> Solana Developer Platform docs, served as Markdown. The [docs index](https://platform.solana.com/docs.md) lists every page and [llms.txt](https://platform.solana.com/docs/ai/llms.txt) the key ones; [SKILL.md](https://platform.solana.com/SKILL.md) has the rules for building on SDP.

# Check signer via simulated memo transaction

Signs a server-authored memo message with the named wallet, verifies the signature, and simulates the transaction.

`POST /v1/wallets/signer-check`

Nothing is broadcast and no sponsorship is spent. The wallet is the only readonly signer and the request cannot supply memo text.

Requires an [API key](/docs/developing-with-sdp/authentication) with the `wallets.execute` action.

## Headers

- **`x-project-id`** · `string` · min length 1 · example `prj_example`

  Required for dashboard sessions. API keys use their assigned project.

- **`Idempotency-Key`** · `string`

  Use a unique 1–255 printable ASCII key per operation. Reuse it with the same request on retries. An in-flight attempt returns `409`; a changed request returns `422`. [Retry and recovery rules](/docs/developing-with-sdp/idempotency).

## Request body

`application/json` · required

walletId is the Provider wallet ID to check, required. Ambiguous Provider IDs are rejected; the check uses the resolved exact custody wallet record, and an API key may check only a wallet within its wallet scope.

- **`walletId`** · `string` · required · min length 1

## Responses

- **`200`** Signer check verified in simulation

  - **`data`** · `object` · required

    Signer check response payload.

    - **`walletId`** · `string` · required · min length 1 · example `privy_wallet_123`

      Resolved signing wallet ID.

    - **`walletAddress`** · `string` · required · min length 32 · max length 44 · example `So11111111111111111111111111111111111111112`

      Resolved signer address used for the check message.

    - **`feePayer`** · `string` · required · min length 32 · max length 44 · example `So11111111111111111111111111111111111111112`

      Funded fee payer address used in the simulated message; nothing is spent from it.

    - **`memo`** · `string` · required · example `SDP signer check 123e4567-e89b-42d3-a456-426614174000`

      Server-generated memo text in the simulated check message.

    - **`signature`** · `string` · required · example `sig_example`

      The custody wallet's Ed25519 signature over the check message, base58. Verified server-side and exercised in RPC simulation only — the check never broadcasts, so this signature does not exist on chain.

    - **`simulated`** · `boolean` · required · always `true`

      Always true: signer checks run in simulation and cannot spend sponsorship.

    - **`checkedAt`** · `string` · required · format `date-time` · example `2026-02-20T00:00:00.000Z`

      Timestamp recorded after the simulation succeeded.

  - **`meta`** · `object` · required

    Response metadata.

    - **`requestId`** · `string` · required · min length 1 · example `req_example`

      Request identifier for tracing.

    - **`timestamp`** · `string` · required · format `date-time` · example `2025-01-01T00:00:00.000Z`

      ISO 8601 timestamp.

- **`400`** Bad Request

  - **`error`** · `object` · required

    Standard error payload.

    - **`code`** · `string` · required

      Machine-readable error code.

    - **`message`** · `string` · required

      Human-readable error message.

    - **`details`** · `object`

      Optional error details for debugging.

      - **`*`** · `any`

  - **`meta`** · `object`

    - **`requestId`** · `string` · min length 1 · example `req_example`

      Request identifier for tracing.

- **`401`** Unauthorized

  Same fields as `400`.

- **`403`** Forbidden. Requires the `wallets.execute` action: an API key must hold it (a module's `manage` or `execute` also covers its `read`), and a signed-in member's organization role must include it. Without it the error is INSUFFICIENT_PERMISSIONS and `error.details.action` names the action. Any other 403 names its own reason.

  Same fields as `400`.

- **`404`** Not Found

  Same fields as `400`.

- **`409`** Conflict

  Same fields as `400`.

- **`422`** Unprocessable Entity

  Same fields as `400`.

- **`429`** Too Many Requests

  Same fields as `400`.

- **`500`** Internal Server Error

  Same fields as `400`.

- **`502`** Bad Gateway

  Same fields as `400`.

## Example request

```bash tab="cURL"
curl -X POST 'https://api.solana.com/v1/wallets/signer-check' \
  -H "Authorization: Bearer $SDP_API_KEY" \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Content-Type: application/json" \
  -d '{
    "walletId": "privy_wallet_123"
  }'
```

```ts tab="TypeScript"
const res = await fetch("https://api.solana.com/v1/wallets/signer-check", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.SDP_API_KEY}`,
    "Idempotency-Key": crypto.randomUUID(),
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    "walletId": "privy_wallet_123"
  })
});
```

```python tab="Python"
import os, requests, uuid

r = requests.post("https://api.solana.com/v1/wallets/signer-check",
  headers={"Authorization": f"Bearer {os.environ['SDP_API_KEY']}", "Idempotency-Key": str(uuid.uuid4())},
  json={
    "walletId": "privy_wallet_123"
  })
```

## Example responses

```json tab="200"
{
  "data": {
    "walletId": "privy_wallet_123",
    "walletAddress": "So11111111111111111111111111111111111111112",
    "feePayer": "So11111111111111111111111111111111111111112",
    "memo": "SDP signer check 123e4567-e89b-42d3-a456-426614174000",
    "signature": "sig_example",
    "simulated": true,
    "checkedAt": "2026-02-20T00:00:00.000Z"
  },
  "meta": {
    "requestId": "req_example",
    "timestamp": "2025-01-01T00:00:00.000Z"
  }
}
```

```json tab="403"
{
  "error": {
    "code": "INSUFFICIENT_PERMISSIONS",
    "message": "Missing action: wallets.execute",
    "details": {
      "action": "wallets.execute"
    }
  },
  "meta": {
    "requestId": "req_example"
  }
}
```

Error responses use the [standard error shape](/docs/reference/conventions/errors).