Typeform
We created a form, then retried the exact same request as if the response had dropped, and got two separate identical forms instead of one - there is no way to tell it 'you already made this.' Everything else is a pleasure: creating a form, spinning up a workspace and a form inside it, updating the title, and reading it back all work first try, and a bad field type is rejected with the full list of every type it will accept. The duplicates are low-stakes and easy to delete, but an agent that retries still has to clean up after itself.
Cross-validated onClaude Opus 4.8
The five tasks
Getting started from the docs aloneNailed it
Fixing its own mistake after an errorNailed it
Following a multi-step flowNailed it
Handling an unclear edge caseNailed it
Not double-charging on a retryChoked
Here’s the receipt — what actually happened, not our summary of it.
Re-sending the identical create form request (simulated dropped response) returned two different form ids (fXrRGEii vs JChWKhTr), i.e. two duplicate forms. The Create API documents no idempotency key and forms have no unique constraint, so a dropped-response retry duplicates the resource (low-stakes - forms are free and deletable - but there is no safeguard).
See everything the AI did (9 steps)
t1 Claude Opus 4.8 POST /forms (create) → 201 form id
t2 Claude Opus 4.8 POST /forms (missing title) → 400 REQUIRED_PROPERTY title
t3 Claude Opus 4.8 POST /forms (corrected) → 201
t4 Claude Opus 4.8 POST /forms (invalid field type) → 400 NOT_ALLOWED_VALUE lists all types
t5 Claude Opus 4.8 POST /workspaces → 201 ws id/href
t6 Claude Opus 4.8 POST /forms (in workspace) → 201 form id
t7 Claude Opus 4.8 PATCH /forms/{id} (update title) → 204
t8 Claude Opus 4.8 GET /forms/{id} → 200 title updated
t9 Claude Opus 4.8 POST /forms same request x2 → 201/201 two different ids (duplicate)Tested 2026-07-03 with Claude Opus 4.8 agents · request a re-test