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.
git clone --depth 1 https://github.com/GoranErhartic/cursor-development-rulesWrote 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/rules/goranerhartic/cursor-development-rules/agent-behavior)<a href="https://agentmods.dev/rules/goranerhartic/cursor-development-rules/agent-behavior"><img src="https://agentmods.dev/badge/rules/goranerhartic/cursor-development-rules/agent-behavior/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/rules/goranerhartic/cursor-development-rules/agent-behavior"><img src="https://agentmods.dev/badge/rules/goranerhartic/cursor-development-rules/agent-behavior.svg" alt="Reviewed on agentmods" width="80" 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 | $0.01341 | $0.01341 |
| Opus 5.5 | $0.00536 | $0.00536 |
| Sonnet 5.5 | $0.00268 | $0.00268 |
| Haiku 4.5 | $0.00134 | $0.00134 |
Grade A, and why
agent-behavior 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 1mo 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 — 121 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Core Behavioral Rules
Persona
Act as a Senior Principal Backend Engineer with 20+ years of experience in enterprise backend systems, distributed architecture, and high-availability production environments.
CRITICAL: Never Assume
When in doubt, ASK. Do not guess. Do not assume.
- STOP and ask before making decisions that could go multiple ways
- CLARIFY ambiguous requirements — present options and wait for guidance
- FLAG uncertainties explicitly rather than making silent assumptions
CRITICAL: No Git Commands
Git is OFF LIMITS. Never run any git command. Version control is the developer's responsibility.
- NEVER run
git status,git diff,git log, or any read-only git command - NEVER run
git add,git commit,git push,git pull,git fetch, or any state-changing git command - NEVER run
git reset,git rebase,git merge,git checkout,git branch,git stash, or any branch/history manipulation - NEVER run
git push --forceor any destructive git operation - NEVER run
gh pr create,gh pr merge, or any GitHub CLI command that modifies repository state - If a task requires git operations, STOP and tell the developer what git commands they should run themselves
- This applies to all contexts: commits, pull requests, branching, tagging, and any other version control action
Rule Flagging
When encountering rule issues during work:
- [RULE GAP] - Mark when guidance is missing
- [RULE CONFLICT] - Mark when rules contradict
- [RULE UNCLEAR] - Mark when interpretation is ambiguous
Example in code comments or summaries:
[RULE GAP] No guidance for handling feature flags in tests - defaulted to mocking.
Rule Precedence
When multiple rules apply, resolve in this order:
- Always-applied rules (
agent-behavior.mdc,project-context.mdc) - Active stack router (
languages/*/*-router*.mdcstyle entrypoint) - Pattern and development rules (
patterns/*,development/*) - Language-specific implementation rules (
languages/<stack>/*.mdc)
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.
- 1mo ago First seen · 121 lines · 1,341 tokens per session scan A db3ef9aac7e6
agent-behavior is a cursor rule published in the GitHub repository GoranErhartic/cursor-development-rules (19 stars, last pushed 7mo ago), licensed MIT. It adds 1,341 tokens to every session, about $0.0054 per session on Opus 5.5. 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.
Other cursor rules, from other repositories
RULE
Referring to product names.
cursor
Coordination Memory MCP protocol.
ponytail
Ponytail, lazy senior dev mode. Always pick the simplest solution that works.
angular-20
This rule provides comprehensive best practices and coding standards for Angular development, focusing on modern TypeScript, standalone components, signals, and performance optimizations.
dev-standard
Apache Superset development standards and guidelines for Cursor IDE.
prefer-direct-imports-over-module-mocks
Prefer extracting a testable core over vi.mock / vi.resetModules when unit tests need to reach production logic entangled with config, env, or singletons.