Frontier AI,shipped in your hand.
Guitar Mentor is a flagship product of PlugAI. We research cutting-edge AI models, design agentic systems around them, and ship them inside real products you can hold in your hand. This page is what powers the bot at the bottom of your screen.
The stack
Four pillars under the hood.
PlugAI isn’t a wrapper. It’s an opinionated stack — routing, tools, schema, evolution — designed to keep the chat fast, safe, and useful while the underlying models change every quarter.
Routed inference
PlugAI runs cutting-edge AI models through a smart inference router. We pick the model and the path; you get the latency without ever having to choose.
Agentic tool-calls
Up to 5 tool calls per turn. The model is a controller, not just a transcript — it renders chord cards, suggests plans, deep-links into the app.
Schema-hardened
Strict message schema (50 msgs, 8000 chars each, 32000 total). 60s stream timeout. Per-device daily token cap. Generic upstream-error masking.
Built to evolve
We swap models without breaking your chat. Stream over SSE, persist over MMKV, sync over Firestore when slice E lands. Frontier today; production tomorrow.
PlugAI
Frontier models. Agentic systems. Shipped in production.
The tools
Five tools. One agent.
The chat is just the surface. The agent reaches for these the way a player reaches for a capo. Up to five per turn, schema-validated, streamed.
render_chord_cardInline chord diagram cards rendered straight in the chat surface.
suggest_practice_planPersonalised practice plans built from your weak-spot signals + Leitner schedule.
list_recent_songsPulls from your library + recently played, scoped to the active device.
deep_linkOpens the player, a lesson, the metronome or any screen from a tap in chat.
get_song_chordsReads from the real `AnalysisV1` once the production pipeline lands.
The process
How we ship AI.
Research the frontier
We track every major release across the frontier. We benchmark on the workloads that matter to musicians, not generic eval suites.
Design the agent
We sketch the tool surface first. The model is a controller; the tools are the product. Tools you can compose beat prompts you have to engineer.
Harden the boundary
Strict schemas, generic error masking, per-device caps, server-side audit logs. The model is fast and weird. The boundary is small and boring.
Ship inside a real product
Guitar Mentor is where the stack proves itself. Every PlugAI feature you read about here ships in the app on your phone.
Hardened
Schema-validated. Rate-capped per device.
Fast
SSE streaming. 60-second hard cap per turn.
Composable
Tools you can swap without breaking the chat.
See the rest of PlugAI.
Guitar Mentor is the first product to ship the agentic stack. More are on the way. Follow our work or get in touch.