| bc-version |
domain |
keywords |
technologies |
countries |
application-area |
|
|
mcp |
| api-page |
| key-fields |
| editable |
| insert |
| odata |
|
|
|
|
CURABIS MCP: ODataKeyFields Editability Rule
Description
Key fields declared in ODataKeyFields cannot have Editable = false when the API page permits inserts and the field is consumer-provided. This restriction causes the OData layer to reject the field as an unknown property during POST operations.
Why It Matters
When a field is marked read-only, Business Central removes it from the OData write schema. If a consumer attempts to POST a new record with that key field in the request body, the system cannot match it to any writable property and returns a BadRequest error.
Problematic vs. Correct Approach
Incorrect:
field(projectNo; Rec."Project No.")
{
Editable = false; // prevents API inserts when consumer must supply the value
}
Correct:
field(projectNo; Rec."Project No.")
{
// No Editable = false — consumer supplies this on POST
}
Key Takeaways
- Every consumer-provided field referenced in
ODataKeyFields on pages where InsertAllowed = true must remain editable
- The OData specification itself enforces immutability of key fields post-creation — no additional markup required
- Non-key fields can still use
Editable = false without triggering this issue
- Test create operations via your OData endpoint to verify compliance
BCApps Reference
BCApps BCPTSuiteAPI.Page.al uses ODataKeyFields = SystemId with SystemId marked Editable = false. This is a valid exception — SystemId is a system-generated GUID that BC assigns automatically on insert. The consumer never provides it in a POST body, so marking it non-editable does not break API inserts.
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