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

Records a fact in a space (`relate`). A fact that contradicts a current one with the same subject and a single-valued predicate closes the older fact; nothing is overwritten.

**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/spaces/space/relations`
- **Scope** `knowledge:write`
- **Effect** `write` — a successful call changes state.
- **Collection** [relations](/docs/api/relations)
- **Query** `relation_id`, `validate_only`

## Request

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

### Relation

| Field | Type | What it is |
| --- | --- | --- |
| `name` | `string` | `orgs/{org}/projects/{project}/envs/{env}/spaces/{space}/relations/{relation}`. |
| `meta` | `ResourceMeta` | Resource metadata. |
| `subject` | `string` | The entity the fact is about. Required. |
| `predicate` | `string` | The relation type, snake_case, for example `works_at` or `prefers`; a core predicate or one of an accepted Knowledge Schema. Required. |
| `object` | `string` | The other entity, for an edge. A fact has `object`, `value`, or both. |
| `value` | `value` | The value, for a fact about one entity. |
| `statement` | `string` | The fact as one sentence, used for search and shown with citations. |
| `valid_start_time` | `timestamp` | When the fact starts to hold in the world; default when it was recorded. |
| `valid_end_time` | `timestamp` | When the fact stopped holding in the world; unset while it holds. |
| `episodes` | `string[]` | The episodes the fact comes from. A structured write with none records its own episode and cites it; an extracted fact cites the episodes it was read from. |

### 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. |

## Response

| Field | Type | What it is |
| --- | --- | --- |
| `name` | `string` | `orgs/{org}/projects/{project}/envs/{env}/spaces/{space}/relations/{relation}`. |
| `uid` | `string` | `krel_<26 base32>`; never reused. Output only. |
| `meta` | `ResourceMeta` | Resource metadata. |
| `subject` | `string` | The entity the fact is about. Required. |
| `predicate` | `string` | The relation type, snake_case, for example `works_at` or `prefers`; a core predicate or one of an accepted Knowledge Schema. Required. |
| `object` | `string` | The other entity, for an edge. A fact has `object`, `value`, or both. |
| `value` | `value` | The value, for a fact about one entity. |
| `statement` | `string` | The fact as one sentence, used for search and shown with citations. |
| `valid_start_time` | `timestamp` | When the fact starts to hold in the world; default when it was recorded. |
| `valid_end_time` | `timestamp` | When the fact stopped holding in the world; unset while it holds. |
| `episodes` | `string[]` | The episodes the fact comes from. A structured write with none records its own episode and cites it; an extracted fact cites the episodes it was read from. |
| `provenance` | `Provenance` | Where it came from and who wrote it. Output only. |
| `successor` | `string` | The fact that replaced this one, once it is superseded. Output only. |
| `create_time` | `timestamp` | When the fact was recorded. Output only. |
| `supersede_time` | `timestamp` | When the fact was replaced by a newer record; unset while current. 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. |

### 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/spaces/space/relations" \
  -H "Authorization: Bearer $SYLPHX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"predicate":"…","subject":"…"}'
```

**TypeScript**

```ts
const response = await sylphx.knowledge.relations.create({ parent: 'orgs/acme/projects/shop/envs/production/spaces/space', relation: { predicate: '…', subject: '…' } })
```

**Rust**

```rust
let mut req = sylphx::knowledge::CreateRelationRequest::default();
req.parent = "orgs/acme/projects/shop/envs/production/spaces/space".to_string();
req.relation = Some(sylphx::knowledge::Relation {
    predicate: "…".to_string(),
    subject: "…".to_string(),
    ..Default::default()
});
let response = sx.knowledge().relations().create(req).await?;
```

**CLI**

```bash
sylphx knowledge relations create --parent orgs/acme/projects/shop/envs/production/spaces/space --subject … --predicate …
```

**MCP**

```json
{ "method_id": "knowledge.relations.create", "args": {"parent":"orgs/acme/projects/shop/envs/production/spaces/space","relation":{"predicate":"…","subject":"…"}} }
```