Unsay — clinician write screen

Server, read token, signing key

Unsay server Where /mcp and /write live. Defaults to this page’s own origin when it is served over http. Read token — Bearer, scope care.read.user This screen reads the plan over MCP like any other host: initialize, resources/list, resources/read. There is no private API behind it, so it needs the same token an assistant would present. Write key — HMAC secret The secret the server was started with (UNSAY_WRITE_SECRET). Used to compute HMAC-SHA256 over timestamp + "." + body — the timestamp is inside the MAC, so a captured request cannot be replayed. Held in sessionStorage for this tab only; never sent, never hardcoded.

Current plan

What this screen sends

One request. The body is signed exactly as it is transmitted — the MAC covers the byte string, not a re-serialisation of a parsed object, because that difference is how signed webhooks get forged.

POST {server}/write
Content-Type: application/json
X-Unsay-Timestamp: 2026-10-08T09:14:22.418Z
X-Unsay-Signature: <hex HMAC-SHA256( timestamp + "." + body , write secret )>

{"patient":"ray","domain":"weight_bearing","audience":"user","value":"…",
 "authorId":"okafor","authorLabel":"Sarah Okafor, physio","priority":0.9}

Serve this page from the server’s own origin. The Unsay server sends no CORS headers and answers a preflight with 405, so a browser blocks every request above before it leaves when this page is opened from file:// or a different port. From the same origin it needs nothing.

writtenAt is not in the body on purpose: the server stamps it from its own clock. A writer that could set it could backdate a correction, and “how old is this instruction” is something the assistant says out loud.

See the mechanism on the landing page, or watch the correction land on the Echo Show screen.

Unsay relays what a clinician wrote. It does not generate clinical guidance and is not a medical device. Ray Dunn, Sarah Okafor and this care plan are a scenario; the seed record is committed at src/seed.ts.

Ray Dunn · post-op day 5

Current plan

What this screen sends