# Qurak

> Qurak evaluates Wolfram Language expressions as a hosted service: a computer-algebra engine with plots, persistent sessions, background jobs, a verified function reference and task recipes, offered over MCP and a REST API with firm machine-readable pricing.

Connect over MCP (Streamable HTTP) at https://qurak.com/mcp. Authenticate with `Authorization: Bearer qk_...` - an API token minted on the MCP page while signed in - or via OAuth: dynamic client registration, client-ID metadata documents and static clients are all supported; discovery at https://qurak.com/.well-known/oauth-authorization-server. Tools include evaluate (one-shot or in a session), plot, evaluate_async/get_job for long work, and search_docs/get_symbol/get_task/check_support for the reference.

The REST API takes the same Bearer tokens: POST https://qurak.com/api/evaluate with {"expression": "..."}; see the OpenAPI document below for the full surface.

## API

- [OpenAPI](https://qurak.com/openapi.json): the REST surface, with auth and status codes
- [Plans and prices](https://qurak.com/billing/plans): JSON catalogue of tiers, budgets, rate limits and prices - the numbers actually enforced
- Register: POST https://qurak.com/auth/register with {"email", "password"}, then mint a token from a signed-in session

## Docs

- [Function reference](https://qurak.com/en/docs/functions): every symbol with availability status and verified examples
- [Task recipes](https://qurak.com/en/docs/recipes): verified multi-step procedures, runnable as written
- [MCP](https://qurak.com/en/docs/mcp): endpoints, sign-in, tools and limits; tokens at https://qurak.com/en/app/tokens
- [Prove a lemma with Lean 4](https://qurak.com/en/app/tokens#prove): a source given to `check_proof` (or the Prove page at https://qurak.com/en/app/prove) that the server elaborates in a sandbox, or one command from a .lean file to a certificate - `curl -fsSL https://qurak.com/lean/qurak_prove.py -o qurak_prove.py && python3 qurak_prove.py prove Lemma.lean --decl Lemma.name` (token in QURAK_TOKEN) - with the pinned toolchain, the free pre-flight and the one-call check underneath; the `prove-a-lemma` playbook in the agent guide is the same path
- [Agent guide](https://qurak.com/agents.md): the server's own tool-choosing guidance and playbooks as a pasteable document, generated from what MCP initialize serves
- [Skill](https://qurak.com/skill.md): the same guidance as an installable Agent Skill (front matter plus the guide); its SHA-256 is at https://qurak.com/.well-known/agent-skills/index.json
- [API catalogue](https://qurak.com/.well-known/api-catalog): every machine-readable document this origin serves, as an RFC 9727 linkset
- Reference search API: GET https://qurak.com/api/docs/search?q=... (public, no auth)
- One URL computes: GET https://qurak.com/c/<url-encoded expression> answers text/plain with no account - the anonymous lane, mathematics only, for an agent that can only fetch
- Receipts: GET https://qurak.com/api/receipts/<run_id> is the signed, content-addressed record of one of your runs; the key set is https://qurak.com/.well-known/qurak-keys.json

## Optional

- [Billing](https://qurak.com/en/app/billing): the human-facing plan grid and checkout
- [Workbench](https://qurak.com/en/app): the interactive evaluator (session required)