Grades are a hygiene check, not a security guarantee.

MCP, MCP server

Bruno MCP Studio

Turns an agent's API testing into files you keep: it authors and edits Bruno collections in place, then runs them — HTTP, WebSocket and gRPC, one identity or many — and reports per-request pass/fail you can re-run in CI.

Compatibility: Not stated.

Grade D

Two or more Medium findings, or a High finding. Only try it in a sandbox.

Graded by PlugVetRubric v2

Not a guarantee. A hygiene check of the source at the commit shown, not a security audit.

Rescanned at commit d1cef941fe38, unchanged since the check below.

INSTALL_LIFECYCLE_HOOK SECRETS_PATH_CREDENTIAL

Why this grade

  • INSTALL_LIFECYCLE_HOOK Medium

    A package install hook (preinstall, install, postinstall or prepare) runs a script.

    package.json, line 36 prepare

  • SECRETS_PATH_CREDENTIAL Medium

    Mentions a credential store path (~/.ssh, id_rsa, .npmrc, .aws/credentials, credentials.json, .netrc).

    src/bruno/upload-path.ts, line 45 * collection could name `/etc/passwd`, `~/.ssh/id_rsa`, an env file, etc. and

Any High, or two or more Medium findings, give D. One Medium gives C. Low findings or a security Note give B. Each code names a finding behind the letter.

Grades are a hygiene check of the source at the commit shown, on the date checked, not a security audit or a guarantee. The free directory grades are automated. Before release, a PlugVet engineer reviews every paid report and any grade we hold back, including all F grades, against the source code and the evidence we quote.

What was checked

Plain notes from the hygiene checks.

  • Permissions

    Concern

    can delete files.

    PERMISSION_DELETE_FILES

    src/bruno/environment.ts, line 590

    await fs.unlink(envFilePath);

    src/bruno/request-move.ts, line 126

    await fs.unlink(filePath);

    src/tools/collection-lifecycle-tools.ts, line 206

    await fs.rm(args.collectionPath, { recursive: true, force: true });

    Show more

    tools/comprehension/preflight.mjs, line 85

    await fs.rm(gutted, { force: true });

    tools/comprehension/preflight.mjs, line 150

    await fs.rm(root, { recursive: true, force: true });

    tools/comprehension/run.mjs, line 298

    if (!keep) await fs.rm(root, { recursive: true, force: true });

    tools/comprehension/run.mjs, line 301

    if (guttedPath && !keep) await fs.rm(guttedPath, { force: true });

  • Install and update

    Concern

    runs a script at install time. The docs document an installer that pipes a download into a shell.

    INSTALL_LIFECYCLE_HOOK INSTALL_DOCUMENTED_INSTALLER

    package.json, line 36

    prepare

    docs/mcp.md, line 6823

    curl -LsSf https://astral.sh/uv/install.sh | sh

  • Network

    Concern

    can reach a host that is not written as a fixed address. can reach api.weather.com. The description does not name that host.

    NETWORK_NO_FIXED_HOST NETWORK_UNNAMED_HOST

    src/bruno/fetch-dispatcher.ts, line 81

    * settings and nothing to pin - so the caller falls back to global fetch().

    src/bruno/request-executor.ts, line 696

    // TLS/proxy settings: without one the request would go through global fetch(),

    src/bruno/request-redaction.ts, line 93

    *. Real fetch() strips these on a cross-origin redirect; the

    Show more

    src/bruno/url-validator.ts, line 29

    * fetch() re-resolves independently and an attacker-controlled short-TTL record

    src/bruno/ws-transport.ts, line 562

    socket = new WebSocket(dialUrl, terms.protocols, {

    docs/MCP Typescript readme.md, line 219

    const response = await fetch(`https://api.weather.com/${city}`);

    docs/mcp.md, line 3863

    fetch("/mcp", {

    docs/mcp.md, line 4231

    const response = await fetch(serverUrl, {

  • Secrets

    Concern

    reads a credential or environment file.

    SECRETS_PATH_CREDENTIAL SECRETS_PATH_DOTENV

    src/bruno/collection.ts, line 69

    ignore: input.ignore || ['node_modules', '.git', '.env']

    src/bruno/collection.ts, line 343

    .env

    src/bruno/upload-path.ts, line 45

    * collection could name `/etc/passwd`, `~/.ssh/id_rsa`, an env file, etc. and

    Show more

    src/bruno/collection.ts, line 344

    .env.local

    src/bruno/collection.ts, line 345

    .env.*.local

    src/bruno/upload-path.ts, line 53

    * dotfiles and dot-directories (`~/.ssh`, `.aws`, `.env`, `.git`, …) are not

    .gitignore, line 26

    # Environment files

    .gitignore, line 27

    .env

  • Agent instructions

    Pass

    No instruction to ignore earlier instructions or to hide a step.

  • Obfuscation

    Note

    a file was over the read cap and was not fully read.

    OBFUSCATION_FILE_OVER_READ_CAP

    package-lock.json, line 1

    {

    docs/mcp.md, line 1

    # Example Clients

  • Licence

    Pass

    A licence file is present (LICENSE).

  • Maintainer activity

    Pass

    The latest commit is within the last 365 days.

Get the full report on this tool, £49

Note

Hygiene check of commit d1cef941fe38. can delete files. runs a script at install time. The docs document an installer that pipes a download into a shell. can reach a host that is not written as a fixed address. can reach api.weather.com. The description does not name that host. reads a credential or environment file. a file was over the read cap and was not fully read.

Date and source

Date checked:

View source

github.com

Commit graded: d1cef941fe384e6e6a45ff59fc6389cce05d8c76

This link goes to the original host. PlugVet does not host or check what you download from there, and installing it is your own decision and risk.

Read how this letter is chosen