage having no money field and reasoning_tokens never being populated (see 01/02). Old-plan C3 flip criteria stand.
8. Tool policy/filter — tool_policy.rs 524 + harness/tool_filter.rs 299. Overlaps crate ToolPolicy; residual gap is free-form model-visible ToolSchema metadata (sdk-gaps §1).

3. Confirmed product — keep in OpenHuman

• triage/ (3.8k) — trigger classification; invokes the migrated loop. ~800-line generic evaluator core is an extraction candidate (06), envelope/ escalation/events stay.
• task_dispatcher/ (1.6k) — deterministic card dispatch (CAS claim → autonomous turn). Mechanics shrink onto graph::todos (old-plan C2).
• archivist/ (1.4k + 1k tests) — episodic indexing/lessons; memory policy.
• prompts/ (~4k) — section assembly/rendering; product voice.
• agent/tools/ (~4k) — product tools (run_workflow, preferences, delegate_to_personality, todo CRUD → C2 projections).
• builder/factory.rs, definitions (definition.rs 846, definition_loader.rs, builtin_definitions.rs), memory_context.rs, memory_protocol.rs, credentials/sandbox context, debug/, library/, bus.rs, schemas.rs.
• inference/ (53k) — stays for credential ownership, billing classification, OAuth, local/Ollama. Largest parallel duplication of a tinyagents capability in the tree, but per the standing verdict (reliable.rs 900) not forced; revisit only after a native Anthropic provider (05) proves out.

4. Streaming & reasoning today (OpenHuman side)

Provider deltas (inference::provider::ProviderDelta::{TextDelta, ThinkingDelta, ToolCallArgsDelta}) are bridged in session/tool_progress.rs:226 into AgentProgress, a per-request mpsc::Sender channel distinct from the DomainEvent bus. Reasoning reaches the UI only through this OpenHuman-side path (plus the ThinkingForwarder shim), because the crate drops reasoning (01 §3). Fixing 02/03 in the vendor crate lets AgentProgress become a thin projection of crate AgentEvents and unblocks deleting ThinkingForwarder, tool_progress.rs, and eventually the progress_tracing stack.

5. Delta vs the old plan's inventory

The C0–C7 verdicts hold. New/raised items from this sweep:

• running_subagents.rs keeps growing (1931; was flagged at the same size on 2026-07-03 — enforce the ≤300 target when C6 lands or it accretes further).
• The dialect layer's delete gate ("no live path parses provider text") is reachable only after C1 phase 3 and either upstreaming P-Format/XML parsing (06) or accepting native-only transcripts.
• inference/provider/reliable.rs verdict unchanged, but 05 (native Anthropic in-crate) is the first concrete step that could eventually make routing non-turn provider calls through the crate harness attractive.