api-boundary

Rules for the HTTP boundary between the Rust Axum server and the web client, including routes, request limits, and data formats.

In plain words
What is it for?
Use it when changing solver routes, HTTP contracts, scan sessions, validation, or the matching web client.
Why use it?
It prevents the server, puzzle engine, and browser client from disagreeing about requests, responses, errors, or validation.

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/williamisnotdefined/rubiks-cube-solver/api-boundary
Clone the repo
git clone --depth 1 https://github.com/williamisnotdefined/rubiks-cube-solver

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 3,050 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 $0.03050
Opus 5 $0.00000 $0.01525
Sonnet 5 $0.00000 $0.00610
Haiku 4.5 $0.00000 $0.00305

Measured 2d ago against content hash 9dc33260384b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

api-boundary 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/api-boundary.mdc · 207 lines

How it starts

The opening of the file, as written. The whole thing — 207 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Generated from ai/registry.json. Do not edit manually.

Canonical skill: ../../ai/skills/api-boundary.md.

Referenced context:

  • ../../ai/rules/api-rules.md
  • ../../ai/rules/frontend-rules.md
  • ../../ai/rules/testing-rules.md
  • ../../ai/architecture/api-boundary.md

This file is compiled from canonical AI knowledge files. Edit canonical files under ai, then run npm run ai:sync.

Compiled AI Skill: api-boundary

Canonical Skill: ai/skills/api-boundary.md

API Boundary

Use for Axum routes, contracts, validation, solver loading, scan sessions, or the matching web API client.

Read First

  • ai/rules/api-rules.md
  • ai/rules/frontend-rules.md
  • ai/rules/testing-rules.md
  • ai/architecture/api-boundary.md

Workflow

  • Inspect the focused route/response/solve modules and matching client contract.
  • Keep engine semantics in Rust, HTTP limits and status mapping in Axum, and normalization in the web API domain.
  • Preserve typed scan stickers and the server-side 308 WCA docs redirect where affected.
  • Run API tests plus web tests/build when the browser contract changes.

Referenced Context

Reference: ai/rules/api-rules.md

API Rules

Rules for the Axum HTTP API and the frontend API contract.

Always

  • Keep route handlers thin: extract state and JSON, validate request limits, choose the solver strategy, delegate to Rust engine code, and map results to HTTP responses.
  • Keep solver behavior in cube-engine; crates/api owns HTTP shape, safety limits, generated-solver loading, CORS, and error/status mapping.
  • Use Serde request and response structs as the API contract.
  • Keep notation solve requests on move notation and route scan solves through typed scan-session contracts, which MAY include reviewed stickers and manual overrides.
  • Validate API safety limits before parsing notation or invoking search.
  • Use named constants for public API caps such as maximum depth, maximum nodes, notation bytes, and JSON body bytes.
  • Preserve stable response status strings, error kinds, and metadata fields because apps/web/src/api normalizes them.
  • Verify returned solutions by replay before reporting success.
  • Keep generated pruning-table availability and corruption errors explicit in API responses.
  • Keep CORS origins narrow to known local web development and preview origins unless deployment requirements change.
  • Update apps/web/src/api types and normalization when API response fields or status values change.
  • Keep /api/wca-data as an Axum HTTP 308 redirect to /api/wca-data/v1/docs; WCA data endpoints belong to apps/wca-data.

Read the full file on GitHub · 207 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 · 207 lines · 0 tokens per session scan A 9dc33260384b

Subscribe to this mod's changes

api-boundary is a cursor rule published in the GitHub repository williamisnotdefined/rubiks-cube-solver (4 stars, last pushed 8d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 3,050 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 2026-08-31.