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 skills add chrischall/compass-mcp --skill compass-fpxgit clone --depth 1 https://github.com/chrischall/compass-mcpWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/chrischall/compass-mcp/compass-fpx)<a href="https://agentmods.dev/skills/chrischall/compass-mcp/compass-fpx"><img src="https://agentmods.dev/badge/skills/chrischall/compass-mcp/compass-fpx/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/chrischall/compass-mcp/compass-fpx"><img src="https://agentmods.dev/badge/skills/chrischall/compass-mcp/compass-fpx.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00090 | $0.01362 |
| Opus 5 | $0.00045 | $0.00681 |
| Sonnet 5 | $0.00018 | $0.00272 |
| Haiku 4.5 | $0.00009 | $0.00136 |
Grade A, and why
compass-fpx 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 10d 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
plain `curl`/Node requests on some paths regardless of headers. `fpx` routes How it starts
The opening of the file, as written. The whole thing — 112 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Compass via fpx (no MCP)
Compass has no public JSON data-API for search/listing/agent data — it's a
fully server-rendered React app that embeds each page's data as JSON inside
an inline <script> global (global.uc, window.__INITIAL_DATA__,
window.__AGENT_PROFILE__). compass.com also runs AWS WAF, which 403s
plain curl/Node requests on some paths regardless of headers. fpx routes
every request through the user's own signed-in browser tab (the fetchproxy
extension), which already carries a cleared WAF session, so the page renders
normally — you then pull the JSON out of the HTML yourself.
This is Bucket 1 (full-fetchproxy): every call, not just an auth
bootstrap, rides the bridge. Compass validates at the session level per
request, same as the compass-mcp server itself (no server-side path
exists). No Compass login is required beyond having a signed-in tab open —
search/listing/agent data and the address-typeahead endpoint are all public.
One-time setup
npm install -g @fetchproxy/cli # provides `fpx`
fpx profile add compass --domain compass.com
fpx pair -p compass # prints a pair code → approve in the fetchproxy extension
Requirements: the fetchproxy browser extension installed, an open
www.compass.com tab, and its Chrome Site access allowing compass.com.
Pairing persists — after the first approval every later fpx call reuses it.
Core call pattern
Two request shapes:
- SSR pages (search, homedetails, agent profile) —
fpx getthe path, then pull the inline JSON global out of the HTML. - The one structured endpoint (address typeahead) —
fpx post-json.
fpx get 'https://www.compass.com/homes-for-sale/manhattan-ny/' -p compass > /tmp/page.html
node references/extract-global.mjs /tmp/page.html uc | jq '.sharedReactAppProps.initialResults.lolResults.data | length'
references/extract-global.mjs is a small, dependency-free re-implementation
of the balanced-brace walk compass-mcp's own src/page-state.ts uses
(extractGlobalAssign) — Compass writes each global as a JSON literal
(global.uc = {...};), so once the object is sliced out, JSON.parse/jq
works normally. Regexing for it without brace-balancing breaks the moment a
nested value contains }.
What ships with it
2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 10d ago First seen · 112 lines · 90 tokens per session scan A cd71568055b1
compass-fpx is a skill published in the GitHub repository chrischall/compass-mcp (0 stars, last pushed yesterday), licensed MIT. It adds 90 tokens to every session and 1,362 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
Other skills, from other repositories
systematic-debugging
Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.
local-ai-agents
Build local-first AI agents that run entirely on a developer workstation with Microsoft Foundry Local and Qwen function-calling models. Covers Small Language Models (SLMs), the OpenAI-compatible local endpoint, sandboxed local tools, local RAG with Chroma, local MCP servers, hybrid cloud/local routing, and the…
next-cache-components-adoption
Turn on Cache Components in a Next.js app and resolve the blocking routes it surfaces. Use when the user wants to enable, adopt, or migrate to Cache Components, flip the cacheComponents flag, work through a flood of blocking-prerender / instant validation errors, run the cache-components-instant-false codemod, or…
insight-error-page
Write or audit an insight-kind error page for the Next.js dev overlay. Use when creating a new errors/ .mdx page, auditing an existing one, or checking that a page matches the framework fix cards. Covers page structure, title alignment, FixCard cards with Copy prompt button, code snippets, terminology verification…
next-cache-components-optimizer
Drive a Next.js route to instant navigation by setting up an agentic loop, under Cache Components / PPR, on initial load (hard navigation) and client-side navigation (soft navigation). Encode the goal as a failing @next/playwright instant() e2e and work it to green, one verified route at a time; the shipped test then…
next-partial-prefetching-adoption
Turn on Partial Prefetching in a Next.js app and work through the insights it surfaces. Use when the user wants to enable or adopt Partial Prefetching, flip the partialPrefetching flag, opt routes in with export const prefetch = 'partial', audit Link prefetch={true} behavior, preserve existing prefetched UI with…