# blossom-check

Verify a blob exists and is intact on a blossom server. HEAD request to check existence, optionally downloads and verifies SHA-256 hash matches.

Agent View of the PolicyLayer registry record for `blossom-check`. HTML page: https://policylayer.com/tools/dev-forgesworn-bray/blossom-check

## Facts

- Tool: `blossom-check`
- Server: Nostr Bray (`nostr-bray`) — https://policylayer.com/tools/dev-forgesworn-bray.md
- Install: `npx -y nostr-bray`
- Homepage: https://github.com/forgesworn/bray
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Allowed

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "blossom-check",
    "arguments": {}
  }
}
```

## Why blossom-check is rated Low

This tool retrieves metadata and optionally validates data integrity through cryptographic verification. It has no side effects on the blob itself or other system state. The hash verification is a passive check, not an execution or modification. Classification as Read is appropriate for integrity verification operations that query system state without altering it.

From the tool's own definition: "Tool performs verification via HEAD request and optional download with hash checking. Actions are read-only: 'Verify a blob exists', 'check existence', 'downloads and verifies' — no modification, deletion, or execution of the blob content."

## Use case

AI agents call blossom-check to retrieve information from Nostr Bray without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Nostr Bray:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "blossom-check": {}
  }
}
```

## Other tools on Nostr Bray (239)

- `blossom-delete` — Destructive — https://policylayer.com/tools/dev-forgesworn-bray/blossom-delete.md
- `group-remove-user` — Destructive — https://policylayer.com/tools/dev-forgesworn-bray/group-remove-user.md
- `label-remove` — Destructive — https://policylayer.com/tools/dev-forgesworn-bray/label-remove.md
- `marketplace-credentials-clear` — Destructive — https://policylayer.com/tools/dev-forgesworn-bray/marketplace-credentials-clear.md
- `marketplace-retire` — Destructive — https://policylayer.com/tools/dev-forgesworn-bray/marketplace-retire.md
- `social-delete` — Destructive — https://policylayer.com/tools/dev-forgesworn-bray/social-delete.md
- `tombstone` — Destructive — https://policylayer.com/tools/dev-forgesworn-bray/tombstone.md
- `trust-revoke` — Destructive — https://policylayer.com/tools/dev-forgesworn-bray/trust-revoke.md
- `vault-revoke` — Destructive — https://policylayer.com/tools/dev-forgesworn-bray/vault-revoke.md
- `zap-wallet-clear` — Destructive — https://policylayer.com/tools/dev-forgesworn-bray/zap-wallet-clear.md
- `cast-spell` — Execute — https://policylayer.com/tools/dev-forgesworn-bray/cast-spell.md
- `execute-action` — Execute — https://policylayer.com/tools/dev-forgesworn-bray/execute-action.md
- `identity-restore-shamir` — Execute — https://policylayer.com/tools/dev-forgesworn-bray/identity-restore-shamir.md
- `identity-switch` — Execute — https://policylayer.com/tools/dev-forgesworn-bray/identity-switch.md
- `marketplace-probe` — Execute — https://policylayer.com/tools/dev-forgesworn-bray/marketplace-probe.md
- `nip44-encrypt` — Execute — https://policylayer.com/tools/dev-forgesworn-bray/nip44-encrypt.md
- `onboard-verified` — Execute — https://policylayer.com/tools/dev-forgesworn-bray/onboard-verified.md
- `relay-auth` — Execute — https://policylayer.com/tools/dev-forgesworn-bray/relay-auth.md
- `trust-attest-chain` — Execute — https://policylayer.com/tools/dev-forgesworn-bray/trust-attest-chain.md
- `trust-ring-lsag-sign` — Execute — https://policylayer.com/tools/dev-forgesworn-bray/trust-ring-lsag-sign.md
- `trust-ring-prove` — Execute — https://policylayer.com/tools/dev-forgesworn-bray/trust-ring-prove.md
- `trust-spoken-verify` — Execute — https://policylayer.com/tools/dev-forgesworn-bray/trust-spoken-verify.md
- `vault-encrypt` — Execute — https://policylayer.com/tools/dev-forgesworn-bray/vault-encrypt.md
- `marketplace-pay` — Financial — https://policylayer.com/tools/dev-forgesworn-bray/marketplace-pay.md
- `zap-make-invoice` — Financial — https://policylayer.com/tools/dev-forgesworn-bray/zap-make-invoice.md
- `zap-send` — Financial — https://policylayer.com/tools/dev-forgesworn-bray/zap-send.md
- `article-list` — Read — https://policylayer.com/tools/dev-forgesworn-bray/article-list.md
- `article-read` — Read — https://policylayer.com/tools/dev-forgesworn-bray/article-read.md
- `badge-list` — Read — https://policylayer.com/tools/dev-forgesworn-bray/badge-list.md
- `blossom-discover` — Read — https://policylayer.com/tools/dev-forgesworn-bray/blossom-discover.md
- …and 209 more: https://policylayer.com/tools/dev-forgesworn-bray.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=dev-forgesworn-bray · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/dev-forgesworn-bray