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Documentation Index

Fetch the complete documentation index at: https://isaree-cd4b6397.mintlify.app/llms.txt

Use this file to discover all available pages before exploring further.

The Primary Agent is the agent you talk to in Patient Chat — every Patient Chat is a conversation between you and the Primary Agent, about the patient. The Primary Agent interprets what you say, calls Agents and MCP Servers, and produces the response. You have to pick a Primary Agent before you can open a Patient Chat. The Primary Agent does not operate in Workspace — Workspace lets you chat directly with an Agent. This page covers two things: the model behind the Primary Agent, and its system prompt.

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Open the Primary Agent Model picker

Open Settings in Isa, then open Primary Agent Model. The picker has three parts:
  • IN USE at the top — the active variant, with size, capabilities, and where it runs (on-device or cloud).
  • Thinking Mode toggle — for models that support step-by-step reasoning.
  • Model Families — grouped by maker (Qwen 3.5, Liquid 2.5, Gemma 3, Llama 3.2, Qwen 3) for on-device, plus OpenAI and Aki.io for cloud. A green dot marks the family the active variant comes from.

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Pick on-device or cloud

The first decision is where the model runs:
  • On-device — the model runs on your iPhone or iPad. What the Primary Agent processes — the chat, transcripts, OCR text — never leaves your device. Restricted to models small enough to fit in RAM.
  • Cloud — the model runs via OpenAI or Aki.io. The conversation leaves your device when it does. You bring your own API key.
See On-device vs. cloud for the deeper trade-off, and Data and privacy for what data flows where.
The Primary Agent and any Agent you invoke share your device’s RAM. Pick a Primary Agent small enough to leave room for the Agents you actually use.

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Pick an on-device Primary Agent

The on-device families are pre-vetted lists of open-weight models that run on Apple hardware. Open a family to see its variants. Each variant lists size in GB, capabilities (Vision, Thinking), and the iPhone it’s tested on. Solid defaults for clinical use:
  • Qwen 3.5 (4B) — careful and thorough for longer histories, nuanced summaries, and busy documents. Best on iPhone 16 Pro / 17 Pro.
  • Qwen 3.5 (2B) — everyday default for visit summaries, referrals, and lab-photo extraction. Best on iPhone 15 Pro / 16 / 17.
  • LFM 2.5 Thinking (1.2B) (Liquid 2.5 family) — small reasoning model for tool-heavy workflows when you need to leave room for Agents.
Download a variant to install it. Once it’s installed, select it to make it active. Variants you’ve downloaded show Delete instead. For deeper sizing guidance, see Choose a model.

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Pick a cloud Primary Agent

OpenAI and Aki.io are families inside the picker. Open one and you’ll see:
  • API key at the top — paste your key and save it. The key stays on your device. Once saved, the family shows an “API key saved” badge with the last four characters.
  • Variants below — pick one to make it active. There’s nothing to download.
Two cloud providers:
  • OpenAI — OpenAI’s proprietary models.
  • Aki.io — hosts open-weight models (Llama 3.3 70B, Qwen 3.6 35B, Gemma 4 26B, GPT-OSS 120B, MiniMax M2.5 230B) on EU infrastructure and uses the same API format as OpenAI. Cheaper than OpenAI.

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Switch between models

To change the active Primary Agent, open the picker and pick any other variant — on-device or cloud, in any family. The new variant becomes active immediately and the IN USE panel updates. API keys and downloaded models stay in place, so switching back is a single tap.

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Turn on Thinking Mode

The Thinking Mode toggle at the top of the picker lets compatible models reason step-by-step before answering. Models that support it carry a Thinking badge. Thinking Mode improves accuracy on complex questions but slows responses. It can also reduce reliability when the Primary Agent is calling MCP Servers or other Agents — turn it off if you’re running tool-heavy workflows and seeing flaky behavior. A handful of variants (like Qwen 3 Thinking (4B)) are always-thinking regardless of the toggle.

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Edit the system prompt

The system prompt tells the Primary Agent how to behave in Patient Chat — its tone, and what it should and shouldn’t do. Open it from Settings → System Prompt. An Agent’s system prompt and the Primary Agent’s system prompt do different jobs. An Agent’s prompt is narrow — it describes the one task that Agent is built for (summarise a visit, extract labs, draft a referral). The Primary Agent’s prompt is broader — it sets the tone, ground rules, and response style across every Patient Chat.
Changing the system prompt changes how the Primary Agent behaves in every Patient Chat conversation. Edit carefully — if you’re unsure, ask in Discord.

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Know what else this affects

The model you pick has consequences elsewhere in Isa:
  • Where the Primary Agent’s data goes. An on-device variant keeps the chat, OCR text, and Scribe transcripts the Primary Agent sees on the device. A cloud variant sends them to the provider. This setting only governs the Primary Agent — cloud Scribe Agents and external MCP Servers still send their own data off-device regardless of which Primary Agent you pick.
  • Camera is VLM-only. The Camera button in Patient Chat only appears when the active variant is a VLM (carries the Vision badge). OCR via Scan Doc works either way.
  • Scribe Agent extraction. When the Extraction provider in Settings is set to On-Device, it uses the Primary Agent’s loaded model. If the Primary Agent’s model is cloud, extraction also goes off-device — independently of the Scribe Agent’s own Transcription setting.

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Next

Choose a model

Size the Primary Agent for the device — parameter count, quantization, RAM headroom.

Data and privacy

What stays on-device versus what leaves it.

Patient Chat

The main surface where the Primary Agent does its work.