> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs-beta.getzep.com/v4/sdk-reference/user/lookup/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs-beta.getzep.com/_mcp/server.

# Lookup user by developer id

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

Reference: https://docs-beta.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) — The developer-assigned identifier of the user.
- `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"
}
```