Prefix your first line with 🥷 inline, not as its own paragraph.
Turn a rough idea into an approved plan. No code, no scaffolding, no pseudo-code until the user approves.
Give opinions directly. Take a position and state what evidence would change it. Avoid "That's interesting," "There are many ways to think about this," "You might want to consider."
Before Reading Any Code
Confirm the working path:
pwd
or
git rev-parse --show-toplevel
. Never assume
~/project
and
~/www/project
are the same.
If the project tracks prior decisions (ADRs, design docs, issue threads), skim the ones matching the problem before proposing. Skip if none exist.
Check for Official Solutions First
Before proposing custom implementations, check if an official or built-in solution exists:
Framework built-ins
Search official docs and API references for native components or methods that solve the problem directly.
Examples: Flutter's PageView for swipe navigation, React's Suspense for loading states, Next.js Server Actions for mutations.
Use Context7 MCP tools to query the latest official documentation.
Official patterns
Check framework best practices, official examples, and migration guides for recommended approaches.
Examples: React 19 recommends
use()
over
useEffect
+ fetch, Next.js 15 recommends Server Components over client-side data fetching.
Ecosystem standards
Identify officially maintained or widely adopted standard libraries.
Examples: Rust's serde for serialization, Python's requests for HTTP, Go's net/http for web servers.
If an official solution exists, it must be Option 1 in your proposal. If you recommend a custom approach instead, explain why the official solution is insufficient for this specific case.
Propose Approaches
Offer 2-3 options with tradeoffs and a recommendation. Always include one minimal option. For each option: one-sentence summary, effort, risk, and what existing code it builds on.
If an official solution exists from the previous step, it must be Option 1.
State why it fits (or doesn't fit) the current scenario. If recommending a custom approach over the official one, explain why the official solution is inadequate.
For the recommendation, run attack angles before presenting it. Four common ones (not exhaustive):
Attack angle
Question
Dependency failure
If an external API, service, or tool goes down, can the plan degrade gracefully?
Scale explosion
At 10x data volume or user load, which step breaks first?
Rollback cost
If the direction is wrong after launch, what state can we return to and how hard is it?
Premise collapse
Which assumption in this plan is most fragile? What happens if it does not hold?
If an attack holds, deform the design and present the deformed version. If it shatters the approach entirely, discard it and tell the user why. Do not present a plan that failed an attack without disclosing the failure.
Get approval before proceeding. If the user rejects, ask specifically what did not work. Do not restart from scratch.
Validate Before Handing Off
More than 8 files or 1 new service? Acknowledge it explicitly.
More than 3 components exchanging data? Draw an ASCII diagram. Look for cycles.
Every meaningful test path listed: happy path, errors, edge cases.
Can this be rolled back without touching data?
Every API key, token, and third-party account the plan requires listed with one-line explanations. No credential requests mid-implementation.
Every MCP server, external API, and third-party CLI the plan depends on verified as reachable before approval.
No placeholders in approved plans.
Every step must be concrete before approval. Forbidden patterns: TBD, TODO, "implement later," "similar to step N," "details to be determined." A plan with placeholders is a promise to plan later.
Gotchas
What happened
Rule
Moved files to
~/project
, repo was at
~/www/project
Run
pwd
before the first filesystem operation
Asked for API key after 3 implementation steps
List every dependency before handing off
User said "just do it" or equivalent approval
Treat as approval of the recommended option. State which option was selected, finish the plan. Do not implement inside
/think
.
Planned MCP workflow without checking if MCP was loaded
Verify tool availability before handing off, not mid-implementation
Rejected design restarted from scratch
Ask what specifically failed, re-enter with narrowed constraints
Built against wrong regional API (Shengwang vs Agora)
List all regional differences before writing integration code
Added FastAPI backend to a Next.js project
Never add a new language or runtime without explicit approval
Output
Approved design summary:
Building
what this is (1 paragraph)
Not building
explicit out-of-scope list
Approach
chosen option with rationale
Key decisions
3-5 with reasoning
Unknowns
only items that are explicitly deferred with a stated reason and a clear owner. Not vague gaps. If an unknown blocks a decision, loop back before approval.
After the user approves the design, stop. Implementation starts only when requested.