---
title: "Get a specific public signing key."
method: GET
path: "/api/signing-key/{keyId}"
tags: ["Signing"]
---

# Get a specific public signing key.

`GET /api/signing-key/{keyId}`

Returns a retained public signing key by its id, in PEM form. A key that has been superseded by a regeneration is kept, because redaction-ledger entries signed with it must remain verifiable. Ledger entries and exports name the key that signed them in their signingKeyId field. This endpoint does not require authentication.

## Path parameters

- `keyId` string, required

## Response `200`

The public key with the given id.

- string

## Other responses

- `400` — Bad Request
- `401` — Unauthorized
- `404` — No key with that id is retained.
- `413` — Content Too Large
- `415` — Unsupported Media Type
- `500` — Internal Server Error
- `503` — Service Unavailable

---

[API](https://skmtc.net/philterd/apis/philter-api.md) · [All operations](https://skmtc.net/philterd/apis/philter-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/philterd/philter-api/versions/67443cd5a65b/schema)