Architecture & the Firewall

brink is a workspace of focused crates with strict dependency rules. The central design principle is the firewall: brink-format is the only crate shared between the compiler and the runtime, so the runtime has zero knowledge of source-level concepts.

The firewall principle

The crate graph is split into two halves by brink-format:

• Compiler side — every crate that understands ink source code (syntax, IR, analysis, codegen). Internal; may change without notice.
• Runtime side — brink-runtime, which only understands compiled bytecode. It depends exclusively on brink-format.

This split has real, practical consequences:

• The runtime never links the compiler. Shipping brink-runtime does not pull in the parser, analyzer, or codegen — the embeddable binary stays small.
• brink-format defines everything that crosses the boundary — StoryData, ContainerDef, AddressDef, Opcode, Value, DefinitionId, and the rest. Source-level types (AST, HIR, symbols) never leak through it.
• Hot-reload works — because the runtime loads bytecode without the compiler present, new StoryData can be swapped in at runtime.
• Save-file portability — the runtime speaks only in DefinitionIds (stable hashes), so save state isn’t tied to a particular compilation.

The same firewall is why the LSP depends on the analyzer but not the compiler: editor features need parse-through-analysis, not codegen.

For the full crate inventory, paths, and the exact dependency rules, see Contributing › Crate Layout. For how source becomes bytecode, see The Compilation Pipeline.