opencode

Paired examples throughout

Good and bad pairs

Destructuring, variable count, control flow and schema definitions each get a two-block comparison. The rule is stated in one line and then shown twice, marked good and bad.

A rule against extracting helpers

Behavioral framing

Logic stays in one function unless it is reused, hides a genuinely complex boundary, or has a name that improves the caller. The same instruction appears twice in the file, once in the general principles and once under complex logic.

Dependency direction in one sentence

A single line fixes the allowed direction across six packages, including which layers client runtime code may never reach. It can be checked at an import without opening a config file.

A four-line branch naming convention

At most three words, hyphenated, no slashes, no type prefixes, with three examples given.

Runtime invariants written as prose

The session core section states properties the type system does not hold: durable admission stays separate from model execution, one provider stream call per turn, no bridging through the legacy loop. They are written as standing constraints rather than as style.

Environment facts that prevent dead ends

The default branch is dev, a local main ref may not exist, and tests cannot run from the repository root because of a named guard. Three lines, each covering a state an agent would otherwise have to discover.