Hexum FAQ

Hexum is an MCP server for Cursor, Claude Code, and other coding agents. It sits between the agent and the model: hexum_shrink sends this turn instead of the repository, hexum_check fails the turn when architecture.hexum is broken, and you keep your editor. On MBPP, context dropped about 85% with the same tests passing.

No. Hexum is a hosted MCP server. You keep Cursor, Claude Code, Antigravity, Codex, or Grok. Hexum is not an IDE and not a model.

The agent calls hexum_shrink before it reads widely. The model is sent this turn, not the repository. On MBPP, measured context dropped about 85% with the same tests passing. Example turn: 18.2k → 3.1k tokens, 41 files → 6. See /benchmarks and /methodology.

No. hexum_check is deterministic. It maps files to layers in architecture.hexum and reports forbidden imports. It does not call a model.

Hexum bills tokens saved: input minus what still goes to the model. Cache hits are free. No monthly cap. No seat tax. Usage early access from €0.30 per million. Teams from €0.35 per million. See /pricing.

Tokens in minus tokens out, when that is positive. Stripe is billed on tokens saved. Calls that do not save tokens still increment calls and the in/out counters.

No. Zero Data Retention is on Usage and Teams. MCP payloads are not stored. Hexum does not train on your code. Policy: /zdr.

Turn on usage billing at /app, mint a hexum_live_ key, paste the mcpServers JSON into Cursor Settings → MCP or ~/.cursor/mcp.json, then reload. Details: /cursor.

A file in the repo. Layers group files. Rules say a layer cannot use another. hexum_check reads it. Also accepted: hexum.hexum, .hexum, or the first *.hexum in the root. Guide: /architecture-hexum.

AUTH means the key is missing, invalid, or revoked. BILLING (HTTP 403) means the key is valid but usage billing is off — or, on a team, Teams billing is off. Turn billing on at /app, then retry.