mcpField

Skills

100,928 packaged capabilities and playbooks for agents. Install any of them with one command.

All

A
aiden-review-pr
supatest-ai / alan-skills

Aiden's official agent skills—install across Claude Code, Codex, Cursor, Gemini CLI, OpenCode, and other SKILL.md-compatible agents.

Testing & quality324
A
aiden-review-pr
aiden-review-pr
tryalan-ai / alan-skills

No description yet

Other324
A
angular-best-practices-rule-creator
angular-best-practices-rule-creator
alfredoperez / angular-best-practices

For contributors to angular-best-practices. Creates new rule files and library skills following project conventions. Not for Angular application development — install angular-best-practices instead

Agent workflows324
A
astro-code-review
astro-code-review
withastro / astro

Perform a static, read-only code review of an Astro pull request or of a local branch, commit range, diff, patch, or working tree being prepared as a pull request. Determine whether the change satisfies its stated business requirements and is good enough to merge, using the PR description, linked requirement issues and roadmap items, and PR or issue discussions when available. Use this skill only for PR review or self-review, not issue triage or bug investigation. It reports only merge-relevant findings and never edits code or runs project code, tests, builds, checks, or scripts.

Testing & quality324
A
ati-tech-autotest-skill

No description yet

Testing & quality324
A
atlassian
atlassian
sanjay3290 / ai-skills

Manage Jira issues and Confluence wiki pages in Atlassian Cloud. Use when: (1) searching, creating, or updating Jira issues with JQL; (2) searching, reading, or creating Confluence pages with CQL; (3) managing Jira workflows, transitions, and comments; (4) browsing Confluence spaces and page hierarchies. Supports OAuth 2.1 via MCP server (recommended) or API token authentication (fallback).

Productivity324
A
azure-app-service
azure-app-service
microsoftdocs / agent-skills

Expert knowledge for Azure App Service development, including troubleshooting, best practices, decision-making, architecture and design patterns, limits and quotas, security, configuration, integrations and coding patterns, and deployment. Use when using deployment slots, ASE/VNet integration, managed identity/Key Vault, CI/CD, or OpenTelemetry sidecars, and for other Azure App Service development tasks. Not for Azure Functions (use azure-functions), Azure Container Apps (use azure-container-apps), Azure Kubernetes Service (AKS) (use azure-kubernetes-service), or Azure Static Web Apps (use azure-static-web-apps).

Cloud & DevOps324
B
bitrix-sessions
bitrix-sessions
bxmaximum / bitrix-framework-skills

Use for Bitrix sessions: Application::getSession(), getLocalSession(), parallel AJAX, and locking. Covers storage, BX_SECURITY_SESSION_READONLY, and split mode.

Development324
B
bmad-checkpoint-preview
bmad-checkpoint-preview
bmad-code-org / bmad-method

Deprecated: forwards to bmad-walkthrough. Do not use unless invoked by name

Development324
B
bmad-edit-prd
bmad-edit-prd
bmad-code-org / bmad-method

Deprecated — forwards to bmad-prd (update intent)

Development324
B
brand-voice
brand-voice
anthropics / knowledge-work-plugins

Apply and enforce brand voice, style guide, and messaging pillars across content. Use when reviewing content for brand consistency, documenting a brand voice, adapting tone for different audiences, or checking terminology and style guide compliance.

Marketing & growth324
B
bugcrowd-reporting
bugcrowd-reporting
elementalsouls / claude-bughunter

Bugcrowd-specific reporting tactics complementing report-writing: VRT category search-and-fallback strategy when no exact match exists, manual severity override when VRT defaults underrate impact, severity-request paragraph as first body section, OOS-clause rebuttal templates (rate limiting on auth-flow endpoints, debug-info framing, user-enumeration with sensitive PII, theoretical-issue counter), chained-finding cross-reference patterns, target selection for QA-vs-prod programs, researcher-side hygiene (Bugcrowdninja email alias, account state restoration, friendly-tester posture). Use when filing a Bugcrowd submission, when VRT default seems wrong, when triager closes as OOS or downgrades severity, when chaining linked submissions, or when scope distinguishes production from QA. Pairs with report-writing and triage-validation.

Security324
C
canvas-week-plan
canvas-week-plan
vishalsachdev / canvas-mcp

Student weekly assignment planner for Canvas LMS. Shows all due dates, submission status, grades, and peer reviews across all courses. Use when a student says "what's due", "plan my week", "weekly check", or wants to organize their coursework.

Productivity324
C
cloudflare-workers-frameworks
cloudflare-workers-frameworks
secondsky / claude-skills

Framework integration for Cloudflare Workers. Use when building with Hono, Remix, Next.js, Astro, SvelteKit, Qwik, or Nuxt on Workers. Covers routing, SSR, static assets, and edge deployment.

Development324
C
codenavi
codenavi
tech-leads-club / agent-skills

Your pathfinder for navigating unknown codebases. Investigates with precision, implements surgically, and never assumes — if it doesn't know, it says so. Maintains a .notebook/ knowledge base that grows across sessions, turning every discovery into lasting intelligence. Summons available skills, MCPs, and docs when the mission demands. Use when fixing bugs, implementing features, refactoring, investigating flows, or any development task in unfamiliar territory. Triggers on "fix this", "implement this", "how does this work", "investigate this flow", "help me with this code". Do NOT use for greenfield scaffolding, CI/CD, or infrastructure provisioning.

Development324
C
consumer-goods-tpe-dashboard-custom-kpi-configure
consumer-goods-tpe-dashboard-custom-kpi-configure
forcedotcom / sf-skills

Customize the Trade Promotion Effectiveness (TPE) Analytics dashboards' generic KPI slots (Promotion Measure 1-3, Tactic Measure 1-2) with customer-chosen KPI measure codes and display names, without touching the shipped base model. Use when a customer/admin wants to \"customize TPE dashboards\", \"change the KPIs on the Promotion/Tactic Analysis dashboard\", or \"swap in our own measure codes on the TPE dashboard\"

Data & databases324
C
control-ui-e2e
control-ui-e2e
openclaw / openclaw

Control UI browser tests, visual reviews and recordings, interaction performance audits, and Run Inspector evidence.

Testing & quality324
C
copy-editing
copy-editing
boraoztunc / skills

When the user wants to edit, review, or improve existing marketing copy. Also use when the user mentions 'edit this copy,' 'review my copy,' 'copy feedback,' 'proofread,' 'polish this,' 'make this better,' or 'copy sweep.' This skill provides a systematic approach to editing marketing copy through multiple focused passes.

Marketing & growth324
D
decision-toolkit
decision-toolkit
glebis / claude-skills

Generate structured decision-making tools — step-by-step guides, bias checkers, scenario explorers, and interactive dashboards. Use when facing significant choices requiring systematic analysis. Supports multiple cognitive styles and output formats.

Productivity324
D
designing-email-templates
designing-email-templates
posthog / skills

Author, save, and edit email templates in the PostHog workflows library—compose email design JSON with Liquid personalization and create and round-trip edit templates over MCP. Use when asked to design, build, update, or fix an email template for workflows, broadcasts, or campaigns

Marketing & growth324
D
device-interaction
device-interaction
tartinerlabs / skills

Verify app behavior on a device via screenshots, UI hierarchy, and touch interactions.

Testing & quality324
D
doc-reader

Read and navigate external documentation efficiently. Invoke when the task requires checking how a specific function, endpoint, or configuration option works; when the user references an API, SDK, library, or third-party tool by name; when any docs URL or documentation site is mentioned; or when implementing something that depends on an external service or package.

Development324
D
docx
docx
guanyang / open-agent-hub

Use this skill whenever the user wants to create, read, edit, or manipulate Word documents (.docx files) or Word templates (.dotx files). Triggers include: any mention of 'Word doc', 'word document', '.docx', '.dotx', or requests to produce professional documents with formatting like tables of contents, headings, page numbers, or letterheads. Also use when extracting or reorganizing content from .docx or .dotx files, inserting or replacing images in documents, performing find-and-replace in Word files, working with tracked changes or comments, or converting content into a polished Word document. If the user asks for a 'report', 'memo', 'letter', 'template', or similar deliverable as a Word or .docx file, use this skill. Do NOT use for PDFs, spreadsheets, Google Docs, or general coding tasks unrelated to document generation.

Documents324
D
dossier
dossier
alirezarezvani / claude-skills

Use for diligence or meeting prep on a specific company, person or organization ('prep me for a meeting with X', 'due diligence on Y'). Tests the user's stated hypothesis with balanced evidence (disconfirming_evidence_balance.py) and writes a .docx dossier.

Productivity324
E
energetic
energetic
bergside / awesome-design-skills

Dynamic, vibrant style with thick borders, geometric shapes, high-contrast colors, and expressive typography conveying motion and vitality

Design & UI324
F
fivem-development
fivem-development
proelias7 / fivem-skill

FiveM development best practices for any framework (vRP, QBCore, Qbox, ESX). Covers performance, security, client/server communication, cache (cacheaside + client-side cache §2.1.1), cerberus (load balance, SafeEvent, SetCooldown), view-cache audit (audit-passes.md §2.4), client-callable endpoint exposure & server auth (§5.1), input validation (§5.3), quality gates for implementation/refactor (quality-gates.md), asset discovery, framework auto-detection, and dynamic documentation fetching. Use when the user works with FiveM, Lua scripts, natives, resources, fxmanifest, optimization, /fxmind audit, or general server development without a specific framework context.

Development324
G
git-advanced
git-advanced
geoffjay / claude-plugins

Advanced git operations including complex rebase strategies, interactive staging, commit surgery, and history manipulation. Use when user needs to perform complex git operations like rewriting history or advanced merging

Development324
H
hunt-api-misconfig
hunt-api-misconfig
elementalsouls / claude-bughunter

Hunt API security misconfiguration — mass assignment, prototype pollution, HTTP verb tampering. Mass assignment: send {is_admin:true, role:admin, verified:true} on profile/account/reset endpoints — server blindly applies. JWT signature/crypto forging (alg:none, key confusion, kid/jku) is owned by hunt-jwt-crypto; this skill covers only non-crypto JWT handling. Prototype pollution: __proto__ injection in JSON merge / Object.assign / lodash _.merge → polluted prototype reaches sink (RCE in Node, XSS in browser). HTTP verb: GET-bypass-CSRF, X-HTTP-Method-Override, TRACE enabled. Detection: API responses with extra fields, JWTs in headers (decode at jwt.io). CORS misconfiguration (reflect-any-origin, null origin, subdomain-regex bypass, postMessage) is owned by hunt-cors. Use when hunting API misconfigs, mass-assignment, prototype pollution (JWT crypto → hunt-jwt-crypto).

Security324
H
hz-immersive-designer
hz-immersive-designer
meta-quest / agentic-tools

Guides design of comfortable, intuitive VR/MR experiences for Meta VR and Horizon OS — comfort guidelines, interaction patterns, spatial layout, accessibility. Use during UX design review or when evaluating comfort and accessibility. Build paths: Meta Spatial SDK, Unity, Unreal, native OpenXR, and WebXR; for 2D panel apps use hz-panel-designer if available. Use hz-quest-verify-first if the build path is unclear.

Design & UI324
I
image-batch
image-batch
guia-matthieu / clawfu-skills

Batch process images for marketing. Use when: resizing images for social media; compressing images for web; removing backgrounds; adding watermarks; converting formats to WebP; optimizing for Core Web Vitals

Creative & media324
K
kicad-bom
kicad-bom
american-embedded / kistack

Resolve and review exact PCB parts, packages, electrical ratings, availability, and manufacturer BOM fields for KiCad projects.

Other324
L
linkfox-temu-ads-us
linkfox-temu-ads-us
linkfox-ai / linkfox-skills

Temu US e-commerce Ads API, routed through the LinkFox gateway to Partner US Ads and related bg/temu ad-placement interfaces (campaigns, ad groups, creatives, reports, budgets, bids, etc.; interfaces will be integrated one by one according to Partner documentation). Trigger when the user mentions Temu US ads, Ads, ad placement, campaigns, ad groups, creatives, bids, budgets, ad reports, ad campaign, or product-inventory ads. For product management, use linkfox-temu-manage-product-us; for promotions, use linkfox-temu-promotion-us; for orders, use linkfox-temu-order-us.

Marketing & growth324
L
linkfox-temu-cancel-order-eu
linkfox-temu-cancel-order-eu
linkfox-ai / linkfox-skills

Temu Europe order cancellation API for buyers and sellers, routed through the LinkFox gateway to Partner EU. Covers buyer after-sales cancellations (bg.aftersales.cancel.*), seller appeals and out-of-stock cancellations (temu.order.cancel.*), and more. Trigger when the user mentions Temu EU order cancellation, buyer cancellations on the Europe site, seller out-of-stock cancellations, afterSalesStatusGroup, applySn, or site=eu order-shipping. For orders, use linkfox-temu-order-eu; for the US site, use linkfox-temu-cancel-order-us; for the global site, use linkfox-temu-cancel-order-global.

Other324
L
linkfox-temu-cancel-order-global
linkfox-temu-cancel-order-global
linkfox-ai / linkfox-skills

Temu global (non-US/EU) order cancellation API for buyers and sellers, routed through the LinkFox gateway to six interfaces: buyer after-sales cancellations (bg.aftersales.cancel.*), seller appeals and out-of-stock cancellations (temu.order.cancel.*), and more. Defaults to site=global and tokenPurpose=order-shipping. Trigger when the user mentions Temu Global order cancellation, buyer cancellations on the global site, seller out-of-stock cancellations, afterSalesStatusGroup, or applySn. For the US site, use linkfox-temu-cancel-order-us; for Europe, use linkfox-temu-cancel-order-eu; for orders, use linkfox-temu-order-global.

Other324
L
linkfox-temu-fulfillment-global
linkfox-temu-fulfillment-global
linkfox-ai / linkfox-skills

Temu global (non-US/EU) e-commerce fulfillment and shipping API: 23 interfaces covering Buy-Shipping label purchasing, partner warehouse fulfillment, seller-fulfilled shipping, and tracking (excluding Scan Form). Trigger when the user mentions Temu Global shipping, label purchasing, Buy-Shipping, partner warehouses, seller-fulfilled shipping, tracking, shipment.create, or site=global order-shipping. For orders, use linkfox-temu-order-global. For Scan Form, use linkfox-temu-fulfillment-us.

Other324
L
linkfox-temu-manage-product-eu
linkfox-temu-manage-product-eu
linkfox-ai / linkfox-skills

Temu Europe Manage Product API, routed through the LinkFox gateway to 24 Partner EU bg.local/temu.local interfaces: product lists/details/SKU lookup, partial or full edits, deletion, inventory, listing/unlisting, presales, category prechecks, attribute templates, compliance, external codes, video covers, and more. Trigger when the user mentions Temu EU Manage Product, Temu Europe product management, bg.local.goods, Partner EU, listing or unlisting products on site=eu, inventory updates, product deletion, or compliance edits. For promotions, use linkfox-temu-promotion-eu; for ads, use linkfox-temu-ads-eu; for pricing, use linkfox-temu-price-eu.

Other324
L
linkfox-temu-promotion-global
linkfox-temu-promotion-global
linkfox-ai / linkfox-skills

Temu global e-commerce promotion API, routed through the LinkFox gateway to Partner Global Promotion and related bg/temu interfaces (campaign creation, enrollment, lookup, coupons, flash sales, etc.; interfaces will be integrated one by one according to Partner documentation). Trigger when the user mentions Temu Global promotions, promotional campaigns, coupons, flash sales, campaign enrollment, promotion campaign, or product-inventory promotions. For product management, use linkfox-temu-manage-product-global; for pricing, use linkfox-temu-price-global; for orders, use linkfox-temu-order-global.

Marketing & growth324
L
llm-wiki
llm-wiki
akillness / jeo-skills

Build and maintain a persistent markdown wiki that an LLM updates on the user's behalf, usually inside an Obsidian vault or git-tracked notes repo. Use when raw sources such as web articles, papers, meeting notes, transcripts, screenshots, or past analyses need to be turned into an interlinked knowledge base with immutable source files, LLM-written wiki pages, `index.md`, `log.md`, schema rules in `AGENTS.md` or `CLAUDE.md`, source summaries, query notes, and recurring lint passes. Triggers on: llm-wiki, personal wiki, obsidian wiki, research vault, knowledge base, source ingest, persistent notes, wiki maintenance, source summaries, query filing

Productivity324
L
ln-625-dependencies-auditor
ln-625-dependencies-auditor
levnikolaevich / claude-code-skills

Checks outdated packages, unused deps, reinvented wheels, CVE/CVSS vulnerability scan. Use when auditing dependencies.

Testing & quality324
M
make-app-runtime
make-app-runtime
qfeius / make-platform-skills

Use when generating, refactoring, reviewing, or debugging Make App project runtime structure, workspace manifests, Service runtime, local/dev scripts, build outputs, Docker/K8s image entrypoints, publish readiness, or packaging errors such as missing `apps/service/dist/server.js`. Covers `apps/` workspace contracts, `apps/ui/dist`, `apps/service` port/build/start contracts, runtime config file location, runtime artifact tests, forwarded host/proto header preservation, and publish gates that include auth, default Trace ID, and applicable permission audits. Does not cover UI layout, authentication implementation, Trace behavior, permission logic, Make adapter env semantics, DSL modeling, Make CLI resource deployment, or canvas-table internals.

Cloud & DevOps324
M
modernize-tests
modernize-tests
tartinerlabs / skills

Migrate XCTests and XCUIAutomation suites to Swift Testing, and update existing Swift Testing tests to recommended patterns. Use when working with XCTest, XCUIAutomation, or when improving existing #expect/#require, @Test, and @Suite code

Testing & quality324
M
multi-agent-patterns
multi-agent-patterns
guanyang / open-agent-hub

This skill should be used when designing multi-agent systems that need context isolation, supervisor or swarm coordination, explicit handoffs, parallel execution, or a decision on whether multiple agents are justified.

Agent workflows324
M
multi-step-form-design
multi-step-form-design
rampstackco / claude-skills

Designing forms with multiple steps, progress indicators, conditional logic, and save-and-resume mechanics. The discipline of breaking complex data collection into stages that respect cognitive load while maintaining completion intent. Honest about kitchen-sink-single-page (overwhelms before the user starts), progress-theater (steps without genuine staging), and genuinely-staged (each step earns its own page) patterns. Triggers on multi-step form, multi-page form, form wizard, signup wizard, lead form, application form, intake form, configurator, onboarding form. Also triggers when a long form is converting poorly, when an audience is dropping off mid-form, or when a multi-step form is being scoped for the first time.

Design & UI324
O
opencv
opencv
tondevrel / scientific-agent-skills

Open Source Computer Vision Library (OpenCV) for real-time image processing, video analysis, object detection, face recognition, and camera calibration. Use when working with images, videos, cameras, edge detection, contours, feature detection, image transformations, object tracking, optical flow, or any computer vision task.

Data & databases324
O
operations-manager
operations-manager
borghei / claude-skills

Operations management across process optimization, efficiency, and continuous improvement. Use when designing workflows, building capacity plans, evaluating vendors, running Lean Six Sigma DMAIC projects, or optimizing cost-per-unit.

Other324
P
penpot-mcp
penpot-mcp
ar27111994 / penpot-mcp

Use this skill whenever the user wants to use AI agents to work with Penpot design files via the Penpot MCP Server. Triggers include: using Penpot through an AI agent, design files, design systems, design tokens, Penpot MCP, design-to-code, generating UI from design, auditing a design system, creating components/variants, renaming layers, exporting assets from Penpot, adding flows, interactions, animations, overlays, or prototyping in Penpot, or prompting an AI agent to read/modify a Penpot file. Also triggers when the user wants to set up Penpot MCP, connect any MCP-compatible AI agent or IDE to Penpot, or produce production-ready HTML/CSS/React from a Penpot design. Use this skill for Penpot-agent workflows — design, code, audit, prototyping, or setup.

Design & UI324
P
pine-visualizer
pine-visualizer
traderspost / pinescript-agents

Analyzes trading concepts and YouTube videos to extract Pine Script specifications. Use when planning indicators or analyzing video tutorials

Development324
R
resource-curator
resource-curator
leonardomso / 33-js-concepts

Find, evaluate, and maintain high-quality external resources for JavaScript concept documentation, including auditing for broken and outdated links

Productivity324
R
rw-generate-image
rw-generate-image
runwayml / skills

Generate images directly using the Runway API via runnable scripts. Supports text-to-image with optional reference images.

Creative & media324
S
script-components
script-components
decentraland / sdk-skills

Write .ts script files for the Creator Hub Script component — self-contained classes attached to individual entities. Use when the user wants to create a custom smart item, a reusable scripted entity, or write code that runs on a Creator Hub Script component. Do NOT use for regular scene index.ts code or global systems (see scene-runtime, add-interactivity).

Development324
S
self-improving-agent

Captures and maintains learnings, errors, and corrections. Use when a command fails, the user corrects an assumption, a capability is missing, knowledge is outdated, or a better approach is found. Review relevant saved guidance before major tasks, reuse, and promotion; revalidate it according to what could change and how quickly.

Agent workflows324
S
skillify
skillify
garrytan / gstack

Codify the most recent successful /scrape flow into a permanent browser-skill on disk. (gstack)

Agent workflows324
S
spark-recipe-shared-inbox-triage
spark-recipe-shared-inbox-triage
readdle / spark-cli-skills

Process open items in shared inboxes: review, assign, respond, or mark done

Productivity324
S
spree-catalog
spree-catalog
spree / agent-skills

Use when the user is working with the Spree 6 product catalog — products, variants, option types/values, the default variant, product types (templates), categories vs collections, custom fields, media (images, video, media library), channel publications, search providers (database, spree_meilisearch, custom), digital assets, or catalog imports/exports. Common phrasings include "create a product", "add variants", "size and color options", "product type", "category tree", "collection", "brand", "custom field on products", "product images", "product video", "primary_media", "product not showing in store", "publish product on channel", "Meilisearch", "reindex", "custom search provider", "digital download", "master variant". Covers the catalog graph and how to read/write it from Ruby, the Admin SDK and `spree api`

Development324
T
tavily

Tavily API integration with managed API key authentication. Perform AI-powered web search, extract content from URLs, crawl websites, map site structure, and run research tasks. Use this skill when users want to search the web, extract page content, crawl websites, discover URLs, or conduct in-depth research with citations. For other third-party apps, use the api-gateway skill (https://clawhub.ai/byungkyu/api-gateway). Requires network access and a valid Maton API key.

Productivity324
T
thesvg
thesvg
glincker / thesvg

Fetch brand SVG logos and cloud architecture icons (AWS, Azure, GCP) from theSVG. Use when the user asks for a brand logo, company icon, framework mark, service icon, or any "icon/logo for X" where X is a real brand or cloud service. Returns ready-to-use CDN URLs or raw SVG markup

Design & UI324
T
tweet-writer
tweet-writer
sanky369 / vibe-building-skills

Write high-engagement tweets and X/Twitter threads, grounded in live research of what's currently working in the user's niche: researches viral examples via web search, then drafts hook variants, a single-tweet version, and a thread version with alternates to test. Use when the user says 'write a tweet about X', 'turn this into a thread', 'help me go viral', 'grow my X/Twitter account', 'my tweets get no engagement', or shares an idea/article to tweet — any X/Twitter content request. Produces a Tweet Package: 3 hook options, final single tweet, full thread, and posting notes.

Marketing & growth324
V
video-script
video-script
indranilbanerjee / digital-marketing-pro

Write a video script: hooks, timestamped dialogue, visual cues. Title/thumbnail → video-packaging. "write a YouTube script about X"

Marketing & growth324
V
vue-router-skilld
vue-router-skilld
skilld-dev / vue-ecosystem-skills

ALWAYS use when writing code that imports "vue-router", "vue-router/vite", "vue-router/auto-routes", or "vue-router/experimental". Consult for debugging, best practices, or modifying vue-router, vue router, router, file-based routing, typed routes, data loaders.

Development324
A
accelint-security-best-practices
accelint-security-best-practices
gohypergiant / agent-skills

Comprehensive security audit and vulnerability detection for JavaScript/TypeScript applications following OWASP Top 10. Use when (1) users say 'audit security', 'check for vulnerabilities', 'security review', 'implement authentication', or 'secure this code'; (2) adding authentication, API endpoints, file uploads, or handling user input; (3) working with secrets, credentials, or sensitive data; (4) implementing payment features or blockchain integrations; (5) conducting pre-deployment security checks. Audits for hardcoded secrets, injection vulnerabilities, XSS/CSRF, broken access control, insecure authentication, rate limiting, dependency vulnerabilities, and sensitive data exposure.

Security323
27421–27480 of 100,928

New to MCP?

From what the protocol is to installing your first server, these answers cover most first questions.

An open protocol that defines how AI applications connect to external tools and data in a uniform way. Clients talk to the model; MCP servers provide tools, resources and prompt templates. They exchange standard messages, so one server can be reused by many clients.