project-structure

Intro: This project is a monorepo managed by pnpm. It is a Language Server Protocol(LSP) implementation of Beancount (A plain text accounting Language).

Cursor rule for Cursor

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/fengkx/beancount-lsp/project-structure
Clone the repo
git clone --depth 1 https://github.com/fengkx/beancount-lsp

Made for: Cursor.

Per session 389 This file is loaded in full into every session.
When invoked 389 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00389 $0.00389
Opus 5 $0.00195 $0.00195
Sonnet 5 $0.00078 $0.00078
Haiku 4.5 $0.00039 $0.00039

Measured yesterday against content hash 359a1d517b0b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

project-structure 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 yesterday.

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.

.cursor/rules/project-structure.mdc · 23 lines

What it actually says

Intro: This project is a monorepo managed by pnpm. It is a Language Server Protocol(LSP) implementation of Beancount (A plain text accounting Language).

The project contains two part one lsp-server and lsp-client. server is a Language Server implemented LSP Spec. client is a VSCode Extension which connect to the server.

LSP Server: In the Language Server, we use web-tree-sitter and tree-sitter-beancount to parse the beancount files. And provide the ability to retrieve symbols from symbol index (defined in packages/lsp-server/src/common/features/symbol-index.ts). It can provide language server features like diagnostic and syntax highlight, code navigateion stuffs(go to definition / references). All tree-sitter queries are locationed in packages/lsp-server/src/common/language/queries. LSP features should follow the Feautre interface defined in packages/lsp-server/src/common/features/types.ts like all the existed one inside packages/lsp-server/src/common/features folder.

LSP Client: Clients communicate with server throgh LSP or JSON RPC with custom messages defined in packages/shared/src/messages.ts. Other than being a LanguageClient, it also provide LLM toolss. Tools interface should fullfiled ToolImpl defined in packages/lsp-client/src/common/llm/tools/tool.ts

Tips:

  • things like parsing, calculations work should be done in server side and communicate throght LSP
  • Reuse existed parsing and symbol index process when possible. Improve the existed one rather than create a new one
Changes

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.

  1. yesterday First seen · 23 lines · 389 tokens per session scan A 359a1d517b0b

Subscribe to this mod's changes

project-structure is a cursor rule published in the GitHub repository fengkx/beancount-lsp (48 stars, last pushed 3d ago), licensed MIT. It adds 389 tokens to every session, about $0.0019 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 2026-09-01.