Case study · live

Yankı — a live Claude product

Kept as a case study, not as this site's identity: it is the clearest evidence that the Claude integration described above is real and running.

You write what happened and how it landed. Yankı names the feeling it hears, quotes your own sentence unchanged, and offers one step for the next hour. It is a companion, not therapy: no diagnosis, no medical advice, no clinical claim.

Try one reflection

This box calls the same endpoint this page describes. It does not store what you type.

Captured answers

Verbatim responses from /api/reflect, not rewritten for the page.

“My manager cancelled our review meeting again and I have been smiling about it all day, but my chest is tight.”

Feeling: anxiety 3
Reflection: You're relieved the meeting is postponed, yet something in your body is signaling worry underneath that smile.
Your words: my chest is tight
Next step: Take three slow, deep breaths and notice what your body needs right now.

anthropic · claude-haiku-4-5-20251001

“I finally finished the thing I kept avoiding and instead of feeling light I just feel flat.”

Feeling: flat 3
Reflection: You pushed through the avoidance and completed it, yet the expected lightness didn't arrive—just emptiness instead.
Your words: I just feel flat
Next step: Take a short walk outside or call someone you trust.

anthropic · claude-haiku-4-5-20251001

How it is built

Anthropic Messages API, model claude-haiku-4-5-20251001, a system prompt that must return a single JSON object.
The server checks the shape. A malformed answer is discarded and the interface says it is unavailable — there is no rule-based fake standing in for the model.
Crisis wording is decided by a fixed word list before the model is called; a match replaces the answer with helpline text.
A quote the model invents is dropped: if the returned quote does not appear verbatim in the user's text, it is not shown.
Nothing is stored on our side during the beta. The waitlist is one key in Cloudflare KV.
Rate limit 6 requests / 60 s per IP, plus a daily budget guard that returns 503 before the balance runs out.

What Yankı is not

Not therapy, not a diagnosis, not a medical device. It has no clinical claim and asks none.
It does not advise on medication, dosage or stopping treatment.
In immediate danger, or thinking of harming yourself: call 112 in Türkiye or your local emergency number. The banner is a rule, not a model judgement.
Sessions train no model, by us or by a vendor. Text goes to Anthropic's API and is retained there only under their API data terms.

Turkish: 112 · English: your local emergency number

API contract

One public endpoint, the same one the demo box above calls. Treat it as a sample integration, not infrastructure.

Method	POST
Path	`/api/reflect`
Request	`{"text": string, "lang": "en"\|"tr"}` — 8–600 characters
Response	`{duygu, siddet, yansitma, alinti, adim, disclaimer, provider, model, cache}`
Errors	`bad_request` 400 · `too_long` 413 · `busy` 429 · `daily_budget` 503 · `upstream` 502
Rate limit	6 requests / 60 s per IP (Durable Object)
Budget	A daily payment-equivalent cap stops the endpoint before the balance runs out
Crisis wording	Decided by a rule list before the model call; the answer is replaced by helpline text

Status

Live: this site, POST /api/reflect, the waitlist with a real deletion path.
Not built yet: accounts, history, reminders. No date committed.
Not started: clinical review of the reflection protocol; no partner signed.