# @pi-unipi/fusion Local Fusion for UniPi: a Devin-inspired lead + persistent sidekick pair, a curated model preset, and a keyboard-first picker (`/unipi:model`). It uses pi's extension and RPC APIs natively. ## `/unipi:model` — the picker ``` ╭ Model ───────────────────────────────────────────────────────────────╮ │/ Type to search │ │───────────────────────────────────────────────────────────────────────│ │❭ Fusion ← ▰▰▰▱▱ → Medium Lead Fable… ▾ │ │· GLM-5.3 Flash ✱ ▰▰▰▰▰ Max │ │· openrouter · deepseek/deepseek-v4.1-flash ▰▰▱▱▱ High │ │ ↓ more below │ │ │ │ ━━━━━●━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ │ │ Input Cached input Output Sidekick input │ │ $10 / 1M $0.25 / 1M $50 / 1M $0.2 / 1M │ │ Sidekick cached input Sidekick output │ │ $0.02 / 1M $1.2 / 1M │ │ Model key openrouter/deepseek/deepseek-v4.1-flash │ │ │ │ ✱ New ✱ Promotion ✱ Beta · Pairs frontier intelligence with cost-efficient execution │ │↑↓ select · tab lead · ←→ effort · ↵ confirm · esc cancel │ ╰───────────────────────────────────────────────────────────────────────╯ ``` - **Row order**: the active selection pinned first, then the Fusion row (when a pair is configured), then recent (≤5, MRU), then the preset models, then **every other available model** — the catalogue is never hidden; the preset only controls ordering. When a single model is selected its row lights up with `✓`; when Fusion is selected the selection lives on the Fusion row and plain rows stay unmarked. - **`←`/`→`** steps the highlighted row's effort (pi thinking level: off → minimal → low → medium → high → xhigh → max) and it is **remembered per model**. The five-cell bar fills with `▰` and uses `▱` for remaining levels. The Fusion row keeps its own lead/sidekick efforts, so adjusting Fusion never rewrites a model's standalone level. - **`tab`** on the Fusion row cycles focus: effort → lead → sidekick (`shift+tab` reverses). Focused columns open an inline dropdown over the preset lists; `↵` applies, `esc` collapses. - **Price panel**: the highlighted model's blended price is marked on a logarithmic red→orange→yellow→green→cyan→blue→violet slider. Fusion shows `Input`, `Cached input`, `Output`, `Sidekick input`, `Sidekick cached input`, and `Sidekick output`, and the exact registry key of the highlighted row is spelled out (`Model key openrouter/deepseek/deepseek-v4.1-flash`; both the lead and sidekick keys on the Fusion row). - **Name column & provider**: the name column sizes itself to the widest row label (minimum 24 columns) up to the terminal width, and the effort control stays right-anchored — so wide terminals show full names. A row only gets a dim `provider · ` prefix when its display name is ambiguous: it contains a `/` (`deepseek/deepseek-v4.1-flash` reads like a key) or the same friendly name is offered by more than one provider. Unique names stay clean, and the prefix is never truncated. - **Confirm** applies: `pi.setModel`, `pi.setThinkingLevel(effort)`, updates MRU + persisted active selection, and shows `Fusion · Lead ◆ Sidekick` in the footer. Switching the model through pi's own `/model`/Ctrl+P drops Fusion mode. - Because pi intercepts `/model` inside its editor before extensions run, the command cannot be replaced — instead typing `/model` pins `/unipi:model` as the **first autocomplete suggestion**. - Fast Mode is not implemented because pi has no equivalent capability. Hand-edited preset badge metadata renders `✱` as New, Promotion, or Beta: ```json {"badges": {"provider/model": "new"}} ``` ## `/unipi:fusion-preset` — curation Two-column checklist over every available model: ``` ╭ Fusion preset ───────────────────────────────────────────────────────╮ │Fusion preset · 2 lead · 2 sidekick · writes to global │ │Search: (type to filter) │ │ L S model │ │ › [x] [ ] provider/lead │ │ [ ] [x] provider/sidekick │ │↑↓ select · ←→ column · space toggle sidekick · Enter save · esc cancel │ ╰───────────────────────────────────────────────────────────────────────╯ ``` - `←`/`→` (or `tab`) switches the L/S column, `space` toggles membership, `Enter` saves & closes, `esc` cancels, and typing filters. Selected models float to the top so the curated set is always visible. - Defaults are not edited here: confirming a Fusion pair in `/unipi:model` records it as the preset default. Any model key in the registry is allowed — there is no OAuth/subscription gate. ## Persistent sidekick Confirming a Fusion pair selects the lead for the session. The `sidekick` tool runs one lazy-spawned child pi per lead session; its session file is persisted at `~/.unipi/state/fusion/sidekick/.jsonl`. Context and shells persist across handoffs. The sidekick's context compacts independently of the lead's (it is its own pi session). `sidekick({message, block:true})` waits by default; `block:false` returns immediately and delivers a ``. Calling it while busy steers the same handoff. A handoff whose lead turn has ended — started with `block:false`, abandoned by a user message, or timed out — still wakes the lead with that same completion notification when its report lands, exactly once. Background tasks keep that handoff open through their completion notification and any follow-up turn, so the report is not released at an intermediate checkpoint. If a prompt arrives while the child is processing, Fusion retries it once with pi's `followUp` streaming behavior. Sidekick work renders as ordinary tool activity — handoff ids, `agent_id`, and `read_subagent` protocol text never reach the terminal. Sidekick output keeps that same format on the main surface, marked as sidekick-origin by a `▍` rail. While the sidekick works and the lead's turn is over, an animated `sidekick working` line above the editor shows the live tool count and elapsed time until the report lands. `read_subagent({agent_id?, block?, timeout?})` reads or waits for a handoff. The child receives `UNIPI_FUSION_CHILD=1` and `UNIPI_SUBAGENT_CHILD=1`; the Fusion extension guard prevents child processes from registering Fusion tools, commands, or lead policy. The lead gets the persistent delegation policy through `before_agent_start`, and the first direct `edit`/`write` receives a one-time delegation nudge. `/unipi:fusion-stats` reports sidekick tokens, costs at sidekick and lead rates, estimated savings, handoff count, and runtime state. The footer shows savings above `$0.005`. ## Storage ```json // ~/.unipi/config/fusion/preset.json (global) // /.unipi/fusion-preset.json (project override; lists replace, objects merge) { "schema_version": 1, "lead": ["provider/lead"], "sidekick": ["provider/sidekick"], "default": {"lead": "provider/lead", "sidekick": "provider/sidekick"}, "effort": {"provider/sidekick": "high"}, "badges": {"provider/sidekick": "new"}, "prices": {"provider/sidekick": {"input": 0.2, "cachedInput": 0.02, "output": 1.2}}, "recent": ["provider/lead"], "active": {"kind": "fusion", "lead": "provider/lead", "sidekick": "provider/sidekick"} } ``` `prices` is an optional manual override for models whose provider reports no pricing. ## Status - [x] Preset store, project layering, curation UI, autocomplete boost - [x] Picker effort bars, price slider, price panel, badges, legend - [x] Persistent sidekick runtime, blocking/non-blocking tools, steering, progress, completion card, session isolation - [x] Lead policy, first-edit nudge, savings estimate, footer and stats command