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QuassLabs API

by Quasslabsversion 0.3.0i★ –iRuns in the cloud
Registry namecom.quasslabs/api

Install

Overview

Description from the maker (original English)

30+ deterministic dev and delivery tools: linting, metrics, diagrams, model advice, AI-text checks.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

  • Connection: Runs in the cloud
  • Transport: Streamable HTTP
  • Category: Design, images & audio
  • You need to fill in: Authorization

Install

Pick the AI app you use, then copy the settings.

Before you install

Values marked secret are keys to your account. Never share them or paste them into a chat.

You need

Which app do you use?

Pick your app above. We remember it, so next time the button says “Install in …”.

This address needs a key in a request header, which the add-connector menu cannot set. Use Claude Code, Cursor or VS Code instead.

Run this in your terminal

claude mcp add --transport http api https://api.quasslabs.com/mcp --header 'Authorization: your-value'

Fill in the empty values before running it.

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "api": {
      "url": "https://api.quasslabs.com/mcp",
      "headers": {
        "Authorization": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "api": {
      "type": "http",
      "url": "https://api.quasslabs.com/mcp",
      "headers": {
        "Authorization": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

This address needs a key in a request header, which the add-connector menu cannot set. Use Claude Code, Cursor or VS Code instead.

Your choice stays on this device in a cookie; no account needed.

Values you fill in

  • Authorization secret HTTP header
    Bearer qlk_... API key from https://quasslabs.com/api, or from the account tool's signup action (needed for tools/call, except account signup and checkout_status)

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Tool names and descriptions exactly as the server reported them on Nov 8, 2026. The maker wrote them, not us; we show them as plain text.

  • alignment_gate

    Run an AI system prompt (and optional agent config) through a 45-criterion alignment/safety rubric. Returns a letter grade (A-F), numeric score, per-flag remediation, and a pass/fail verdict.

  • blm_land_lookup

    Look up Bureau of Land Management land status for a US coordinate: BLM ownership, jurisdiction, allowed activities (rockhounding, camping), permit requirements, and special designations (ACEC, Wilderness, WSA, NM/NCA).

  • diagram_contrast

    Diagram quality QA. Catch and fix the things that ruin diagrams: (1) unreadable label contrast - POST a mermaid/SVG or HTML diagram, get every WCAG-AA failure (incl. mermaid -block label colors, with unresolvable fills flagged honestly, not false-passed) + auto-corrected colors;

  • humanizer_score

    Detect AI-writing tells in text. POST prose and get a 0-1 ai_ness score + band (low/medium/high) + the EXACT patterns that fired (AI vocabulary, significance inflation, promotional language, filler phrases, negative parallelism, rule-of-three, em-dash overuse) with sample spans.

  • saas_metrics

    SaaS health advisor. POST your MRR/customers (+ optional churn/CAC/margin/growth) and get ARR/ARPA/LTV/CAC/payback/Rule-of-40/NRR/GRR computed, each with a health tag, plus an overall grade + a ranked "what to fix first" focus list. Deterministic math + advisory, no LLM.

  • acceptance_criteria_validator

    QA advisor: validate acceptance criteria quality. POST a list of AC (or a story) and get per-AC problems (vague/untestable, non-atomic, no observable outcome) + a missing-coverage flag if there is no failure-path AC, plus a 0-100 score and pass/needs_work verdict. Tells you exact

  • coverage_check

    Scope-completeness advisor. POST a brief (or requirements[]) + your stories[] and get a coverage score + the gaps (requirements no story covers), orphan stories (possible scope creep), and missing structural buckets (auth/CRUD/error-states/tests). Tells you what the scope is miss

  • defect_triage

    Bug-triage advisor. POST one bug report (or a list) and get severity (critical/high/medium/low), category, whether it has repro steps, and what info is missing (no repro / no expected-vs-actual / no environment). For a list: priority ranking + likely-duplicate clusters. Determini

  • model_advisor

    LLM selection + cost advisor. POST a task description (+ optional volume/tokens/constraints like local-only or cheap) and get a recommended model + fallback chain + do-not-use (with reasons), the complexity tier, and per-run + monthly cost. A maintained model+price catalog. Deter

  • tool_advisor

    Which QL-API endpoint fits this task. POST a task description and get the ranked endpoint(s) that best match, each with a confidence label (high/medium/low). Deterministic keyword matching over this platform's own endpoint catalog, no LLM. Pairs with model_advisor (which itself i

  • humanize_text

    Rewrite text to remove AI-writing tells. POST prose and get it back with the mechanical tells fixed (AI vocabulary swapped for plain words, filler phrases stripped, em-dash overuse reduced, significance inflation deflated) plus a change log, before/after ai-ness scores, and a res

  • dependency_check

    Lint dependency manifests for hygiene: unpinned, wildcard or unbounded versions, missing lockfiles, git/URL deps, non-https indexes, install scripts, dependency-confusion names, plus a small static snapshot of famous compromised versions (not a live CVE feed). Use this for a few

  • log_audit_creator

    Generate a concrete audit-logging spec for an app. POST your feature list (and optional compliance targets: soc2/hipaa/gdpr/pci) and get a full audit-event catalog (namespaced event names, actor/target/required fields, PII flags, retention), a canonical event envelope schema, a s

  • log_analyzer

    Analyze a log file. POST raw log text (or an upload_id from the create_upload tool, up to 5MB) and get: level breakdown + time range, error clusters (messages normalized so variable ids/numbers collapse into one signature, with counts + first/last seen + a sample), a timeline, de

  • ticket_lint

    Full Jira-ticket quality linter (whole ticket, not just AC - use acceptance_criteria_validator for the deep AC pass). POST one ticket or a batch (max 50) and get per-ticket findings with severity + concrete fixes: missing/weak summary or description, missing AC or estimate, bugs

  • story_lint

    Deterministic structural quality linter for user stories - a sibling to ticket_lint but scoped to story-writing concepts any team recognizes: narrative completeness (As-a/I-want-to/So-that/Summary), acceptance criteria presence, duplicate/unknown dependency IDs, a "Manage X" stor

  • estimate_sanity

    Deterministic classifier for story/task hour estimates against benchmarks: flags each estimate in_range, borderline, over, under, or unbenchmarked. Supply either an explicit {min, max} range per type (benchmarks) or a list of historical actual hours per type (historical) that thi

  • pr_description_lint

    Deterministic PR description quality linter: flags a missing/too-short body, absent test evidence, absent stated rationale, an unstructured long body, and - only for PRs that look like bugfixes (title prefix fix/bug/hotfix/patch, or an explicit is_bugfix flag) - missing repro ste

  • commit_hygiene

    Deterministic commit-message hygiene checker: conventional-commit format, vague-subject detection, subject-length limit, a same-message secret-pattern scan (AWS keys, private key headers, Slack/GitHub tokens, inline password=/secret= style credentials - checked against the messag

  • readability_grade

    Deterministic Flesch Reading Ease and Flesch-Kincaid Grade Level for a block of text, plus word/sentence/syllable counts and a plain-language reading-ease band (very_easy through very_confusing). Syllable counting is the standard vowel-group heuristic (same approximation used by

  • regex_lint

    Static safety analysis of a regular expression plus an English explanation of what it matches. Parses the pattern into an AST and flags the structures that cause catastrophic backtracking (ReDoS): nested unbounded quantifiers like (a+)+, repeated alternations whose branches can s

  • mcp_tool_lint Looks like an instruction to the AI

    Static review of MCP tool definitions, as returned by a server's tools/list, for how well a model can choose and call them. Flags missing, too-short or vague descriptions; parameters with no description or type; free-form objects and arrays without items; required fields that are

  • openapi_diff

    Compares a base and a head OpenAPI 3.x spec (JSON object, or a JSON or YAML string) from the API consumer's point of view and lists what would break existing clients: removed operations or 2xx responses, new required parameters or request properties, optional-to-required changes,

  • sprint_health

    Sprint/delivery health advisor. POST 1-24 sprints (committed/completed points, optional per-ticket estimate-vs-actual data) and get computed metrics each with a good/warn/bad health tag: velocity avg + trend + stability, commitment reliability, spillover rate, mid-sprint scope ch

  • worklog_guardrail

    Worklog/timesheet policy checker - run a batch of worklog entries through configurable guardrails BEFORE posting them to a time-tracking system. Checks: rounding increment (default 0.25h, float-safe), per-entry min/max, per-author daily totals, duplicates, over-estimate alerts (n

  • create_upload

    Get a presigned S3 PUT URL to upload a file (policy doc, config, log, up to 5MB) that a file-ingesting endpoint then reads by upload_id. Two-step: call this, PUT your file to the returned url, then pass upload_id to the consuming endpoint. Uploads auto-expire in 1 day and are rea

  • send_feedback

    Submit free-text feedback about the API - a bug, an idea, a docs gap, a billing question, or anything else. Missing a tool? Use kind tool_request to tell us what you needed, with an optional tool_description. Tied to your key so we can follow up, but not a support-ticket SLA. Aut

  • account

    Everything about your QuassLabs API account, chosen by `action`. Free: no action costs credits. "signup" (no API key needed): request a free key for an email address. A confirmation link is emailed; a human opens it on quasslabs.com to see the key, which is never returned to the

  • rate_call

    Rate a specific prior metered call - thumbs up or down, plus an optional comment - keyed by the request_id that call's response reported. Works for any metered tool, so you can tell us when a result was wrong, unhelpful, or missed something. Resubmitting the same request_id overw

  • supply_chain_scan

    Scan a whole repo archive (a ZIP of manifests, lockfiles and MCP server configs) for packages, MCP servers and extensions listed in a known-compromise catalog (Bumblebee threat intel). Use this for a repo, many lockfiles or MCP configs; use dependency_check instead to lint a few

  • describe_diagram

    Turn a plain-English description into Mermaid diagram source. Describe the flow, system, schema or timeline you want ("a login flow with an OAuth branch and a failure path") and get back complete, valid Mermaid - no need to know the syntax. The mermaid field of the response is di

  • convert_diagram

    Make Mermaid diagrams portable. Takes HTML containing blocks (or a raw Mermaid source) and returns the same document with every diagram pre-rendered to inline SVG and the Mermaid CDN runtime stripped. A CDN-backed diagram only renders if the reader can fetch and run the runtime;

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 8, 2026

  • ✓ Pass

    Maker matches the repo

    The registry name was verified against the domain quasslabs.com (the registry checks domain ownership)

  • … Not checked yet

    Still maintained

    We have not read this repo from GitHub yet

  • … Not checked yet

    Has a licence

    We have not read this repo from GitHub yet

  • ✓ Pass

    Endpoint responds

    Responded in 668 ms (HTTP 200)

  • – Not applicable

    Sign-in with OAuth

    No sign-in needed

  • ✕ Fail

    No hidden instructions in tool descriptions

    1 tool descriptions contain text that looks like instructions to the AI. Read them below before installing

Compared with others in Design, images & audioi

  • More stars than 0% of the other 2789 servers in this category
  • Published to the registry more recently than 100% of the other 2789 servers in this category
  • Basic checks equal to or better than 44% of the other 2789 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is QuassLabs API safe?

It passed 2 of 3 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

You need to fill in: Authorization

Does it run on my computer or in the cloud?

It runs in the maker’s cloud. Connect over the internet with nothing to install, but what you send passes through the maker’s servers.

Is it still maintained?

The GitHub repo last changed –, and the latest version (0.3.0) reached the registry today.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. It connects by URL, so apps that accept remote MCP servers work too, such as ChatGPT in developer mode.

What can I use instead?

In the same category: Figma Context MCP, Claude Real Video, Figma MCP Server

Alternatives

Servers in the same category from other makers, sorted by stars.

Reading a card:↓ Downloads per weeki★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

Figma Context MCP

Give your coding agent access to your Figma data. Implement designs in any framework in one-shot.

by GLipsWidely used↓ 161.2K/wk★ 16.2KUpdated 5 months ago

Runs on your computer

Claude Real Video

Let any LLM watch a video locally — and search everything it has ever watched.

by HUANGCHIHHUNGLeoWidely used↓ 1.1K/wk★ 2.3KUpdated 2 months ago

Runs on your computer

Figma MCP Server

Figma’s official server gives AI your design data so it can turn designs into code or describe them accurately. Connects to Figma’s cloud.

by figmaGrowing★ 2.2KUpdated 13 months ago

Runs in the cloud✓ mcp.figma.com

README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

QuassLabs API — MCP server

32 deterministic developer and delivery tools over one authenticated MCP endpoint. No LLM in the loop for most of them: they are scorers, linters, validators and calculators, so results are reproducible and cheap. Covers prompt-safety grading, AI-writing detection and rewriting, LLM selection and cost advice, ticket/story/PR/commit linting, sprint and SaaS metrics, log analysis, dependency hygiene and supply-chain scanning, MCP tool linting, Mermaid diagram generation and offline rendering, and BLM land lookup.

Endpoint: https://api.quasslabs.com/mcp · Transport: streamable HTTP (stateless JSON-RPC 2.0) · Server version: 0.2.0

Documentation: https://docs.quasslabs.com

Connect

Every client sends the same thing: a Bearer qlk_... API key in the Authorization header. Hosts that reserve Authorization for themselves can send X-API-Key: qlk_... instead.

Claude Code

claude mcp add --transport http quasslabs https://api.quasslabs.com/mcp \

--header "Authorization: Bearer qlk_YOUR_KEY"

Cursor (~/.cursor/mcp.json, or .cursor/mcp.json in a project)

{

"mcpServers": { "quasslabs": { "url": "https://api.quasslabs.com/mcp", "headers": { "Authorization": "Bearer qlk_YOUR_KEY" } } } }

Any other client that supports streamable HTTP

{

"mcpServers": { "quasslabs": { "type": "http", "url": "https://api.quasslabs.com/mcp", "headers": { "Authorization": "Bearer qlk_YOUR_KEY" } } } }

Or call it directly:

curl -sS -X POST https://api.quasslabs.com/mcp \

-H 'Content-Type: application/json' \ -H 'Authorization: Bearer qlk_YOUR_KEY' \ -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"account","arguments":{"action":"balance"}}}'

Getting a key. Sign up at https://quasslabs.com/api, or from inside an agent with the account tool (action: "signup", no key needed). Either way you get an email with a one-time link, and the key is shown on quasslabs.com, never in the agent transcript. Every key gets 300 free credits each month.

Authentication

initialize, tools/list and ping are unauthenticated, so any client or registry can discover the catalogue without credentials. tools/call requires the API key, except the account tool's signup and checkout_status actions. Keys are stored only as a SHA-256 hash, so a lost key cannot be recovered, only revoked and reissued.

Pricing

Prepaid credits, 1 credit = $0.01:

PackPriceCredits
Starter$5500
Pro$202,500

Buy a pack from inside an agent with the account tool (action: "buy_credits" returns a Stripe Checkout link for a human to pay), and check what is left with action: "balance". Each key's free monthly credits are spent before purchased credits and refill on the first day of each UTC month.

Failed calls are not billed: a call rejected before the tool runs (bad input, missing key, rate limit, insufficient credits) costs nothing, and a call that fails on our side (any 5xx) is refunded automatically. That includes supply_chain_scan archives that download but are rejected (not a ZIP, an unsafe path, too many entries, or too large once extracted): the archive is checked before anything is charged. A convert_diagram call whose diagrams all fail to render (422 mermaid_render_failed) or whose output is over the size limit (413 output_too_large) is refunded too.

Tools (32)

Credits are per successful call. Tools marked 0 are free but still need a key.

Writing and prompts
ToolCreditsWhat it does
alignment_gate35Grade an AI system prompt against a 45-criterion alignment/safety rubric: letter grade, per-flag remediation, pass/fail
humanizer_score00-1 AI-ness score plus the exact patterns that fired
humanize_text1Rewrite prose to strip mechanical AI-writing tells
readability_grade0Flesch Reading Ease and Flesch-Kincaid Grade Level with a plain-language band
Engineering and security
ToolCreditsWhat it does
model_advisor0Recommended model, fallback chain, do-not-use list, and a cost comparison for a task
tool_advisor0Which of these tools fits a task, ranked with a confidence label and the MCP tool name to call
dependency_check0Lint pasted dependency manifests for hygiene: pinning, lockfiles, insecure sources, install scripts, dependency confusion
supply_chain_scan5Scan a whole repo ZIP (manifests, lockfiles, MCP server configs) against a known-compromise catalog
log_analyzer5Level breakdown, time range, and normalized error clusters from a raw log file (up to 5MB)
log_audit_creator5Feature list in, concrete audit-event catalog out, optionally targeted at SOC2/HIPAA/GDPR/PCI
regex_lint1ReDoS risk analysis plus a plain-English explanation of a regular expression; compiles the pattern but never runs it
mcp_tool_lint1Lint MCP tool definitions for model usability: vague descriptions, untyped parameters, near-duplicates, missing annotations, tool-poisoning phrases
openapi_diff1Breaking-change report between two OpenAPI 3.x specs (JSON or YAML), with the semver bump it needs
Delivery and QA
ToolCreditsWhat it does
ticket_lint1Whole-ticket quality linter with severity-coded findings, batched up to 50
story_lint1User-story structure: narrative completeness, atomicity, testability
acceptance_criteria_validator1Per-AC problems: vague/untestable, non-atomic, no observable outcome, missing coverage
coverage_check1Requirements-vs-stories coverage score, gaps, and orphan stories (scope creep)
defect_triage1Bug severity, category, repro-step presence, and what information is missing
sprint_health11-24 sprints in, health-tagged delivery metrics out
worklog_guardrail1Run timesheet entries through configurable policy guardrails before posting them
estimate_sanity1Classify story/task hour estimates against benchmarks: in-range, borderline, over, under
pr_description_lint1Missing body, absent test evidence, absent rationale, unstructured long body
commit_hygiene1Conventional-commit format, vague subjects, length limits, and a secret-pattern scan
Diagrams
ToolCreditsWhat it does
describe_diagram5Plain-English description in, Mermaid diagram source out
convert_diagram1Pre-render Mermaid to inline SVG so HTML works offline, in email, and in PDF exports
diagram_contrast0Diagram QA: every WCAG-AA label-contrast failure in a Mermaid/SVG/HTML diagram, with fixes
Data
ToolCreditsWhat it does
saas_metrics0ARR/ARPA/LTV/CAC/payback/Rule-of-40/NRR/GRR computed and health-tagged, plus an overall grade
blm_land_lookup8BLM land status for a US coordinate: ownership, allowed activities, permit requirements, special designations
Account and utilities
ToolCreditsWhat it does
account0One tool for your account. action: signup (email a one-time key link, no key needed), balance (credits, free credits left, reset date), buy_credits (Stripe Checkout link: $5 / 500 or $20 / 2,500), checkout_status (did a purchase land)
create_upload0Presigned S3 PUT URL so file-ingesting tools can read a document by upload_id
send_feedback0Submit a bug, idea, or docs gap against your key. Missing a tool? Send kind: "tool_request"
rate_call0Thumbs up/down a prior metered call by its request_id

tools/list only ever advertises what is callable right now. compress (LLMLingua-2 prompt compression, 10 credits) is built but temporarily switched off, so it is not listed.

Renamed in 0.2.0

humanize is now humanize_text, uploads is now create_upload, and feedback is now send_feedback. The REST endpoints (/v1/humanize, /v1/uploads, /v1/feedback) did not change.

Links

  • Documentation — https://docs.quasslabs.com
  • Privacy policy — https://quasslabs.com/privacy
  • Terms — https://quasslabs.com/terms
  • Homepage — https://quasslabs.com

About this repository

This repository is the public manifest for the QuassLabs API MCP server: the registry entry, the tool catalogue, and connection instructions. The server is a hosted remote endpoint, so there is nothing to install and no server source here. The platform implementation is a commercial product and is not open source.

Report a problem with the MCP server through the send_feedback tool (free), or see SECURITY.md for security reports.

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