agent-development

Project rules for building pydantic-ai agents, their tools, handlers, models, and prompt templates.

In plain words
What is it for?
Use them when adding or changing coordinator agents, tools, retry settings, model options, or YAML-based prompts.
Why use it?
They keep new agent code consistent with the project's structure, configuration, and supported model connections.

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/divar-ir/ai-doc-gen/agent-development
Clone the repo
git clone --depth 1 https://github.com/divar-ir/ai-doc-gen

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 702 The whole file, excluding the scripts and references it only reads on demand.
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 $0.00000 $0.00702
Opus 5 $0.00000 $0.00351
Sonnet 5 $0.00000 $0.00140
Haiku 4.5 $0.00000 $0.00070

Measured 2d ago against content hash af502e038615, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

agent-development 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 2d 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.

.cursor/rules/agent-development.mdc · 64 lines

How it starts

The opening of the file, as written. The whole thing — 64 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Agent Development

Agent construction

Agents are built as properties on coordinator classes (AnalyzerAgent, DocumenterAgent, AIRulesGeneratorAgent):

@property
def _structure_analyzer_agent(self) -> Agent:
    model, model_settings = self._llm_model
    return Agent(
        name="Structure Analyzer",
        model=model,
        model_settings=model_settings,
        system_prompt=self._render_prompt("agents.structure_analyzer.system_prompt"),
        tools=[FileReadTool().get_tool(), ListFilesTool().get_tool()],
        retries=config.ANALYZER_AGENT_RETRIES,
    )
  • Model setup is OpenAI-compatible only: OpenAIChatModel(model_name, provider=OpenAIProvider(base_url=..., api_key=..., http_client=create_retrying_client())). There is no Gemini/custom provider path.
  • ModelSettings: temperature 0.0, max_tokens, timeout, parallel_tool_calls — all from src/config.py env constants.

Prompts

  • Jinja2 templates in YAML under src/agents/prompts/ (keys like agents.<name>.system_prompt / user_prompt), loaded by PromptManager and rendered via self._render_prompt(key) with repo_path etc. as variables.
  • New agent → new prompt section in the matching YAML file, never inline prompt strings in Python.

Orchestration

  • Analyzer: build a dict of task callables (one per non-excluded analysis), run through WorkerPool(max_workers=self._config.max_workers).
  • AI-rules generator: fixed pair of tasks via asyncio.gather(*tasks, return_exceptions=True).
  • After the run, validate_succession(files): raise ValueError only if NO output file exists; warn on partial success listing missing files.
  • Each agent writes its own output file (.ai/docs/*.md, README.md, CLAUDE.md/AGENTS.md, .cursor/rules/*.mdc); create parent dirs and clean absolute paths first.

Tools

class FileReadTool:
    def get_tool(self):
        return Tool(self._run, name="Read-File", takes_ctx=False, max_retries=...)

    def _run(self, file_path: str, line_number: int = 0, line_count: int = 200) -> str:
        """Docstring is the LLM-facing description — keep Args/Returns accurate."""
        ...
        raise ModelRetry(message="File not found")  # recoverable errors → ModelRetry

Read the full file on GitHub · 64 lines

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. 2d ago First seen · 64 lines · 0 tokens per session scan A af502e038615

Subscribe to this mod's changes

agent-development is a cursor rule published in the GitHub repository divar-ir/ai-doc-gen (753 stars, last pushed 1mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 702 tokens. 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.