---
title: "Sign a token"
method: POST
path: "/v1/kms/issuers/{issuerId}/sign/token"
tags: ["kms"]
---

# Sign a token

`POST /v1/kms/issuers/{issuerId}/sign/token`

## Request

- Base URL: `https://api.vercel.com`
- URL: `https://api.vercel.com/v1/kms/issuers/{issuerId}/sign/token`
- Auth: HTTP bearer

Sign a JWT with a KMS issuer's active signing key. Authenticate the request with a Vercel OIDC token in the `Authorization: Bearer` header; the issuer's policies decide which workloads are allowed to sign. `keyId`, `algorithm`, and `fingerprint` identify the signing key in the issuer's JWKS.

## Path parameters

- `issuerId` string, required: The ID of the issuer.

## Request body

- object
  - `claims` object: The claims to include in the token.
  - `headers` object: Additional headers to include in the token.
  - `ttl` number, nullable: The time-to-live for the token, in seconds.

## Response `200`

- object
  - `algorithm` string, required: Algorithm of the signing key.
  - `fingerprint` string, required: SHA-256 fingerprint of the signing key's public key (`SHA256:<base64>`).
  - `keyId` string, required: Key id of the signing key. Matches the JWKS `kid` so verifiers can select the key after rotation without trial-verifying every published key.
  - `token` string, required: Compact JWT signed by the issuer's active signing key.

## Other responses

- `400`: One of the provided values in the request body is invalid. One of the provided values in the request query is invalid.
- `401`
- `403`
- `404`
- `429`

## Changes

- **2026-09-24** `dd6a90982ed0`: 3 info
  - added the required property `algorithm` to the response with the `200` status
  - added the required property `fingerprint` to the response with the `200` status
  - added the required property `keyId` to the response with the `200` status
- **2026-08-19** `6b6e0450635c`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/vercel/apis/vercel-api/changes/v1/kms/issuers/:issuerId/sign/token/post.md)

---

[API](https://skmtc.dev/vercel/apis/vercel-api.md) - [All operations](https://skmtc.dev/vercel/apis/vercel-api/llms.txt) - [OpenAPI document](https://skmtc.dev/vercel/apis/vercel-api/revisions/3311a68ee3e3?raw)