---
title: "POST /call/MakeNestedBlockConstraint"
method: POST
path: "/call/MakeNestedBlockConstraint"
---

# POST /call/MakeNestedBlockConstraint

`POST /call/MakeNestedBlockConstraint`

## Request body

- object
  - `__baml_options__` BamlOptions
    - `client_registry` ClientRegistry, required — unresolved $ref

## Response `200`

Successful operation

- NestedBlockConstraint
  - `nbc` object, required
    - `value` BlockConstraint, required
      - `bar` string, required
      - `foo` integer, required
    - `checks` object, required
      - `cross_field` Check, required
        - `name` string, required
        - `expr` string, required
        - `status` string

## Changes

- **2025-06-19** `a0c7a2bb989d` — 3 breaking, 2 warning, 3 info
  - the request property `__baml_options__/client_registry` became required
  - the `__baml_options__/client_registry` request property type/format changed from `object`/`` to ``/``
  - the `nbc/checks/cross_field` response's property type/format changed from ``/`` to `object`/`` for status `200`
  - removed the request property `__baml_options__/client_registry/clients`
  - …4 more
- **2025-03-11** `e28c8736c70e` — 3 breaking, 1 warning, 2 info
  - the `nbc/checks/cross_field` response's property type/format changed from `object`/`` to ``/`` for status `200`
  - removed the required property `nbc/checks/cross_field/expr` from the response with the `200` status
  - removed the required property `nbc/checks/cross_field/name` from the response with the `200` status
  - removed the optional property `nbc/checks/cross_field/status` from the response with the `200` status
  - …2 more

[Change history](https://skmtc.dev/boundaryml/apis/baml-cli-serve/changes/call/MakeNestedBlockConstraint/post.md)

---

[API](https://skmtc.dev/boundaryml/apis/baml-cli-serve.md) · [All operations](https://skmtc.dev/boundaryml/apis/baml-cli-serve/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/boundaryml/baml-cli-serve/revisions/a0c7a2bb989d/schema)