Prices run from a tenth of a cent for a biomarker sync to eight tenths for a lab panel, published per skill rather than hidden in a plan, which makes the cost of an agent loop predictable before you write it. The dependency worth understanding first is the phone: the account and the wearable data both come from the iOS app, so an agent-only setup reaches the chat, lab and food skills but not the CGM ones. The shipped routing file is a nice touch — it lets an agent choose the right skill without you enumerating them in a prompt.
An interface to Sally, A1C's metabolic-health service. Seven skills are exposed as tools, each priced per call against a wallet balance, reading the data the A1C Insights iPhone app collects through HealthKit. The same skills are reachable over REST for anything that cannot speak MCP.
- 64+ live biomarkers pulled from wearables and CGM into the agent's context — 10 calls free each month, then $0.001 each (health_sync).
- A full CGM snapshot at $0.005 a call: time in range, variability and postprandial curves (metabolic_overview).
- Lab panels parsed and interpreted at $0.008 a call, with risk flags and reference ranges attached (analyze_lab_result).
- Meals graded by macros and predicted glucose response at $0.004 a call, with patterns surfaced across entries (food_journal).
- Morning, afternoon and evening readouts assembled from sleep, vitals and activity at $0.003 a call (health_insights).
- A supplement stack graded for interactions, evidence quality and gaps at $0.008 a call (supplement_grading).
- Open questions answered across preventive health and Traditional Chinese Medicine, evidence-graded, at $0.003 a call (chat_with_sally).
- A routing file you can drop into an agent's system prompt so it picks the right skill on its own, with decision tables, chaining patterns and anti-patterns.
An A1C account, which is created in the A1C Insights iPhone app — the account itself cannot be made anywhere else. Then an API key minted at console.a1c.io, in the sk-sally- form, shown once. Each key is bound to one account; several keys can share one wallet balance, and per-key usage stays auditable. Three skills read CGM and wearable data collected through HealthKit, so they depend on the phone app having that data; the chat, lab and food-journal skills work without any wearable. Calls draw on a funded wallet at the per-call prices above.
