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.

SERVERNostr Bray SOURCEnostr-bray

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/dev-forgesworn-bray/blossom-check.md

WHAT IT DOES

What blossom-check does on Nostr Bray

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.

RISK

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 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.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs blossom-check safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Nostr Bray, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For blossom-check, this is the rule to start with:

blossom-check Allowed

blossom-check is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

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

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Nostr Bray, apply this rule, and every blossom-check call is checked against it from then on.

FAQ

Questions about blossom-check

What does the blossom-check tool do? +

Verify a blob exists and is intact on a blossom server. HEAD request to check existence, optionally downloads and verifies SHA-256 hash matches. It is categorised as a Read tool in the Nostr Bray MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on blossom-check? +

Register the Nostr Bray MCP server in PolicyLayer and add a rule for blossom-check: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Nostr Bray. Nothing to install.

What risk level is blossom-check? +

blossom-check is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit blossom-check? +

Yes. Add a rate_limit block to the blossom-check rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block blossom-check completely? +

Set action: deny in the PolicyLayer policy for blossom-check. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides blossom-check? +

blossom-check is provided by the Nostr Bray MCP server (nostr-bray). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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