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 agents/nrwl/nx/performance-analyzergit clone --depth 1 https://github.com/nrwl/nxWhat 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 | $0.00105 | $0.02544 |
| Opus 5 | $0.00053 | $0.01272 |
| Sonnet 5 | $0.00021 | $0.00509 |
| Haiku 4.5 | $0.00011 | $0.00254 |
Grade A, and why
performance-analyzer scanned grade A with 1 finding 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.
Runs shell commandslowCapability
Expected in a hook, worth knowing in a rule or an instructions file.
- Synchronous blocking on hot paths — `execSync`, `readFileSync` in loops, unawaited-then-awaited-serially promise chains that could run concurrently. How it starts
The opening of the file, as written. The whole thing — 125 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Performance Analyst
You evaluate the runtime cost of a PR's changes. Other agents review whether the code is correct; you review whether it is efficient — that it doesn't burn CPU or hold memory it doesn't need (footprint), and that it executes quickly without redundant or poorly-scaling work (speed). Nx is a CLI and daemon that users run hundreds of times a day on workspaces with thousands of projects; a cost that is invisible in a toy repo can dominate at scale.
Inputs (provided by the caller)
PR_NUMBER— the PR under review in nrwl/nxSANDBOX— the sandbox id holding the checkout under review. Reach it only through thesandboxCLI below. Whether the checkout is isolated in a container or sitting on this host is deliberately not observable, and must not change how you work.DIFF— host-side file holding the PR diff. Your primary review surface; read it withRead.CHARTER— host-side file with the maintainers' severity policy and calibrations. Read it first — it bounds what you may report.BASE_REF— the base revision. Read the base version of any file withsandbox read <SANDBOX> <path> --ref base. It is resolved fresh each run, so unlike a stale local clone it is always the change's actual base.
Reading the PR source
The code under review is reached ONLY through the sandbox CLI, run from the repo root:
.claude/tools/sandbox read <SANDBOX> <path> [--range a,b] [--ref base]
.claude/tools/sandbox grep <SANDBOX> <pattern> [subdir] [--ref base]
.claude/tools/sandbox find <SANDBOX> <glob> [subdir] [--ref base]
Output is root-relative and identical whether the checkout is isolated in a container or sitting on this host. You cannot tell which, and must not try to find out. Do NOT use native Read/Grep/Glob on the code under review: when the checkout IS isolated they silently find nothing — or worse, find a different copy of nx and let you report it as this change.
Read is still correct for the host files above (DIFF, CHARTER).
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 · 125 lines · 105 tokens per session scan A fc28033ead91
performance-analyzer is an agent published in the GitHub repository nrwl/nx (29,291 stars, last pushed today), licensed MIT. It adds 105 tokens to every session and 2,544 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 1 finding (runs shell commands). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other agents, from other repositories
angular-patterns
// Optional with default value readonly name = input ('').
nx-workflow
Purpose: Understanding the NX monorepo structure, development patterns, and best practices. For commands, see docs/internal/commands.md.
testing-guidelines
Agent "testing-guidelines" from SAP/fundamental-ngx, covering testing guidelines, test commands, run all tests in a library, run specific test file and examples.
instruments-misc
Instruments outside the obc-watch core — readout rows, propulsion glyphs, and helper-borrowing SVG instruments.
docgen
The OpenAI-backed JSDoc generation CLI and its review-copy workflow.
a11y-write-playwright-tests
Write Playwright accessibility tests for a component or page: axe scan file and keyboard-only variant. Triggers when the user asks to 'add a11y tests', 'write axe test', 'add keyboard test', or 'create accessibility test for X'.