Developers — Undercut
Honest status: there is a read-only, unauthenticated JSON API over data Undercut already publishes, described by /openapi.json. The same data is available as read-only tools from an MCP server at https://getundercut.sh/mcp. Neither one routes or proxies anything. There is no SDK and no write endpoint. The product itself is still SKILL.md — a policy file your agent reads locally.
Every endpoint is a plain GET on https://getundercut.sh: no account, no API key, no request body. Responses are JSON with open CORS, regenerated from the repository at each deploy, and each one links to the file it came from. Anything other than GET gets a 405.
/api/policy — the routing policy (SKILL.md) as markdown, with its version./api/models — the tier-to-model mapping (models.md), structured per tier and vendor./api/results — benchmark totals and tiered-versus-baseline comparisons computed from the raw files in testing/results/, with the methodology's standing limitation and caveats attached./api/clients and /api/clients/{slug} — the coding agents with a researched install guide./api/segments — the editor and provider-setup segment router behind /setup./api/pricing — the published rate card (pricing.md)./api/teams-availability — the founder's published Teams onboarding windows./api/health — status and the deployed package version.curl https://getundercut.sh/api/modelsFull schemas and agent-oriented descriptions: getundercut.sh/openapi.json (OpenAPI 3.1). CI checks that every documented path has a handler and that every handler's real response matches its documented schema.
A read-only Model Context Protocol server at https://getundercut.sh/mcp serves the same published data as the API above, as tools. No account, no API key, no auth flow.
POST answered with one JSON response (a notification gets 202). No session ID is issued and there is no server-initiated stream, so GET and DELETE get 405.2026-07-28 (no handshake; server/discover is available) and the older initialize-based 2025-11-25, 2025-06-18, and 2025-03-26.readOnlyHint: true, destructiveHint: false, openWorldHint: false), each returning the same JSON as its REST twin as structuredContent plus a text copy: list_clients and get_client (/api/clients), get_segments, get_policy, get_models, get_benchmark_results (/api/results), get_pricing, and get_teams_availability. The largest result, get_benchmark_results, is about 40 KB of JSON.Add it to Claude Code:
claude mcp add --transport http undercut https://getundercut.sh/mcpCursor (.cursor/mcp.json in a project, or ~/.cursor/mcp.json):
{
"mcpServers": {
"undercut": { "url": "https://getundercut.sh/mcp" }
}
}VS Code (.vscode/mcp.json):
{
"servers": {
"undercut": { "type": "http", "url": "https://getundercut.sh/mcp" }
}
}Discovery: an MCP Server Card at /mcp/server-card (also at /.well-known/mcp/server-card.json), following the draft Server Card proposal, which is still experimental, and listed in /.well-known/ai-catalog.json. CI calls every tool through the real handler and checks each result against the published data and the tool's output schema, which is generated from the OpenAPI spec.
Undercut ships as a single MIT-licensed skill file, not a service:
SKILL.md convention (Claude Code, Codex, Cursor, Copilot, OpenCode).evals/, raw benchmark data in testing/results/, and this site.Install it by copying the skill into your agent's skills directory, or:
npx skills add undercutsh/firstpassThat's it — no account, no API key, no network call to us. The policy never phones home; the data API above is something you call, not something it calls.
No hosted routing API: the data API and MCP server serve published files, they don't pick models or run calls. No auth flow, no write endpoints, and no write tools. No SDK or client library. No webhook or telemetry endpoint. There is a first-party @undercut/cli package in this repo's cli/ directory, but it's a structural scaffold, not a published API: status and logout work today with no network calls, while login and sync are real control flow pointed at a backend that hasn't shipped yet, and it isn't published to npm. Full honesty write-up: getundercut.sh/cli.md.
This site's own pages register a few read-only tools through WebMCP, a proposed web standard (a W3C community group draft, in a Chrome origin trial) that lets an agent built into the browser call named functions on a page instead of scraping it. It is not an MCP server and not an API: the tools run inside the page you already have open, only in a browser that supports WebMCP, and in every other browser the script does nothing. Each tool reads a static file this site already publishes, at the moment it's called:
list_supported_clients and get_client_install_instructions — from clients.json and each agent's own install guide.get_segment_recommendation — from segments.json, with the same rules as Your setup.get_pricing — from pricing.md.get_policy_summary and get_benchmark_summary — from llms.txt, linking the methodology and raw results in testing/.None of them submits a form, starts a trial or checkout, or sends anything anywhere. The Your setup form is also marked up as a declarative WebMCP tool, since filling it in only changes what that page shows. Source: site/webmcp.js.
Undercut's paid tiers — Pro's pooled vetting ledger and hosted dashboard, and Teams' org-wide policy enforcement, shared dashboard, and seat management — are the most likely place an authenticated API or authenticated MCP tools would eventually live, since that's where server-side state (usage, ledgers, org policy) actually needs to exist. Teams is sold today through founder-run onboarding, not a self-serve API; beyond the read-only data API and MCP server above, no public interface is built yet, and nothing here should be read as a commitment to a specific interface or timeline. Pro does already make one authenticated request the free tier doesn't: a periodic policy-file sync, not a routing API and not a telemetry endpoint. Exactly what it reveals: What we can see.
The place to be when that ships is on a paid tier: start a Pro trial or Teams onboarding.
The most useful thing you can do as a developer today is read the policy file, run the eval harness yourself, or open an issue/PR against the repo:
Updated 2026-10-06. Back to Undercut · About · Privacy · Terms · Brand