---
title: "Declare the writer signing key unavailable (owner + step-up)"
method: POST
path: "/vaults/v1/{vault_id}/writer-authority/declare-unavailable"
tags: ["vault"]
---

# Declare the writer signing key unavailable (owner + step-up)

`POST /vaults/v1/{vault_id}/writer-authority/declare-unavailable`

## Request

- Base URL: `https://api.run402.com`
- URL: `https://api.run402.com/vaults/v1/{vault_id}/writer-authority/declare-unavailable`
- Auth: one of:
  - API key in header `SIGN-IN-WITH-X`
  - HTTP bearer

Owner + step-up (`gitvault.rotate`, protocol rev 42 D202). An explicit, audited, wire-visible fact for when the writer signing key is known to be gone — the platform cannot itself observe this without the declaration. Feeds the seven-state full-history-on-join bridge vocabulary's `WRITER_AUTHORITY_UNAVAILABLE` terminal. Idempotent: re-declaring re-stamps the latest declarer and timestamp.

## Path parameters

- `vault_id` string, required

## Headers

- `SIGN-IN-WITH-X` string, required

## Response `200`

The declaration, as stored

- object
  - `declared_at` string, date-time
  - `declared_by` string, nullable: The declaring principal id, or null when declared by platform staff via an admin key.

## Other responses

- `403`: VAULT_ACCESS_DENIED

---

[API](https://skmtc.dev/run402/apis/run402-api.md) · [All operations](https://skmtc.dev/run402/apis/run402-api/llms.txt) · [OpenAPI document](https://skmtc.dev/run402/apis/run402-api/revisions/893607557f50?raw)