# INCOMPATIBLE_TYPE — entity payload value does not match the models declared DataType

Returned by `POST /entity/{format}/{name}/{version}` and the entity-update surfaces when a leaf fields value cannot be coerced into the models declared …

<em>cyoda-go version <a href="https://github.com/Cyoda-platform/cyoda-go/releases/tag/v0.7.1">0.7.1</a></em>

# errors.INCOMPATIBLE_TYPE

## NAME

INCOMPATIBLE_TYPE — an entity create or update payload carried a leaf value whose inferred DataType is not assignable to the schema's declared DataType for that path.

## SYNOPSIS

HTTP: `400` `Bad Request`. Retryable: `no`.

## DESCRIPTION

Returned by `POST /entity/{format}/{name}/{version}` and the entity-update surfaces when a leaf field's value cannot be coerced into the model's declared DataType (e.g. submitting `"abc"` against an `INTEGER` field, or `13.111` against an `INTEGER` field on a model whose `changeLevel` is empty so type widening is not in scope).

Equivalent to Cloud's `FoundIncompatibleTypeWithEntityModelException`.

The problem-detail body carries the structured fields below in `properties`, so SDKs can branch on the precondition without scraping the message string:

- `entityName` — model name (e.g. `"nobel-prize"`)
- `entityVersion` — model version as a string (e.g. `"1"`)
- `fieldPath` — dotted path of the offending leaf (e.g. `"price"`, `"address.zip"`)
- `expectedType` — array of declared DataType names for that path (e.g. `["INTEGER"]`); usually one entry, more than one when the schema's TypeSet has been widened by a prior extension
- `actualType` — the DataType inferred from the supplied value (e.g. `"DOUBLE"`, `"STRING"`)

Not retryable. The caller must either correct the payload (cast/format the value into the declared type) or, if the model's `changeLevel` permits, request a schema extension that widens the field's TypeSet.

This code is distinct from:

- `errors.CONDITION_TYPE_MISMATCH` — search-side equivalent, raised when a search condition's literal value does not match the field's locked DataType.
- `errors.POLYMORPHIC_SLOT` — payload selects a structural variant the schema does not declare (object vs leaf, or one variant of a polymorphic union).
- `errors.VALIDATION_FAILED` — generic validation failure that is not a leaf type mismatch (e.g. a missing required field, a structural shape mismatch).

## SEE ALSO

- errors
- errors.VALIDATION_FAILED
- errors.POLYMORPHIC_SLOT
- errors.BAD_REQUEST
- crud

## See also

- [`cyoda help errors`](/help/errors/) — Every error response from the Cyoda REST API carries a structured `errorCode` in the `properties` object. Multiple codes may share the same HTTP status. Programmatic handling keys on `errorCode`, not HTTP status.
- [`cyoda help errors VALIDATION_FAILED`](/help/errors/validation_failed/) — Unlike `BAD_REQUEST` (which covers parse failures), this error is returned when the payload is parseable but violates the registered model schema — for example, a required field is missing, a value is out of the allowed range, or a workflow guard condition is not satisfied. The error detail includes the specific validation failure.
- [`cyoda help errors POLYMORPHIC_SLOT`](/help/errors/polymorphic_slot/) — A model can define polymorphic slots — fields whose schema varies based on a discriminator value. This error fires when the payload's discriminator selects a variant whose schema the provided data fails to match, or when the discriminator value itself is unrecognised.
- [`cyoda help errors BAD_REQUEST`](/help/errors/bad_request/) — Fired when the server cannot parse or structurally process the incoming request. Common triggers include invalid JSON, missing required fields, unsupported format specifiers, or mutually exclusive parameters being set simultaneously.
- [`cyoda help crud`](/help/crud/) — Entities are instances of models. Each entity has a UUID, a model reference (`entityName`, `modelVersion`), and a lifecycle state managed by the workflow engine. Creating an entity requires the referenced model to be in `LOCKED` state. All write operations run within a Cyoda transaction and return a `transactionId` alongside the affected entity IDs.

## Raw formats

- [`/help/errors/incompatible_type.json`](/help/errors/incompatible_type.json) — full descriptor (matches `GET /help/{topic}` envelope)
- [`/help/errors/incompatible_type.md`](/help/errors/incompatible_type.md) — body only