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Slipstream agent · Web

Site Auditor

A Lighthouse page audit agent for Claude Code, Codex and Cursor

Site Auditor runs Lighthouse, axe-core included, on one public web page and ranks the fixes by the score each would add. No price is set for this version yet.

Not offered in ContextStream yet. It runs only on Slipstream's own API, which is not open for accounts. Version 1.0.0 · Updated

What does Site Auditor do?

Runs Lighthouse and axe-core on a public web page and ranks the fixes by what each would add to its performance, accessibility, best-practices or SEO score.

What it declines

A task like one of these is declined with a reason, and a declined run is free:

  • Changing the site, or writing its code.
  • Pages behind a login, private networks, or anything that is not a web page.
  • Crawling a whole site, load testing or security scanning.

What does a real run of Site Auditor look like?

The input, the result (shortened where it is long), how long it took, what it cost and where it ran. Live runs used public or demo material only; a run marked as from the eval suite is not a live run.

Live run on Slipstream's own API

contextstream.io on a phone

Version
1.0.0
Outcome
succeeded
Ran
2026-10-27 17:18 UTC
Took
12.0 s
Cost
No charge (no model, not billed)

Slipstream's own API on a Depot CI runner, inside the images/base.Dockerfile image as an unprivileged user. No model, no ContextStream, no credits.

Input
{
  "url": "https://contextstream.io/",
  "form_factor": "mobile",
  "also_allow": [
    "ph.contextstream.io",
    "static.cloudflareinsights.com"
  ],
  "max_fixes": 8
}

Result

Performance 94, accessibility 92, best practices 81, SEO 100 (mobile). Top fix: Uses deprecated APIs (+19.2 best-practices points). 5 fixes ranked.

Lighthouse 13.5.0 scores (mobile)

PerformanceAccessibilityBest practicesSEO
949281100

Metrics

  • First contentful paint 2052 ms
  • Largest contentful paint 2658 ms
  • Total blocking time 90 ms
  • Cumulative layout shift 0.009

Fixes worth the most points

FixCategoryPointsSeverityWhy
Uses deprecated APIsbest-practices19.2highDeprecated APIs will eventually be removed from the browser.
Background and foreground colors do not have a sufficient contrast ratio.accessibility3.9mediumLow-contrast text is difficult or impossible for many users to read.
Links do not have a discernible nameaccessibility3.9mediumLink text (and alternate text for images, when used as links) that is discernible, unique, and focusable improves the navigation experience for screen reader users.
Render-blocking requestsperformance2.3lowRequests are blocking the page's initial render, which may delay LCP. Deferring or inlining can move these network requests out of the critical path.
Improve image deliveryperformance0.8lowReducing the download time of images can improve the perceived load time of the page and LCP.

report.md

# Site audit: https://contextstream.io/

Performance 94 · Accessibility 92 · Best practices 81 · SEO 100 (mobile, Lighthouse 13.5.0)

## Fixes, highest impact first

1. **Uses deprecated APIs** (best-practices; +19.2 points; high)
   Deprecated APIs will eventually be removed from the browser.
2. **Background and foreground colors do not have a sufficient contrast ratio.** (accessibility; +3.9 points; medium)
   Low-contrast text is difficult or impossible for many users to read.
   - div.st-panel-body > div.st-rec > div.st-rec-meta > span.st-k-dim <span class="st-k-dim">
   - div.st-panel-body > div.st-rec > div.st-rec-meta > span.st-k-dim <span class="st-k-dim">
   - div.st-panel-body > div.st-rec > div.st-rec-meta > span.st-k-dim <span class="st-k-dim">
3. **Links do not have a discernible name** (accessibility; +3.9 points; medium)
   Link text (and alternate text for images, when used as links) that is discernible, unique, and focusable improves the navigation experience for screen reader users.
   - div > header.st-header > nav.st-nav > a.st-brand <a class="st-brand" href="/" aria-current="page">
4. **Render-blocking requests** (performance; +2.3 points; low)
   Requests are blocking the page's initial render, which may delay LCP. Deferring or inlining can move these network requests out of the critical path.
   - https://contextstream.io/_next/static/css/87a7c575a27749d7.css
   - https://contextstream.io/_next/static/css/d784aaf17c102fbc.css
   -
…
Checks: 3 of 4 passed
  • performance: 94 of 100.
  • accessibility: 92 of 100.
  • best practices: 81 of 100.
  • seo: 100 of 100.
  • The first run (performance 69) reported a host the page loads that was not allowed; this second run allows it with also_allow, as the first one suggested.
Run
run_db42961759c8e34f13
Depot run
0zb9r381xr
Image
images/base.Dockerfile@3a1adeda3695 (slipstream origin/main) + scripts/example-runs from branch site-example-runs 5112d5b (local)
Sandbox
the fake provider on loopback, inside that disposable container

What does Site Auditor cost?

Site Auditor has no price yet for version 1.0.0, and ContextStream does not offer it yet.

Which tools does Site Auditor work with?

Claude Code, Codex, Cursor and other MCP clients, once ContextStream offers it: through the slipstream tool of ContextStream's MCP, ss run site-audit in a terminal, or the web app. It runs only on Slipstream's own API, which is not open for accounts.

  • Claude Code, Codex, Cursor and other MCP clients: connect ContextStream's MCP once (setup for each editor), then ask your agent to hand the job to Site Auditor.
  • A terminal or an agent's shell: ss run site-audit, installed with ContextStream's command line.
  • The web app: the workspace's specialist library, where each run shows its price before it starts.

What access does Site Auditor need?

Site Auditor gets no ContextStream access at all: it runs in its own sandbox with no credentials inside, reaching only the hosts in your input.

Sandbox agent. A bundle that runs in its own isolated sandbox with no credentials inside and no model calls. Network: only the hosts named in your input. It is stopped after 5 min.

How do I turn Site Auditor on?

You cannot turn Site Auditor on yet: it runs only on Slipstream's own API, which is not open for accounts. It is built and tested, and its page shows how it will be called.

How do I call Site Auditor from Claude Code or Codex?

Once it is offered: ss run site-audit in a terminal, or slipstream(action="run", agent="site-audit", input={...}) over MCP, with the input below.

Connect ContextStream's MCP (it also writes each editor's connection):

curl -fsSL https://contextstream.io/scripts/mcp.sh | bash

A mobile audit of the home page, its fixes ranked. Over MCP:

slipstream(action="run", agent="site-audit", input={"url":"https://example.com/"})

In a terminal (curl -fsSL https://contextstream.io/cs/install.sh | sh installs ss):

ss run site-audit url=https://example.com/

Input

FieldTypeWhat it is
urlstring, requiredThe page to audit.
form_factor"mobile" | "desktop", requiredLighthouse's mobile or desktop settings.
also_allowstring[], requiredHosts the page loads from other than its own, such as its CDN. Requests to any other host are refused and reported.
max_fixesinteger, required
categories"performance" | "accessibility" | "best-practices" | "seo"[]All four by default.