> This page is for version v4 (default).
> For other versions, use one of these documentation indexes:
> - v4 (default): https://help.getzep.com/v4/llms.txt
> - v3: https://help.getzep.com/v3/llms.txt
> - v2: https://help.getzep.com/v2/llms.txt

> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://help.getzep.com/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://help.getzep.com/_mcp/server.

# Lookup user by developer id

POST https://api.getzep.com/api/v4/users/lookup
Content-Type: application/json

Reference: https://help.getzep.com/sdk-reference/user/lookup

## Authentication

- `Authorization` header (required) (prefixed with ` Api-Key  `) — Type "Api-Key" followed by a space and the project API key.

## Request

### Body (application/json)

This endpoint expects a v4.LookupRequest.

- `graph_id` (string, optional) — The developer-assigned graph ID to resolve to a UUID. Mutually exclusive with user_id and thread_id.
- `thread_id` (string, optional) — The developer-assigned thread ID to resolve to a UUID. Mutually exclusive with user_id and graph_id.
- `user_id` (string, optional) — The developer-assigned user ID to resolve to a UUID. Mutually exclusive with thread_id and graph_id.

## Response

### 200

OK

- `created_at` (string, optional) — The time the user was created.
- `disable_default_ontology` (boolean, optional) — When true, disables the use of the default fallback ontology for the user's graph.
- `email` (string, optional) — The email address of the user.
- `first_name` (string, optional) — The first name of the user.
- `graph_uuid` (string, optional) — The unique identifier of the user's graph, populated when the user is created.
- `last_name` (string, optional) — The last name of the user.
- `metadata` (map from string to any, optional) — Arbitrary key-value metadata attached to the user.
- `time_zone` (string, optional) — The user's IANA time zone, used to localize dates in generated context.
- `user_id` (string, optional) — An optional external identity identifier, such as an identity-provider subject claim. Zep uses it to match an identity-provider sign-in to this user. It is not an address; use uuid to address the user in v4. It is unique within the project, can contain at most 500 characters, and cannot be changed after creation. v4 sets it on create; v3 users keep their existing value.
- `uuid` (string, optional) — The unique identifier of the user.

## Errors

### 400 Bad Request Error

Bad Request

- `error` (v4.ErrorBody, optional)

### 401 Unauthorized Error

Unauthorized

- `error` (v4.ErrorBody, optional)

### 404 Not Found Error

Not Found

- `error` (v4.ErrorBody, optional)

## Types

### v4.ErrorBody

- `code` (string, optional)
- `details` (map from string to any, optional)
- `message` (string, optional)
- `param` (string, optional)
- `request_id` (string, optional)

## Examples

**Request**

```json
{}
```

**Response**

```json
{
  "created_at": "string",
  "disable_default_ontology": true,
  "email": "string",
  "first_name": "string",
  "graph_uuid": "string",
  "last_name": "string",
  "metadata": {},
  "time_zone": "string",
  "user_id": "string",
  "uuid": "string"
}
```