Best Ray Distributed Computing MCP MCP Server Alternatives 2026

Reference/test server with prompts, resources, and tools. Perfect for testing MCP implementations.

Completely free and open-source reference server by Anthropic. No underlying service costs.

Tools to read, search, and manipulate Git repositories. Full Git operations support.

Free and open-source by Anthropic. Works with local Git repositories — no paid service required.

Knowledge graph-based persistent memory system. Store and retrieve contextual information.

Free and open-source by Anthropic. Knowledge graph stored locally — no external service costs.

a single structured-reasoning tool that lets a model plan, revise and branch its own chain of thought instead of answering in one shot. Published by Anthropic as part of the official modelcontextprotocol/servers monorepo (89,000+ stars, actively maintained), it exposes exactly one tool — sequential_thinking — and that tool is the whole product. Each call carries a `thought` string plus bookkeeping fields: `thoughtNumber`, `totalThoughts`, and `nextThoughtNeeded`, which the model flips to false when it is done. The interesting fields are the optional ones. `isRevision` and `revisesThought` let the model go back and correct an earlier step rather than plowing ahead on a bad assumption; `branchFromThought` and `branchId` let it fork into an alternative line of reasoning and carry both forward; `needsMoreThoughts` lets it extend past its own original estimate when a problem turns out to be deeper than it looked. In practice you never call the tool by hand. You connect the server to an MCP host and ask a question that deserves more than one pass — plan a PostgreSQL 14 to 16 migration and revise if downtime exceeds five minutes, work out why a deploy only fails in production, compare three architectures and branch when an assumption breaks. You can tell it is working when the host inspector shows repeated sequential_thinking calls with a rising `thoughtNumber` rather than a single response. Install with `npx -y @modelcontextprotocol/server-sequential-thinking` — note the hyphenated package name, which differs from both the `sequentialthinking` directory in the repo and the Docker image `mcp/sequentialthinking`, a mismatch that breaks a lot of copied configs. A Docker image is published alongside the npm package, and the README carries one-click VS Code install buttons for both transports. Set `DISABLE_THOUGHT_LOGGING=true` if you do not want every thought written to the server log.

Free and open-source by Anthropic. Runs locally with no external API dependencies.

Create crafted UI components inspired by the best 21st.dev design engineers.

The MCP server is free. 21st.dev offers a free tier for UI components. Pro plans available for advanced features. See official site for current pricing.

authenticated access to the whole GitHub platform — repositories, files, branches, issues, pull requests, Actions runs, security alerts, discussions and notifications — from Claude, Cursor, VS Code, Copilot CLI and any other MCP host. There is no npm package for this server, and that trips up most people who try to install it: `@github/mcp-server` is not published to the npm registry, so any `npx` line you find for it will fail. GitHub ships it three other ways. The easiest is the hosted remote server at https://api.githubcopilot.com/mcp/, which needs no install at all — point an HTTP-transport MCP client at that URL and log in with OAuth (VS Code 1.101+, Claude Desktop, Claude Code, Cursor and Windsurf all support this). The second is the official Docker image ghcr.io/github/github-mcp-server, which is what the copy-paste command on this page runs; on github.com it now performs a browser-based OAuth login on first use and keeps the token in memory only, which is why the published Docker configs map a fixed loopback callback port (-p 127.0.0.1:8085:8085 with GITHUB_OAUTH_CALLBACK_PORT=8085) so the container can receive the callback. Prefer a token? Set GITHUB_PERSONAL_ACCESS_TOKEN instead — it takes precedence over OAuth, and the minimum useful scopes are repo, read:org and read:packages. The third is the native Go binary from the repository's releases, which needs no fixed port for the OAuth flow. GitHub Enterprise Server has no hosted option: use the local server with --gh-host or GITHUB_HOST set to your instance (include the https:// scheme — it defaults to http://, which GHES rejects). Toolsets can be narrowed with GITHUB_TOOLSETS, and an insiders channel is available at /mcp/insiders or via the X-MCP-Insiders header.

The MCP server is free and open-source. GitHub: Free tier for public repos and limited private repos. Team: $4/user/mo. Enterprise: $21/user/mo.

a first-party MCP endpoint built into the GitLab instance itself — there is no package to install, because the server ships inside GitLab and answers at https://<your-gitlab>/api/v4/mcp (gitlab.com exposes the same path, so https://gitlab.com/api/v4/mcp works for SaaS projects). It landed as an experiment in GitLab 18.3 and moved to beta in 18.6. Authentication is the part that makes it different from every community GitLab server: it uses OAuth 2.0 Dynamic Client Registration, so the first time a client connects it registers itself as an OAuth application on your instance and is issued an access token — no personal access token pasted into a config file. Administrators who do not want one OAuth application per tool can pre-create a shared application instead. Three prerequisites are what actually block most first connections: GitLab Duo must be set to Always on or On by default, beta and experimental features must be enabled, and MCP access must be switched on at the group or instance level. The tool surface covers issues and merge requests (create_issue, get_issue, create_merge_request, get_merge_request, list_merge_requests, get_merge_request_commits, get_merge_request_diffs, get_merge_request_pipelines, create_merge_request_note, get_merge_request_notes), CI/CD (manage_pipeline for list/create/delete/retry/cancel, get_pipeline_jobs, get_job_log), work items (create_workitem_note, get_workitem_notes, link_work_items, get_saved_view_work_items), search (search across the instance, search_labels, semantic_code_search), list_wiki_pages, and attach_scan_profile. HTTP is the recommended transport — claude mcp add --transport http GitLab https://gitlab.com/api/v4/mcp — and clients that only speak stdio can wrap it with npx mcp-remote <url> on Node 20+. Send the X-Gitlab-Mcp-Server-Tool-Name-Prefix header if generic names like search collide with another connected server. If your instance predates 18.3 or Duo is not available to you, the community alternative most teams land on is zereight/gitlab-mcp (1,889 stars as of 2026-08-16, npm @zereight/mcp-gitlab), which authenticates with a plain personal access token and ships 217 tools — including merge_merge_request, approve_merge_request, execute_graphql and full CI/CD variable management, none of which the built-in server exposes — behind GITLAB_PERMISSION_MODE=readonly/modify and GITLAB_TOOLSETS/GITLAB_TOOLS filtering. One further change worth noting: MCP server access moved from GitLab Premium to GitLab Free in 19.2 and became a setting of its own.

The MCP server is free. GitLab: Free tier with 5 users. Premium: $29/user/mo. Ultimate: $99/user/mo.

AWS Labs maintains a monorepo of specialized, open-source MCP servers that bring AWS best practices directly into AI-assisted development workflows, spanning infrastructure, data, AI/ML, cost management, and healthcare/life-sciences domains. Rather than one monolithic server, the project ships dozens of focused servers you install individually depending on the task: the AWS Documentation MCP Server for real-time official docs and API references, dedicated servers for Terraform/CDK/CloudFormation infrastructure-as-code, container and serverless platforms (ECS, EKS, Lambda), SQL/NoSQL databases (DynamoDB, RDS, Aurora), search and analytics (OpenSearch), messaging (SQS/SNS), and cost/billing analysis. Most servers install via uvx with a package name like awslabs.aws-documentation-mcp-server, run locally over stdio, and use standard AWS credential chains (IAM roles, profiles, or access keys) rather than exposing raw account credentials to the model. AWS also now offers a managed, remote "AWS MCP Server" (in preview) that combines full API coverage with pre-built agent SOPs, syntactically validated API calls, and complete CloudTrail audit logging for teams that want centralized governance instead of running servers locally. The Getting Started with Kiro/Cursor/VS Code/Claude Code sections in the repo provide one-click install configs for each server, making it straightforward to wire up only the AWS services a given project actually touches.

The MCP server is free and open-source. AWS services use pay-as-you-go pricing. Free tier available for many services for 12 months. Costs vary by service usage.

Cloudflare ships two different things under this name. The mcp-server-cloudflare repo provides 16 remote, domain-specific MCP servers rather than one monolith — Documentation, Workers Bindings (storage/AI/compute primitives), Workers Builds, Observability (logs/analytics), Container sandboxes, Browser Rendering (fetch pages, convert to markdown, screenshots), Logpush health, AI Gateway (prompt/response search), AI Search, Audit Logs, DNS Analytics, Digital Experience Monitoring, Cloudflare One CASB, Radar, GraphQL analytics and the Agents SDK docs server, each on its own `*.mcp.cloudflare.com/mcp` hostname. Separately, the Cloudflare API MCP server at mcp.cloudflare.com/mcp (repo: cloudflare/mcp) exposes the whole 2,500+ endpoint Cloudflare API through just two tools, `search` and `execute`, using the Code Mode pattern — model-written JavaScript runs in an isolated Dynamic Worker, costing ~1,000 tokens of context against the ~1.17M an equivalent native-tool server would need. Pick a domain server when you want a readable, curated tool list for one product area; pick the API server for breadth or for endpoints nobody wrote a tool for. All endpoints are Streamable HTTP on `/mcp` and support the MCP 2026-07-28 spec; the historical `/sse` URLs remain as aliases for the same Streamable HTTP handler but no longer serve the deprecated HTTP+SSE transport, so clients pinned to SSE must switch. Auth is OAuth on connect, or a scoped Cloudflare API token as a bearer header for CI. Clients without native remote-MCP support bridge via `npx mcp-remote https://<subdomain>.mcp.cloudflare.com/mcp`.

The MCP server is free and open-source. Cloudflare: Generous free tier for Workers, KV, R2, D1. Workers Paid: $5/mo. Pro: $20/mo. Business: $200/mo.

Exa's official MCP server connects AI assistants to a search engine purpose-built for AI, using neural embeddings to match on meaning rather than keywords so agents get clean, ready-to-use content instead of a page of blue links to re-parse. The default tool set covers web_search_exa for quick topical lookups and web_search_advanced_exa for full control over domains, date ranges, and content filters, plus specialized tools for code_search (searching real-world code and GitHub), company_research (building company profiles, competitor lists, and financials), crawling/web_fetch (pulling clean content from a specific URL), people_search and linkedin_search (public professional-profile lookups), and deep_researcher_start/check for long-running multi-step research tasks backed by Exa's Research API. The server is hosted at https://mcp.exa.ai/mcp — no local process to run — and connects via one-line setup in Cursor, VS Code, Claude Code, Claude Desktop (available as a native Connector), Codex, OpenCode, Windsurf, and Antigravity, authenticated with an EXA_API_KEY from the Exa dashboard. Tool exposure is tunable per client via a ?tools= query parameter on the endpoint URL, letting teams ship narrow, purpose-built configurations (e.g. company-research-only or LinkedIn-only agents) instead of exposing the full surface, and Exa ships ready-made Claude Skills/agent definitions for common patterns like company research and people search with built-in query-variation and token-isolation guidance.

The MCP server is free and open-source. Exa: Free tier with 1,000 searches/mo. Pro plans available for higher volume. See official pricing.