magus v0.4.3 is out. See what's new
¶ View markdown source · ✎ Suggest an edit
1 min read

Built for the expensive era

Model time is subsidized today, the way early ride-hailing was: prices are set to win adoption, not to cover cost. The pattern that follows is known, not predicted. Once adoption is won, prices rise and each token buys less; enterprise contracts already show it. magus is built for that era, not this one.

The answer is to move what a model would otherwise have to work out (the graph, declared outputs, what a change can break, which conventions hold) into deterministic, checked answers. A smaller model can then do work that today takes a frontier one. A feature that only works with a frontier model is not finished. This prevents a tool that looks capable only while someone else pays for the reasoning.

Enforced by

  • The model-tier lens: the economy tier's pass rate should rise over time.
  • The static tier table in ADR 0009: a person picks the model for a tier, and nothing routes per call.

Good

One deterministic answer replaces a model reading files to rediscover it:

magus describe file docs/MAGUS.md
magus refs decodeFile --occurrences

Bad

Read every magusfile under libs/ and tell me which targets write docs/MAGUS.md.

The model spends tokens deriving a fact the graph already holds, and the answer is a guess a cheaper model gets wrong.

See also

PrinciplesPages in this section. A record of refusalsCapabilities magus could have had and does not, or had and removed, with what decided each and where to check it. SpellsA spell is a library of tool-native ops (go-build, cargo-clippy, eslint) plus cache metadata that your magusfile composes into runnable targets. AgentsHow magus equips AI agents (the installable skills, the MAGUS.md routing index, the MCP server, and the guard hook any agent host can wire), with a setup page per host.
designprincipleagentscost
Last updated (2df714e8)
Glossary

Magusfile

The magusfile.buzz that declares a project's targets (as export funs) and binds its spells. Magusfile in full.

Target

A named operation (build, test, ...) you invoke with magus run <target>; it may compose a spell's tool-native operations and depend on other targets. Target in full.

Op

A single tool-native command a target composes (long form: operation); the middle of the work hierarchy (Spell to Op to Target). Op in full.

CI

An ordinary target you compose yourself with ctx.needs; magus does not hardcode its stages. It is the anchor magus affected ci keys off, and ci strips the rw charm. CI in full.

MAGUS.md

The committed routing index at a workspace root, regenerated from the knowledge graph: it lists every node and points at the exact query for a given question, so it is the entry point an agent reads first. MAGUS.md in full.

Agent

A model working through an agent host such as Claude Code, Codex, Cursor or OpenCode. magus treats an agent as one more caller of its CLI, MCP tools and console, held to the same checks as a person. Agent in full.

Tool

An action a model can call through its host: a name, a description, a typed input and a result. magus serves its tools over MCP, each a read of the workspace model or a run of the CLI it already has. Tool in full.

Session

An agent host's conversation, by the id the host delivers to its hooks. magus never mints one: a record with no session is unattributed, and the OS user it carries says whose account ran it. Session in full.

Conventions

This page uses none of the site's convention markers. The full set is on the conventions page.