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.
npx agentmods add rules/goranerhartic/cursor-development-rules/tdd-workflowgit clone --depth 1 https://github.com/GoranErhartic/cursor-development-rulesWhat 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 | $0.00021 | $0.00279 |
| Opus 5 | $0.00010 | $0.00139 |
| Sonnet 5 | $0.00004 | $0.00056 |
| Haiku 4.5 | $0.00002 | $0.00028 |
Grade A, and why
tdd-workflow 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.
What it actually says
TDD Workflow
Test-First Development is the default approach.
- RED - Write a failing test that defines expected behavior
- GREEN - Write minimal code to make the test pass
- REFACTOR - Clean up while keeping tests green
Escape Clause (Trivial Changes Only)
TDD may be skipped only when all of these are true:
- The change is non-behavioral (formatting, comments, renames, docs)
- Or the change is configuration-only (no runtime logic change)
- Or the change is a one-line mechanical fix with no branch/flow impact
- Existing tests already cover the touched behavior
When skipping TDD, document the exact reason in the summary.
Terminology
- Trivial change: A change that does not alter runtime behavior
- Non-trivial change: Any behavioral change, new branch, new condition, or side effect
See also: development/code-implementation.mdc, patterns/testing.mdc, development/tdd-planning.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.
- 2d ago First seen · 32 lines · 21 tokens per session scan A 96dad452cd6b
tdd-workflow is a cursor rule published in the GitHub repository GoranErhartic/cursor-development-rules (19 stars, last pushed 6mo ago), licensed MIT. It adds 21 tokens to every session and 279 once invoked, about $0.0001 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.
Other cursor rules, from other repositories
context-discipline
Manage AI context window efficiently - read before write, no re-reads, tool-call budgets, one-pass discipline.
token-efficiency
Token efficiency rules - eliminate waste in AI output, enforce read-before-write, prevent iteration cycles.
repository-layout
Canonical map of repo folders and docs.
conservative-file-creation
Check for existing files before creating. Be conservative about new files and code.
research-before-suggesting
Never make up features, APIs, or config options. Research before suggesting technical solutions.
122-swift-development
122: Swift development workflow including TDD, refactoring, and performance optimization.