# Lossless JSON reconstruction

Build-time release reference. Runtime readiness, deployment, payment settlement and external indexing are not evaluated here. Prices are proposed; this file cannot authorize execution or payment.

WHEN TO USE: Rebuild JSON from json-flatten output without guessing whether numeric keys belong to arrays or objects. Supply scalar values and explicit container types, including the empty root pointer. Rejects leaf/container collisions, missing parents, sparse arrays, unsafe keys, and malformed pointers. Maximum 1,000 combined pointers, 100,000 characters, depth 32.

Release: 0.29.0. Built: 2026-10-06T15:38:00Z.

## Choose for
- Rebuild a document from explicit scalar leaves and container kinds.

## Outside this profile
- Guessing missing parent types or accepting sparse arrays.

Proposed nominal USD 0.005 per successful call; payer fees excluded. No verified runtime availability.

- [Exact release contract](/reference/services/json-unflatten.json)
- [Input schema](/reference/schemas/json-unflatten.input.json)
- [Output schema](/reference/schemas/json-unflatten.output.json)
- [Fixed example](/reference/examples/json-unflatten.json)
- [Complete HTML reference](/discover/tools/json-unflatten)