Skills/npm/fireflyiii-mcp

fireflyiii-mcp@1.0.0

VERIFIED· startup only

Publisher claims: "MCP server for Firefly III personal finance manager" Observed in sandbox: no network, touches nothing outside the project, writes no memory.

Registry npm (MCP server)Publisher daften · publishing for 175 daysInstalls 2,601Last detonated 3d ago
$claude mcp add fireflyiii-mcp -- npx -y @daften/fireflyiii-mcp
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Coverage

Startup only; authenticated tool behavior not tested.
Tested
server startup over stdio (initialize sent) · every file read, file written and host contacted by what ran
Not tested
the tool list (the server exited before answering) · what the tools do when called with real credentials
Needs
FIREFLY_TOKEN — give it to the server where it runs, through vet-skills run --secrets, so the value never enters the server's environment. Never paste a credential into a chat, a ticket or a report.

What this means for the label: Verified here covers what ran. The server's tools were not exercised with a real credential, so nothing about their behavior is asserted; the credential summary below says what to do with that.

Before you give it your token

It will ask for
FIREFLY_OAUTH_CLIENT_IDFIREFLY_TOKENConfiguration, not credentials: FIREFLY_DEBUG, FIREFLY_URL, MCP_ALLOWED_REDIRECT_PREFIXES, MCP_BASE_URL, MCP_GROUPS, MCP_PRESET, MCP_READ_ONLY
Where it talks to
no vendor host named in the codeAlso claude.ai, claude.com, attacker.test — not the publisher's domain; check what for before connecting.
What the honeypot saw
no credential files read · no network
What we could not test
the tool list (the server exited before answering) · what the tools do when called with real credentials

Connect it with a scoped credential, under the guard, and read the third-party hosts first. The code names claude.ai, claude.com, attacker.test as well as its own vendor. The guard injects FIREFLY_OAUTH_CLIENT_ID, FIREFLY_TOKEN only into requests to the host you bind (and its subdomains) and refuses the rest.

$vet-skills run --net declared -- npx -y @daften/fireflyiii-mcp

Never paste a credential into a chat, a ticket or a report, including ours. How the guard holds it.

Is [email protected] safe to install?

KillerSkills ran it in the KillerSkills honeypot sandbox (2 scenarios; startup only; authenticated tool behavior not tested) on 2026-11-11 and scored it 81/100 (Verified). In what ran, nothing we could detect went wrong: no undeclared network egress, no credential reads, no persistent instruction writes. What it does with a real credential was not observed (it asks for FIREFLY_TOKEN); the static findings and the publisher carry the rest of the score. Summary: no network, touches nothing outside the project, writes no memory.

Behavior trace

Honeypot run · 53 s · 2 scenarios · 0 deviations
t+CategoryObserved action
0.0sprocessno install scripts in bundle
13sprocessdependency install exit 0
33sprocessrelaunched with a decoy FIREFLY_TOKEN (tagged; nothing real)
53sclaimedstartup only: exited before answering, asking for FIREFLY_TOKEN (a decoy value was refused)
53sprocessscript backend runs setup only
53sprocessno install scripts to re-run

Static findings

LOW
URL to a private-network addressdist/http.js:103 · URL to a private-network address — a LAN or development target// comparing). The one exception is the port-wildcard form 'http://192.168.1.10:' (aFix: Replace encoded or assembled strings with plain literals and remove undeclared network calls.
AST07
HIGH
Access to sensitive file pathsdist/index.js:39 · Access to sensitive file paths — SSH keys, AWS credentials, env files, or system files'See .env.example for configuration instructions.\n');Fix: Stop enumerating or reading credential locations; take secrets from a declared environment variable the user sets on purpose.
AST05
MEDIUM
Process kill commanddist/http.d.ts:18 · Process kill command — agent can terminate processes* memory or, past V8's maximum string length, throw inside the stream listener and kill the process.Fix: Build commands from fixed arguments; do not interpolate untrusted strings into a shell.
AST05
HIGH
Access to sensitive file pathspackage.json:20 · Access to sensitive file paths — SSH keys, AWS credentials, env files, or system files"dev": "dotenv -e .env -- tsx src/index.ts",Fix: Stop enumerating or reading credential locations; take secrets from a declared environment variable the user sets on purpose.
AST05
MEDIUM
MCP server using network transport (SSE/HTTP)dist/http.d.ts:36 · MCP server using network transport (SSE/HTTP) — data sent over network…ng, port: number): Promise<void>; export declare function startHttpServer(createMcpServer: () => McpServer, host: string, requestedPort: number, portWasExplicit: boolean, oauthClientId: string | undefined, fireflyUrl: string, tryListenFn?:…Fix: Namespace tool names and keep tool descriptions literal; no instructions to the agent inside them.
AST04
MEDIUM
Process kill commanddist/http.js:25 · Process kill command — agent can terminate processes* memory or, past V8's maximum string length, throw inside the stream listener and kill the process.Fix: Build commands from fixed arguments; do not interpolate untrusted strings into a shell.
AST05
HIGH
Access to sensitive file pathspackage.json:14 · Access to sensitive file paths — SSH keys, AWS credentials, env files, or system files".env.example"Fix: Stop enumerating or reading credential locations; take secrets from a declared environment variable the user sets on purpose.
AST05
MEDIUM
MCP server using network transport (SSE/HTTP)dist/http.d.ts:33 · MCP server using network transport (SSE/HTTP) — data sent over networkexport declare function createMcpRequestHandler(createMcpServer: () => McpServer): (req: http.IncomingMessage, res: http.ServerResponse) => Promise<void>;Fix: Namespace tool names and keep tool descriptions literal; no instructions to the agent inside them.
AST04
HIGH
Access to sensitive file pathspackage.json:28 · Access to sensitive file paths — SSH keys, AWS credentials, env files, or system files"test:integration": "dotenv -e .env.test -- vitest run src/tests/integration.test.ts",Fix: Stop enumerating or reading credential locations; take secrets from a declared environment variable the user sets on purpose.
AST05
HIGH
Access to sensitive file pathsdist/index.js:24 · Access to sensitive file paths — SSH keys, AWS credentials, env files, or system files'See .env.example for configuration instructions.\n');Fix: Stop enumerating or reading credential locations; take secrets from a declared environment variable the user sets on purpose.
AST05
MEDIUM
File permission modification commandpackage.json:17 · File permission modification command — agent changes file ownership/permissions"build": "tsc && chmod +x dist/index.js",Fix: Request the narrowest permission that works; replace wildcards with the exact paths or hosts.
AST05

Cost to the agent

Instructions loaded
≈52 tok
1 file · 54 in bundle
Tool list per prompt
≈0 tok
0 tools · 0 per tool
Handshake
no reply
launch to tools/list, stdio
Undocumented tools
0
description under 20 chars · avg 0

Tokens estimated at four characters each. The tool list is re-read by the agent on every turn, so it is the number to compare between servers that do the same job: ranked across the index.

Known vulnerabilities

No advisories in OSV for @daften/fireflyiii-mcp@1.0.0 as of 3d ago. This is the package itself, not its dependencies.

fireflyiii-mcp@1.0.0 safety verdict: Verified (startup only) — KillerSkills