---
# @generated by sylphx-gen 0.1.0 from contracts@fb95f0c42a0ec5d8e3cb694c0054b529c0b24b184112c65ef60c9044b4ce61f9. Do not edit.
title: "Create an entity"
description: "`knowledge.entities.create` (POST /v1/{parent}/entities): Creates an entity in a space."
type: reference
product: knowledge
summary: "Creates an entity in a space."
updated: 2026-09-28
nav: false
---

Creates an entity in a space. An entity whose external id already names one in the graph is refused with `RESOURCE_ALREADY_EXISTS`, which names it; use Update with `allow_missing` to upsert.

**Not available yet.** Sylphx Knowledge is declared in the registry but no backend serves it: every call answers `501` with the problem code `UNIMPLEMENTED`.

- **Path** `POST https://api.sylphx.com/v1/orgs/acme/projects/shop/envs/production/entities`
- **Scope** `knowledge:write`
- **Effect** `write` — a successful call changes state.
- **Collection** [entities](/docs/api/entities)
- **Query** `entity_id`, `validate_only`

## Request

| Field | Type | What it is |
| --- | --- | --- |
| `parent` | `string` | The parent to create in. Required. |
| `entity_id` | `string` | The entity id, the final name segment; the server assigns one when empty. |
| `entity` | `Entity` | The entity to create; only caller-writable fields are read. Required. |
| `validate_only` | `bool` | Validate and return the result without writing anything. |

### Entity

| Field | Type | What it is |
| --- | --- | --- |
| `name` | `string` | `orgs/{org}/projects/{project}/envs/{env}/entities/{entity}`. |
| `meta` | `ResourceMeta` | Resource metadata. |
| `entity_type` | `string` | The type: a core type (`person`, `organisation`, `customer`, `contact`, `product`, `project`, `document`, `decision`, `playbook`, `case`, `topic`) or a type of an accepted Knowledge Schema, `<schema>.<type>`. Required. |
| `title` | `string` | The name people use for it. Required. |
| `aliases` | `string[]` | Other names it is known by; at most 50. |
| `properties` | `struct` | Properties, valid against the type's JSON Schema. |
| `external_ids` | `ExternalId[]` | Identifiers in other systems. Two writes with the same external id in one graph are the same entity (deterministic resolution). At most 50. |
| `space` | `string` | The space the entity was first stated in. Required. |

### ResourceMeta

| Field | Type | What it is |
| --- | --- | --- |
| `labels` | `map<string, string>` | Caller-writable, indexed labels (AIP-122 label rules). |
| `annotations` | `map<string, string>` | Caller-writable, unindexed annotations. |
| `display_name` | `string` | Caller-writable human-readable name. |

### ExternalId

| Field | Type | What it is |
| --- | --- | --- |
| `kind` | `string` | The kind of identifier: `email`, `phone`, `auth_subject`, `channel_user`, `account`, or a caller's own kind. Required. |
| `value` | `string` | The identifier, normalised (a lowercase email, an E.164 phone number). Required. |

## Response

| Field | Type | What it is |
| --- | --- | --- |
| `name` | `string` | `orgs/{org}/projects/{project}/envs/{env}/entities/{entity}`. |
| `uid` | `string` | `ken_<26 base32>`; never reused. Output only. |
| `meta` | `ResourceMeta` | Resource metadata. |
| `entity_type` | `string` | The type: a core type (`person`, `organisation`, `customer`, `contact`, `product`, `project`, `document`, `decision`, `playbook`, `case`, `topic`) or a type of an accepted Knowledge Schema, `<schema>.<type>`. Required. |
| `title` | `string` | The name people use for it. Required. |
| `aliases` | `string[]` | Other names it is known by; at most 50. |
| `properties` | `struct` | Properties, valid against the type's JSON Schema. |
| `external_ids` | `ExternalId[]` | Identifiers in other systems. Two writes with the same external id in one graph are the same entity (deterministic resolution). At most 50. |
| `space` | `string` | The space the entity was first stated in. Required. |
| `provenance` | `Provenance` | Where it came from and who wrote it. Output only. |
| `lifecycle` | `EntityLifecycle` | Whether the entity stands on its own or was merged into another. Output only. One of `active`, `merged`. |
| `survivor` | `string` | The entity this one was merged into, while `lifecycle` is `ENTITY_LIFECYCLE_MERGED`. Output only. |
| `merged_entities` | `string[]` | The entities merged into this one; each can be split back out. Output only. |
| `create_time` | `timestamp` | When the entity was first recorded. Output only. |
| `update_time` | `timestamp` | When the entity last changed. Output only. |

### ResourceMeta

| Field | Type | What it is |
| --- | --- | --- |
| `generation` | `int64` | Increases by one on every change to `spec`. Output only. |
| `etag` | `string` | Strong ETag (AIP-154): changes on any change to spec, status, or metadata. Send it back as `If-Match` or `etag` to make Update and Delete conditional; a mismatch fails with ABORTED / 409 `ETAG_MISMATCH`. Output only. |
| `create_time` | `timestamp` | When the Resource was created. Output only. |
| `update_time` | `timestamp` | When the Resource last changed. Output only. |
| `delete_time` | `timestamp` | Set while the Resource is being deleted. Output only. |
| `labels` | `map<string, string>` | Caller-writable, indexed labels (AIP-122 label rules). |
| `annotations` | `map<string, string>` | Caller-writable, unindexed annotations. |
| `display_name` | `string` | Caller-writable human-readable name. |
| `creator` | `string` | The principal that created the Resource. Output only. |

### ExternalId

| Field | Type | What it is |
| --- | --- | --- |
| `kind` | `string` | The kind of identifier: `email`, `phone`, `auth_subject`, `channel_user`, `account`, or a caller's own kind. Required. |
| `value` | `string` | The identifier, normalised (a lowercase email, an E.164 phone number). Required. |

### Provenance

| Field | Type | What it is |
| --- | --- | --- |
| `principal` | `string` | The principal the write is attributed to, as a share subject (`user:<id>`, `end_user:<id>`): the member or end user an agent or app acts for. Set by the server from the caller's credential. Output only. |
| `actor` | `string` | The caller that made the write when it is not the principal: an agent (`agent:<id>`), an app key (`api_key:<id>`) or a connector. Output only. |
| `channel` | `Channel` | The path the write took. Output only. One of `api`, `tool`, `import`, `extraction`. |
| `method` | `SourceMethod` | How the content was produced; default `SOURCE_METHOD_STATED`. Only the service writes `SOURCE_METHOD_EXTRACTED`. One of `stated`, `extracted`, `imported`. |
| `references` | `SourceRef[]` | References to where the content came from: a run and step, a work item, a message, a URL. At most 20. |
| `model` | `string` | For an extracted record, the model id that extracted it. Output only. |
| `confidence` | `double` | For an extracted record, the extractor's confidence, 0 to 1. Output only. |

### SourceRef

| Field | Type | What it is |
| --- | --- | --- |
| `uri` | `string` | A URI: a URL, or a URN of a platform record such as a Workflows run step. Required. |
| `label` | `string` | A short label to show with a citation. |

## Errors

- [`UNAUTHENTICATED`](/docs/api/errors/UNAUTHENTICATED) — No valid key or token was presented.
- [`PERMISSION_DENIED`](/docs/api/errors/PERMISSION_DENIED) — The key lacks the method's permission.
- [`UNKNOWN_FIELD`](/docs/api/errors/UNKNOWN_FIELD) — The request has a field the schema does not know.
- [`INVALID_FIELD`](/docs/api/errors/INVALID_FIELD) — A field failed validation.
- [`RESOURCE_ALREADY_EXISTS`](/docs/api/errors/RESOURCE_ALREADY_EXISTS) — A Resource with this name exists.
- [`IDEMPOTENCY_KEY_REUSED`](/docs/api/errors/IDEMPOTENCY_KEY_REUSED) — An Idempotency-Key was reused with another body.
- [`IDEMPOTENCY_IN_PROGRESS`](/docs/api/errors/IDEMPOTENCY_IN_PROGRESS) — The first call with this Idempotency-Key is still running.

Every error arrives in the body [Errors](/docs/platform/errors) describes.

## Examples

**cURL**

```curl
curl -X POST "https://api.sylphx.com/v1/orgs/acme/projects/shop/envs/production/entities" \
  -H "Authorization: Bearer $SYLPHX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"entity_type":"…","space":"…","title":"…"}'
```

**TypeScript**

```ts
const response = await sylphx.knowledge.entities.create({ entity: { entityType: '…', space: '…', title: '…' }, parent: 'orgs/acme/projects/shop/envs/production' })
```

**Rust**

```rust
let mut req = sylphx::knowledge::CreateEntityRequest::default();
req.entity = Some(sylphx::knowledge::Entity {
    entity_type: "…".to_string(),
    space: "…".to_string(),
    title: "…".to_string(),
    ..Default::default()
});
req.parent = "orgs/acme/projects/shop/envs/production".to_string();
let response = sx.knowledge().entities().create(req).await?;
```

**CLI**

```bash
sylphx knowledge entities create --parent orgs/acme/projects/shop/envs/production --entity-type … --title … --space …
```

**MCP**

```json
{ "method_id": "knowledge.entities.create", "args": {"entity":{"entity_type":"…","space":"…","title":"…"},"parent":"orgs/acme/projects/shop/envs/production"} }
```