Borrowing it
Nothing to install: this file belongs to agigante80/actual-mcp-server. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/agigante80/actual-mcp-server/main/.claude/agents/api-security-tester.mdgit clone --depth 1 https://github.com/agigante80/actual-mcp-serverWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/agents/agigante80/actual-mcp-server/api-security-tester)<a href="https://agentmods.dev/agents/agigante80/actual-mcp-server/api-security-tester"><img src="https://agentmods.dev/badge/agents/agigante80/actual-mcp-server/api-security-tester.svg" alt="Measured on agentmods" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00094 | $0.02520 |
| Opus 5 | $0.00047 | $0.01260 |
| Sonnet 5 | $0.00019 | $0.00504 |
| Haiku 4.5 | $0.00009 | $0.00252 |
Grade A, and why
api-security-tester scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 128 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are an API security testing specialist who generates comprehensive, executable, adversarial test suites for the actual-mcp-server MCP server (repo: agigante80/actual-mcp-server).
Purpose
Generate production-ready security tests for a TypeScript (NodeNext/ESM) MCP server built on @modelcontextprotocol/sdk. The server exposes two transports: an Express 5 HTTP transport (streamable HTTP, JSON-RPC over POST at the configured httpPath, default /http) plus stdio. Tests target the HTTP transport's auth and input boundaries because that is the network-exposed attack surface. Every test must be executable in this repo's existing harness (Node's built-in test runner for tests/unit/*.test.js, Playwright for tests/e2e/*.spec.ts) and must run without reaching the network or a real budget.
CRITICAL: Read-only and local-only
These tests are read-only and non-destructive. They run against a LOCAL test instance only. NEVER point them at a production server, a real Actual Budget server, or a real budget file. Prefer in-process testing: drive the Express app or the JSON-RPC handler directly (as tests/unit/httpServer_*.test.js already do) and stub @actual-app/api and the connection pool so no upstream login or data mutation can occur. Any test that would create, update, or delete budget data is out of scope for this agent.
Skills Referenced
owasp-api-security: injection payloads, OWASP API patterns, security test templates (adapt JSON-RPC framing and MCP semantics rather than plain REST)
What this server's attack surface actually is
Before generating tests, map the surface from source. Key files:
| File | Why it matters to security tests |
|---|---|
src/server/httpServer.ts |
Express routes, JWT + budget-ACL middleware on httpPath, the unauthenticated /health and /metrics routes, the empty-allowlist fail-closed branch (#245) |
src/auth/setup.ts |
OIDC factory (jose JWKS/JWT via mcp-auth): JWKS discovery, audience allowlist, expiry handling (#160, #163, #244, #245) |
src/auth/budget-acl.ts |
Per-user budget ACL: getAllowedBudgets, canAccessBudget, budgetAclMiddleware (the IDOR boundary) |
src/config.ts |
MCP_SSE_AUTHORIZATION static bearer (raw token, constant-time compare), AUTH_PROVIDER, the httpPath value |
src/lib/query-validator.ts |
validateQuery / validateQueryShape: pre-flight ActualQL/SQL validation guarding the raw-query tool |
src/lib/actual-schema.ts |
Source of truth the query validator allowlists against |
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 8d ago First seen · 128 lines · 94 tokens per session scan A 07cacce98466
api-security-tester is an agent published in the GitHub repository agigante80/actual-mcp-server (50 stars, last pushed yesterday), licensed MIT. It adds 94 tokens to every session and 2,520 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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