blossom-upload

Upload a file to a blossom media server. Returns the blob URL and SHA-256 hash.

SERVERNostr Bray SOURCEnostr-bray

Medium RISK CLASS

Category Write

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

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

WHAT IT DOES

What blossom-upload does on Nostr Bray

AI agents use blossom-upload to create or update resources in Nostr Bray, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Nostr Bray environment.

RISK

Why blossom-upload is rated Medium

This tool uploads and stores files, which is a reversible write operation. While it creates data permanently, files can typically be deleted later (evidenced by the sibling tool 'blossom-delete').

From the tool's definition Tool performs 'Upload a file to a blossom media server', which creates new data on the server. It returns a blob URL and SHA-256 hash, confirming persistent storage.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs blossom-upload 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-upload, this is the rule to start with:

blossom-upload Rate-limited

blossom-upload stays usable, but capped: an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "blossom-upload": {
      "limits": [
        {
          "counter": "blossom-upload_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT 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-upload call is checked against it from then on.

FAQ

Questions about blossom-upload

What does the blossom-upload tool do? +

Upload a file to a blossom media server. Returns the blob URL and SHA-256 hash. It is categorised as a Write tool in the Nostr Bray MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

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

Register the Nostr Bray MCP server in PolicyLayer and add a rule for blossom-upload: 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-upload? +

blossom-upload is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit blossom-upload? +

Yes. Add a rate_limit block to the blossom-upload 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-upload completely? +

Set action: deny in the PolicyLayer policy for blossom-upload. 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-upload? +

blossom-upload 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.

KEEP EXPLORING

More on Nostr Bray, and thousands of servers like it.

This server

All 240 Nostr Bray tools →

Across the catalogue

The MCP Attack Database →

Guides

Govern customer-ops agents →Argument validation →Scoped token →