Development MCP Servers

Pay-per-call MCP tools for agents, settled with x402 (USDC on Base mainnet). 17 tools — text/data utilities plus x402/EVM-native. No API keys.

Local stdio MCP server with eight bounded tools for Scala compilation, tests, compiler diagnostics, type/effect summaries, symbols, SemanticDB, and evidence reconciliation for AI coding agents.

LLM rankings fitted across public benchmarks: leaderboard, model profiles with Elo ± SE, head-to-head comparisons and source-linked benchmark scores. Free, no auth.

Lints MCP tool definitions for prompt-injection wording and hidden Unicode, and estimates their context cost. Offline, stdio, no dependencies.

Hosted MCP tools for tracking GitHub issue and Stripe test-payment outcomes, reconciling uncertain actions, and controlled retries. API-key authentication; free developer beta.

Pay-per-call marketplace of APIs and AI models for agents: one key for LLMs, web search, scraping, media and business data; compare providers on the same input.

Uptime monitoring from your AI agent: create and manage HTTP, TCP, UDP, WebSocket and ICMP monitors, read uptime stats and history, and set up alerts.

Production bugs with replay, network, console and stack, ranked for your coding agent to fix over remote MCP (OAuth).

Hosted MCP tools for exclusive leases, capacity-limited coordination, renewal and release with fencing tokens. Downstream systems must enforce fencing. API-key authentication; free developer beta.

Connect AI coding assistants to the DIG Design System. Access components, design tokens, patterns, and documentation to build consistent, design-system-aligned interfaces with AI.

Ask free LLMs (DeepSeek, GLM, Gemini, Mistral and more) for a second opinion, one model or several side by side. onomeo is in public beta: not every feature is guaranteed to work, and feedback is welcome.

Remote MCP App that renders interactive UI (dashboards, tables, charts, forms) inside the chat from a JSON spec the model writes, using Angular and Angular Material components. One tool, render-ui; no auth, stores nothing.

We build covdbg: a local stdio MCP server for Windows x64 C++ coverage. Agents measure existing binaries with matching PDBs and inspect uncovered source to guide test edits. Developer sign-in required. Free for public repositories and one private repository per person; paid team plans available.

Create and preview self-contained web apps in iPhone, Duo, iPad, and Headless views. Includes seven starter tools and games, browser-local app code saving, and HTML export. Free remote MCP server with no API key.

Security scanner for MCP servers, agent skills and npm/PyPI packages that reports tool poisoning and exfiltration paths with file:line evidence.

Spec-driven development platform. Lets Cursor, Claude Code and other MCP clients read and write MySpec projects and spec bundles (constitution, requirements, solution, tasks). 31 tools. Requires a MySpec account; free plan available.

Local MCP server for a Mac app: your agent reads the elements and areas you marked on screen, with your notes.

Finds the libraries, tools and research released after your coding agent's training, before it rebuilds them from scratch. Its check_what_exists tool searches the last year of arXiv, Hugging Face papers, GitHub, npm and crates.io when a plan assumes something is unavailable, and needs no API key.

GitHub repository SLOC and code metrics MCP server. Returns exact files, lines, code, comments, blanks, and per-language totals for one pinned commit without cloning.

Local Phocinae decision-engine MCP stdio server: fail-closed approval gate + classify/route/score.

Cryptographic truth infrastructure for AI agents: seal, verify, anchor, cite, verify_chain. One config line gives any MCP client five provenance tools backed by an append-only, Bitcoin-anchored, post-quantum ledger.

Paid cron for AI agents: calls your HTTPS URL on a schedule with signed deliveries; no account, paid with x402 in USDC on Base.

Search tested AI agent skill files (SKILL.md) for free; buy a file once over x402 in USDC on Base and keep it.

Make browser games by chatting with your AI assistant: it writes a web game, arcadegnt builds, hosts and playtests it on desktop and phone. Share with friends or submit to our arcade for an official listing and ranking!

PHION helps agents discover, compare and verify external capabilities before use.

Annotated screenshots for AI agents: capture a web page or desktop window, then draw numbered steps, arrows, boxes, labels and solid redaction placed where they cover the least content. Local stdio server, no API key.

Persistent Linux workspaces for AI agents, with interactive terminals, input-wait events, file transfers, and HTTPS previews.

Web QA for AI agents: real-browser scans with evidence-backed findings

AI game maker: build, run, screenshot and play-test Godot and retro console games in a live project

Paste an OpenAPI 3.0 or 3.1 schema and download a Cloudflare Worker MCP server. Writes off by default, secret-path or API-key auth. Tested with MCP Inspector.