Rename a tag, or change the value type stored in its slot. Renaming changes the name filters and document reads use; the slot, and every value in it, is untouched. A tag's slot is fixed for its lifetime and each slot holds one kind of value, so fieldType can only change to another type valid for the slot the tag already occupies — anything else is a 400, and the way to get a tag of that type is to create one. A name another tag on this knowledge base already holds is a 409. A workspace API key is rejected with 403; use a personal API key.
/api/v2/knowledge/{knowledgeBaseId}/tags/{tagId}Authorization
apiKey Your Sim API key, personal or workspace-scoped. Generate one under Settings, then API Keys. Operations that reject workspace keys say so in their own description.
In: header
Path Parameters
Unique tag definition identifier.
1 <= lengthUnique knowledge base identifier.
1 <= lengthRequest Body
application/json
Workspace scope and the fields to update. At least one is required.
TypeScript Definitions
Use the request body type in TypeScript.
Response Body
application/json
application/json
application/json
application/json
application/json
application/json
application/json
application/json
application/json
application/json
application/json
curl -X PATCH "https://www.sim.ai/api/v2/knowledge/string/tags/string" \ -H "X-API-Key: YOUR_API_KEY" \ -H "Content-Type: application/json" \ -d '{ "workspaceId": "a91c4b2e-6d3f-4e8a-b5c7-0d9e2f1a8c64", "displayName": "topic" }'{
"data": {
"id": "string",
"displayName": "category",
"tagSlot": "tag1",
"fieldType": "text"
}
}{
"error": {
"code": "BAD_REQUEST",
"message": "Invalid request"
}
}{
"error": {
"code": "UNAUTHORIZED",
"message": "API key required"
}
}{
"error": {
"code": "FORBIDDEN",
"message": "Insufficient workspace permissions",
"details": {
"code": "INSUFFICIENT_WORKSPACE_ROLE"
}
}
}{
"error": {
"code": "NOT_FOUND",
"message": "Not found"
}
}{
"error": {
"code": "CONFLICT",
"message": "Upload has already been completed"
}
}{
"error": {
"code": "PAYLOAD_TOO_LARGE",
"message": "Request body is too large"
}
}{
"error": {
"code": "UNSUPPORTED_MEDIA_TYPE",
"message": "Request body must be sent as application/json"
}
}{
"error": {
"code": "RATE_LIMITED",
"message": "API rate limit exceeded",
"details": {
"retryAfter": "2026-01-01T00:00:30.000Z"
}
}
}{
"error": {
"code": "INTERNAL_ERROR",
"message": "Internal server error"
}
}{
"error": {
"code": "SERVICE_UNAVAILABLE",
"message": "Service temporarily unavailable"
}
}