> ## Documentation Index
> Fetch the complete documentation index at: https://docs.praxa.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Lexically query one subject's candidates

> Run bounded lexical search over one subject's isolated Praxa memory candidates with provider and record-kind filters.

Run bounded lexical search over one subject's isolated Praxa memory candidates with provider and record-kind filters.

<Info>
  **Availability:** Qualification preview. **Required scope:** `memory:read`.
</Info>

## Authenticate safely

Create a disposable **personal workspace** API key with exactly `memory:read`. Send it as `Authorization: Bearer $PRAXA_API_KEY`. A Gateway OAuth token, Supabase JWT, provider credential, or organization memory key is not interchangeable with this key.

The hosted playground sends the credential from your browser session to the documented API through the configured playground proxy. Use test data, never share the key, and revoke it when the check ends.

## Request fields

<ParamField body="apiVersion" type="v1" required>
  apiVersion request field.
</ParamField>

<ParamField body="subject" type="string" required>
  subject request field.
</ParamField>

<ParamField body="query" type="string" required>
  query request field.
</ParamField>

<ParamField body="providerIds" type="array<mem0 | zep | graphiti | langgraph | letta | openai_agents | custom>">
  providerIds request field.
</ParamField>

<ParamField body="kinds" type="array<message | fact | summary | episode | pinned_context | document | entity | edge>">
  kinds request field.
</ParamField>

<ParamField body="limit" type="integer">
  limit request field.
</ParamField>

## Runnable request examples

<CodeGroup>
  ```bash cURL theme={null}
  curl --fail-with-body -X POST 'https://api.praxa.io/v1/memory/query' \
    -H "Authorization: Bearer $PRAXA_API_KEY" \
    -H "Content-Type: application/json" \
    --data '{
    "apiVersion": "v1",
    "subject": "customer-42",
    "query": "weekly summaries",
    "providerIds": [
      "custom"
    ],
    "kinds": [
      "fact"
    ],
    "limit": 20
  }'
  ```

  ```javascript Node.js theme={null}
  const response = await fetch("https://api.praxa.io/v1/memory/query", {
    "method": "POST",
    "headers": {
      "Authorization": `Bearer ${process.env.PRAXA_API_KEY}`,
      "Content-Type": "application/json"
    },
    "body": JSON.stringify({
      "apiVersion": "v1",
      "subject": "customer-42",
      "query": "weekly summaries",
      "providerIds": [
        "custom"
      ],
      "kinds": [
        "fact"
      ],
      "limit": 20
    })
  });
  const text = await response.text();
  if (!response.ok) throw new Error(`${response.status}: ${text}`);
  console.log(text ? JSON.parse(text) : { status: response.status });
  ```

  ```python Python theme={null}
  import json
  import os
  from urllib import error, request

  payload = json.dumps({
    "apiVersion": "v1",
    "subject": "customer-42",
    "query": "weekly summaries",
    "providerIds": [
      "custom"
    ],
    "kinds": [
      "fact"
    ],
    "limit": 20
  }).encode()

  req = request.Request(
      "https://api.praxa.io/v1/memory/query",
      method="POST",
      headers={
        "Authorization": f"Bearer {os.environ['PRAXA_API_KEY']}",
        "Content-Type": "application/json"
      },
      data=payload,
  )
  try:
      with request.urlopen(req, timeout=30) as response:
          text = response.read().decode()
          print(json.loads(text) if text else {"status": response.status})
  except error.HTTPError as exc:
      raise RuntimeError(f"{exc.code}: {exc.read().decode()}") from exc
  ```
</CodeGroup>

## What success means

A `200` response contains subject-scoped lexical matches. It is not vector, semantic, or graph recall.

## Successful response

**200** — Bounded lexical matches for the requested subject.

<ResponseField name="apiVersion" type="v1" required>
  apiVersion response field.
</ResponseField>

<ResponseField name="retrievalMode" type="lexical" required>
  retrievalMode response field.
</ResponseField>

<ResponseField name="data" type="array<object>" required>
  data response field.
</ResponseField>

<ResponseExample>
  ```json 200 theme={null}
  {
    "apiVersion": "v1",
    "retrievalMode": "lexical",
    "data": [
      {
        "lexicalRank": 0,
        "candidate": {
          "id": "018f0000-0000-7000-8000-000000000001",
          "state": "candidate",
          "contentDigest": "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
          "createdAt": "2026-08-13T12:00:00.000Z",
          "record": {
            "apiVersion": "v1",
            "providerId": "mem0",
            "sourceId": "example",
            "externalRecordId": "example",
            "revision": "example",
            "kind": "message",
            "subject": "example",
            "visibility": "subject",
            "content": "example",
            "provenance": "example",
            "occurredAt": "example",
            "observedAt": "example"
          }
        }
      }
    ]
  }
  ```
</ResponseExample>

## Handle failures

| Response                    | Meaning                                                             | Safe action                                                                         |
| --------------------------- | ------------------------------------------------------------------- | ----------------------------------------------------------------------------------- |
| `400 invalid_request`       | The method, path, headers, query, or body failed strict validation. | Correct the request; do not retry unchanged input.                                  |
| `401 authentication_failed` | The bearer key is missing, malformed, expired, or revoked.          | Stop and replace the key through the authenticated console.                         |
| `403 authorization_failed`  | The authenticated key lacks scope or tenant authority.              | Request only the missing least-privilege scope; never substitute another tenant ID. |
| `429 rate_limited`          | The principal exceeded a bounded rate.                              | Honor `retryAfterMs` or `Retry-After`, add jitter, and cap attempts.                |
| retryable `5xx`             | The server could not confirm a final response.                      | Reconcile reads or replay the exact keyed mutation before creating new work.        |

```json Example problem theme={null}
{
  "type": "https://docs.praxa.io/problems/authorization-failed",
  "title": "Authorization failed",
  "status": 403,
  "code": "authorization_failed",
  "detail": "The API key does not grant the required scope.",
  "retryable": false
}
```

## Verify the result

1. Require `retrievalMode: "lexical"`.
2. Confirm every result matches the requested subject and filters.
3. Query a second subject and tenant and require isolation.

## Retry, cleanup, and production use

* Treat `401`, `403`, and `409` as authority or state signals, not generic retry prompts.
* For `429` or retryable 5xx responses, follow server retry guidance and keep a bounded attempt budget.
* Move the request into a trusted application backend before production; never ship the Praxa key in browser or mobile code.
* Revoke the disposable key, disable test webhooks, and erase disposable candidate data after validation.

Continue with [API authentication](/api-playground/authentication), the [failure and retry guide](/api-playground/errors), and the [end-to-end coverage matrix](/api-playground/coverage-and-testing).