---
title: "POST /#X-Amz-Target=TrentService.PutKeyPolicy"
method: POST
path: "/#X-Amz-Target=TrentService.PutKeyPolicy"
---

# POST /#X-Amz-Target=TrentService.PutKeyPolicy

`POST /#X-Amz-Target=TrentService.PutKeyPolicy`

Attaches a key policy to the specified KMS key.

For more information about key policies, see [Key Policies](https://docs.aws.amazon.com/kms/latest/developerguide/key-policies.html) in the _Key Management Service Developer Guide_. For help writing and formatting a JSON policy document, see the [IAM JSON Policy Reference](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies.html) in the __Identity and Access Management User Guide__ . For examples of adding a key policy in multiple programming languages, see [Setting a key policy](https://docs.aws.amazon.com/kms/latest/developerguide/programming-key-policies.html#put-policy) in the _Key Management Service Developer Guide_.

**Cross-account use**: No. You cannot perform this operation on a KMS key in a different Amazon Web Services account.

**Required permissions**: [kms:PutKeyPolicy](https://docs.aws.amazon.com/kms/latest/developerguide/kms-api-permissions-reference.html) (key policy)

**Related operations**: GetKeyPolicy

## Headers

- `X-Amz-Target` 'TrentService.PutKeyPolicy', required

## Request body

- PutKeyPolicyRequest
  - `KeyId` string, required — <p>Sets the key policy on the specified KMS key.</p> <p>Specify the key ID or key ARN of the KMS key.</p> <p>For example:</p> <ul> <li> <p>Key ID: <code>1234abcd-12ab-34cd-56ef-1234567890ab</code> </p> </li> <li> <p>Key ARN: <code>arn:aws:kms:us-east-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab</code> </p> </li> </ul> <p>To get the key ID and key ARN for a KMS key, use <a>ListKeys</a> or <a>DescribeKey</a>.</p>
  - `PolicyName` string, required — The name of the key policy. The only valid value is <code>default</code>.
  - `Policy` string, required — <p>The key policy to attach to the KMS key.</p> <p>The key policy must meet the following criteria:</p> <ul> <li> <p>The key policy must allow the calling principal to make a subsequent <code>PutKeyPolicy</code> request on the KMS key. This reduces the risk that the KMS key becomes unmanageable. For more information, see <a href="https://docs.aws.amazon.com/kms/latest/developerguide/key-policy-default.html#prevent-unmanageable-key">Default key policy</a> in the <i>Key Management Service Developer Guide</i>. (To omit this condition, set <code>BypassPolicyLockoutSafetyCheck</code> to true.)</p> </li> <li> <p>Each statement in the key policy must contain one or more principals. The principals in the key policy must exist and be visible to KMS. When you create a new Amazon Web Services principal, you might need to enforce a delay before including the new principal in a key policy because the new principal might not be immediately visible to KMS. For more information, see <a href="https://docs.aws.amazon.com/IAM/latest/UserGuide/troubleshoot_general.html#troubleshoot_general_eventual-consistency">Changes that I make are not always immediately visible</a> in the <i>Amazon Web Services Identity and Access Management User Guide</i>.</p> </li> </ul> <p>A key policy document can include only the following characters:</p> <ul> <li> <p>Printable ASCII characters from the space character (<code>\u0020</code>) through the end of the ASCII character range.</p> </li> <li> <p>Printable characters in the Basic Latin and Latin-1 Supplement character set (through <code>\u00FF</code>).</p> </li> <li> <p>The tab (<code>\u0009</code>), line feed (<code>\u000A</code>), and carriage return (<code>\u000D</code>) special characters</p> </li> </ul> <p>For information about key policies, see <a href="https://docs.aws.amazon.com/kms/latest/developerguide/key-policies.html">Key policies in KMS</a> in the <i>Key Management Service Developer Guide</i>.For help writing and formatting a JSON policy document, see the <a href="https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies.html">IAM JSON Policy Reference</a> in the <i> <i>Identity and Access Management User Guide</i> </i>.</p>
  - `BypassPolicyLockoutSafetyCheck` boolean — <p>Skips ("bypasses") the key policy lockout safety check. The default value is false.</p> <important> <p>Setting this value to true increases the risk that the KMS key becomes unmanageable. Do not set this value to true indiscriminately.</p> <p>For more information, see <a href="https://docs.aws.amazon.com/kms/latest/developerguide/key-policy-default.html#prevent-unmanageable-key">Default key policy</a> in the <i>Key Management Service Developer Guide</i>.</p> </important> <p>Use this parameter only when you intend to prevent the principal that is making the request from making a subsequent <a>PutKeyPolicy</a> request on the KMS key.</p>

## Response `200`

Success

## Other responses

- `480` — NotFoundException
- `481` — InvalidArnException
- `482` — MalformedPolicyDocumentException
- `483` — DependencyTimeoutException
- `484` — UnsupportedOperationException
- `485` — KMSInternalException
- `486` — LimitExceededException
- `487` — KMSInvalidStateException

---

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