Comparison · May 18, 2026
Model Context Protocol (MCP) hosting platforms let you expose an existing API to Claude, ChatGPT, and other AI agents. This page compares the seven tools most often recommended in May 2026: Vayro, Stainless, Speakeasy / Gram, Smithery, DeployStack, Composio, and Prefect Horizon.
We’re Vayro — we built one of the seven tools below. We’ve tried to be honest about where competitors beat us, because if you pick the wrong tool you’ll come back angry and we don’t want that.
What we tested: Each platform’s published documentation, GitHub repository, pricing page, and (where possible) free-tier sign-up flow, on May 18, 2026.
What we couldn’t test: Enterprise tiers we don’t have access to (Stainless Enterprise, Speakeasy Enterprise). Pricing for those was taken from sales-call notes published by third parties. We marked these clearly in the matrix.
What we updated: Prices, free-tier limits, OAuth support, and source-format support were verified on May 18, 2026 by visiting each vendor’s pricing and docs page. We’ll refresh this every quarter.
Conflict of interest: We sell competing software. We do not get paid for placement. We do not rank ourselves first by default — see Which one wins for you below for conditional recommendations, including the cases where we’d send you to a competitor.
Rows are capabilities, columns are tools. Cells are factual, not ranked. Verified May 18, 2026.
| Capability | Vayro | Stainless | Speakeasy / Gram | Smithery | DeployStack | Composio | Prefect Horizon |
|---|---|---|---|---|---|---|---|
| Source format | OpenAPI 3.x | OpenAPI 3.x | OpenAPI 3.x | TS / Python code | OpenAPI 3.x + GitHub repo | Pre-built (1,000+ apps) | Python (FastMCP framework) |
| Hosting model | Managed | Managed + SDK | Managed (Gram) + SDK | Managed registry | Managed (deploy-from-GitHub) | Managed | Managed |
| Free tier | ✓ ($0, 5K req/mo) | ✓ (OpenAPI → MCP free) | Limited preview | Migration in flux | ✓ AGPL self-host or hosted | ✓ (limited) | Limited |
| Pricing entry point | $49 / mo (Pro) | Free OpenAPI → MCP; SDKs separate | $99–500 / mo (third-party sales notes) | In flux post-2026-03 free-tier shutdown | $10 / mo Starter, $29 / mo Pro | ~$49 / mo | Beta / contact Prefect |
| Upstream OAuth for end users | ✓ Per-user PKCE+S256 | Partial | ✓ | Limited | ✓ | ✓ | Code it yourself |
| AI-generated tool descriptions | ✓ (free overlay) | ✗ (manual) | ✗ (manual) | ✗ | ✗ | N/A (pre-built) | ✗ |
| Per-tool observability / logs | ✓ Encrypted request logs | Limited | Limited | Public registry | Audit logs | Limited | Limited |
| SOC 2 / compliance | ✗ (in progress) | ✓ | ✓ | ✗ | ✗ | ✓ | ✗ |
| SOAP / on-prem DB / non-REST | ✗ | ✗ | ✗ | ✗ | ✗ | ✗ | ✗ |
| Deploy from GitHub | ✗ | ✗ | ✗ | ✗ | ✓ (this is their wedge) | ✗ | Partial |
| Open source licence | ✗ | Partial (SDK only) | Partial (SDK only) | ✗ | ✓ AGPL | ✗ | ✓ Apache-2.0 (framework only) |
| Setup time (claimed) | ~5 min | ~15 min | ~30 min | Varies | ~10 min | <5 min | Varies |
Scroll the table horizontally on narrow screens.
The honest answer is: it depends on what you have and what you need. Here’s how we’d send people, including the cases where we’d send you somewhere other than Vayro.
Vayro wins if you have a modern REST API with an OpenAPI spec, want zero ops, want AI to write your tool descriptions, and don't need SOC 2 today.
Stainless wins if you need SOC 2 today, are happy writing tool descriptions manually, and want the OpenAPI→MCP free tier from a company about to be inside Anthropic.
Speakeasy / Gram wins if you already ship Speakeasy SDKs to your customers and want MCP added to that same pipeline.
Smithery wins if you've written your MCP server by hand in TypeScript or Python and want a registry plus discoverability.
DeployStack wins if your MCP server lives in a Git repository, you want AGPL open source, and you want hosting at $10–29 / mo instead of $49+.
Composio wins if the API you want to expose is already in their 1,000+ pre-built catalog and you don't have an OpenAPI spec.
Prefect Horizon wins if you're writing the MCP server by hand in Python using the FastMCP framework and want someone else to host it.
None of the above wins if you need SOAP, on-prem databases, or non-REST protocols — AnythingMCP is the tool for that, not any of the seven on this page.
None of the above wins if you're a solo developer who doesn't care about OAuth and just wants free — openapi-mcp-generator running on Cloudflare Workers gets you there for $0.
Model Context Protocol (MCP) is a specification published by Anthropic in late 2024 that defines how AI assistants discover and call external tools. An MCP hosting platform takes your existing API — usually described as an OpenAPI spec — and exposes it as a hosted MCP server that Claude, ChatGPT, Cursor, and other agents can connect to.
The platform handles four things you would otherwise build yourself: the MCP protocol layer (JSON-RPC over HTTP / SSE / Streamable HTTP), authentication (typically OAuth 2.1 with PKCE), per-user upstream credentials for the API being wrapped, and observability over how AI agents actually use your tools.
You can also self-host. Cloudflare Workers + a generator like openapi-mcp-generator gets you most of the way for free. Hosted platforms exist because the parts that look easy (OAuth refresh tokens, request logging, tool-description quality, multi-tenant isolation) are the parts that eat your time.
Prices verified on May 18, 2026. Where the vendor doesn’t publish a public price, we’ve noted that and cited the source.
Vayro — Free tier at $0 (5K req/mo, 1 project). Pro at $49 / mo (100K req, 5 projects). Business at $149 / mo (1M req, unlimited projects). Enterprise at $499 / mo with custom domain and SLA. Flat per-account pricing, not per-server.
Stainless — OpenAPI→MCP free tier exists; SDK generation is the paid product, pricing is gated behind sales. The Anthropic acquisition (talks reported at $300M+ in May 2026) means the free tier is durable but the roadmap is now Anthropic’s.
Speakeasy / Gram — Public pricing is opaque; third-party sales notes circulating in May 2026 put entry around $99 / mo with $500 / mo common at serious teams. Gram is the MCP-specific surface; Speakeasy core is the SDK pipeline.
Smithery — Free tier shut down in March 2026, paid pricing is currently in flux. Existing users are migrating.
DeployStack — Free tier ($0, 1 deployable server). Starter at $10 / mo (5 deployable, up to 5 team members). Pro at $29 / mo (20 deployable, up to 25 team members, on-premise satellite, audit logging). AGPL-3.0 self-host is free if you run the infrastructure yourself. Their wedge is deploy-from-GitHub, not OpenAPI.
Composio — Limited free tier, paid plans around $49 / mo. Pricing is per-app, which is the right model for their catalog approach.
Prefect Horizon — Beta pricing as of May 2026. The FastMCP framework itself is Apache-2.0 and free; Prefect Horizon (the rebranded FastMCP Cloud) is paid managed hosting for it.
Upstream OAuth is what lets an AI agent call an API as a specific end user, not as the service. If your tool needs to read someone’s Stripe data, post to their Slack, or create their Linear issues, you need this. It is the single easiest dimension to get wrong, and the failure mode is buyers switching tools mid-onboarding when they hit the OAuth wall.
Vayro implements per-user OAuth with PKCE and S256 challenges, refresh-token rotation, and encrypted token storage. Each Claude or ChatGPT user authenticates to your wrapped API individually. Claude CLI and ChatGPT Apps SDK are the two clients we test on most heavily because they’re the ones our paying users ship to.
Stainless has partial OAuth support — sufficient for the read-only wrapping case, less clear for refresh-token flows. Speakeasy supports OAuth in Gram. Smithery OAuth depends on the underlying server. DeployStack supports OAuth. Composio ships OAuth for every app in their catalog by design. Prefect Horizon — code it yourself in the FastMCP server, the framework doesn’t prescribe it.
This is the dimension most comparison pages skip and one of the biggest determinants of whether your tools actually work in practice. AI agents pick which tool to call based on the description. A weak description means the agent calls the wrong tool, calls no tool, or calls the right tool with the wrong arguments. Most OpenAPI specs have weak descriptions because they were written for humans, not models.
Vayro generates AI-written descriptions on import and lets you override any of them with a versioned overlay. The overlay is free on every tier. We do this because we’ve watched buyers spend a week hand-editing tool descriptions and conclude the platform is the problem.
Stainless, Speakeasy, Smithery, DeployStack, and Prefect Horizon all expect you to write descriptions manually — either in the OpenAPI spec or in code. Composio doesn’t need this because their catalog ships with curated descriptions per app.
You’re going to depend on these companies. It’s worth knowing who they are.
Vayro — Solo founder (Traian Mirci, that’s me). UK Ltd company. Started early 2026. Bias: I built this because hand-converting OpenAPI to MCP was tedious and tool-description quality was the silent killer.
Stainless — Series-funded, well-staffed, primary product is SDK generation. As of May 2026 in advanced acquisition talks with Anthropic at reported $300M+. If that closes, expect their MCP surface to become native to claude.ai over 6–12 months.
Speakeasy — YC-backed, primary product is SDK generation. Gram is their MCP surface. Larger team than most on this list.
Smithery — MCP registry plus hosting. Free tier shutdown March 2026 indicates they’re moving up-market. Pricing volatility risk.
DeployStack — AGPL-licensed open source with a hosted offering. Different wedge (deploy-from-GitHub) and significantly cheaper. The budget-conscious AGPL-tolerant choice.
Composio — YC S23, well-funded, primary product is the pre-built app catalog (1,000+ as of May 2026). Their model only works if your API is already in the catalog or you don’t own the API.
Prefect Horizon — Hosted by Prefect (the workflow-orchestration company). The framework (FastMCP itself) is widely used; the managed hosting offering is newer and in beta as of May 2026.
We sell Vayro, so we’re going to pick Vayro most of the time. But here are the honest cases where we’d send you elsewhere:
If you need SOC 2 in your sales cycle today, ship Stainless. The Anthropic acquisition adds platform risk, but the free OpenAPI→MCP tier is real and SOC 2 is real.
If you’re budget-constrained and your MCP server is a Git repository, DeployStack at $10 / mo (Starter) or $29 / mo (Pro) with AGPL escape-hatch is the right pick. We won’t pretend our $49 / mo is competitive for this buyer.
If you don’t own the API (you’re wrapping Stripe, Slack, GitHub for an internal tool), Composio’s catalog is faster than building it yourself on any platform on this page, ours included.
If your API is SOAP, on-prem, or non-REST, AnythingMCP is the tool. We don’t cover that case and the others on this list don’t either.
An MCP hosting platform turns your existing API (an OpenAPI spec, or in some cases a code-defined server) into a Model Context Protocol server that AI assistants like Claude and ChatGPT can call as tools. The platform handles the protocol, authentication, transport, and (on better tools) request logging and tool-description quality.
No. If open source is non-negotiable for your use case, DeployStack is AGPL-3.0 and the closest direct equivalent on hosting model. FastMCP (the framework, not Prefect Horizon) is Apache-2.0.
Not yet — we're a small team and SOC 2 is in progress, not done. If you need SOC 2 today, Stainless, Speakeasy, and Composio all carry it.
You have three options: generate one (most modern frameworks can — FastAPI, Hono, NestJS, etc.), write a code-first MCP server using the FastMCP framework, or use Composio if your API is already in their catalog.
None of the seven tools on this page covers that case well. AnythingMCP is built for SOAP, WSDL, on-prem databases, and similar legacy protocols.
The Connectors Directory is a distribution channel — it's where Claude users discover MCP servers. Vayro (and every tool on this list) is what you'd build and submit to it. They're complementary, not competing.
Because tool descriptions are one of the biggest determinants of whether AI assistants actually use your tools correctly. In our experience, LLM-written descriptions outperform hand-written ones on most APIs, and we let you override any of them with a versioned overlay. None of the other six tools on this page does this for you.
Quarterly, or whenever a vendor on the list ships a material change (free-tier shutdown, acquisition closing, pricing rewrite). Last verified: May 18, 2026.
Primary sources only — vendor pricing pages, vendor docs, vendor GitHub. No aggregators.
Free tier is 5,000 requests / month with one project. No credit card. If we’re the wrong fit for you, use the matrix above to find the right one.
Last updated May 18, 2026. Prices verified May 18, 2026. We refresh this every quarter.