Fireproof JSON ServerSAFE
Store and load JSON documents from LLM tool use
Overview
From the repository's own README, as read at the audited commit. Badges and raw HTML are left out.
This is a simple example of how to use a Fireproof database in a Model Context Protocol server (used for plugging code and data into A.I. systems such as Claude Desktop).
This demo server implements a basic JSON document store with CRUD operations (Create, Read, Update, Delete) and the ability to query documents sorted by any field.
Installation
Install dependencies:
npm install npm build
Running the Server
To use with Claude Desktop, add the server config:
On MacOS: ~/Library/Application Support/Claude/claude_desktop_config.json On Windows: %APPDATA%/Claude/claude_desktop_config.json
{
"mcpServers": {
"fireproof": {
"command": "/path/to/fireproof-mcp/build/index.js"
}
}
}Debugging
Since MCP servers communicate over stdio, debugging can be challenging. We recommend using the MCP Inspector, which is available as a package script:
npm run inspector
The Inspector will provide a URL to access debugging tools in your browser.
72ceea701048OBSERVED · 2026-10-08Connect
Built from this server's own package name, version and transport as found in its source — not copied from anyone's documentation, so it cannot drift against a page we do not control.
claude mcp add todos -- npx -y [email protected]
{
"mcpServers": {
"todos": {
"command": "npx",
"args": [
"-y",
"[email protected]"
]
}
}
}Exposed tools (4)
2 read · 1 write · 1 destructive. Blast radius: 1 tool can delete or overwrite — an agent that can be talked into calling a tool can be talked into calling this one.
| Tool | Risk | Description |
|---|---|---|
delete_json_doc | destructive | Delete a JSON document by ID |
load_json_doc | read | Load a JSON document by ID |
query_json_docs | read | Query JSON documents sorted by a field |
save_json_doc | write | Save a JSON document |
Trust audit
SAFEgrade B · trust 89/100 Nothing in the source contradicts what it says it does. Grade A is reserved for packages that have also passed the behavioural sandbox.
| Layer | What it checks | Result |
|---|---|---|
| L0 | Provenance & inventory | PASS |
| L1 | Static analysis of the code | PASS |
| L2 | Instruction surface (what it tells the agent) | PASS |
| L3 | Class-specific surface | WARN |
| L4 | Behavioural (sandbox) | SKIPPED |
What the source does
- Filesystem
- declared (1 observation(s))
- Network
- none-observed
- Shell
- none-observed
- Dependencies
- not all pinned
- Secrets in source
- none-found
Findings (2)
delete_json_doc
@fireproof/cloud, use-fireproof, @types/node, typescript
Gates applied: no_behavioural_pass.
72ceea701048full audit observations/trust-audit/mcp-server/fireproof-storage__fireproof-json-server.json · Report an issue / request a re-scanAudit history
Every audit this server has had. A grade with a past is a grade somebody is still checking.
| Date | Source | Verdict | Grade | Score | Change |
|---|---|---|---|---|---|
| 2026-10-08 | 72ceea701048 | SAFE | B | 89 | first audit |
Questions
What is the Fireproof JSON Server MCP server?
Store and load JSON documents from LLM tool use
What tools does Fireproof JSON Server expose?
4 in total: 2 read-only, 1 that write, and 1 that can delete or overwrite (delete_json_doc). Every one is listed on this page with its risk.
Is Fireproof JSON Server safe to connect to an agent?
The audit found nothing in the source that contradicts what it says it does, and graded it B (89/100). Grade A is held back for packages that have also passed a sandboxed behavioural run, which is why a clean server reads B. Separately from the audit: 1 of its tools can destroy data, so scope the token you give it to what you actually need.
What credentials does Fireproof JSON Server need?
No credential environment variables were found in its source, so it appears to need none.
How does Fireproof JSON Server run?
It speaks stdio, so it runs as a local process your client starts. It is published on npm as todos at 0.1.0.
How current is this page?
The grade is for one exact copy of the source (72ceea701048), read on 2026-10-08. The repository is watched and re-audited when it changes.