Build Package Configuration System

[Kinflou]

Build Package Configuration System

Updated 2026-08-30 to match what shipped. The config system was rebuilt on
the rust-sitter parser (#11): the package manifest is config.idp (the
congregation format, an .idp file), parsed and interpreted into frozen
units and wired into CAS (#4). comline.toml is no longer the manifest —
that name is now the consumer-side code-generation config, a separate concern
with its own design doc
(docs/.../planning/code-generation/output-configuration.md). The remaining
open scope of this issue is cross-package dependency resolution.

Priority

P1 (High) - Enables multi-schema projects

Labels

• core
• package
• configuration
• P1

Description

Implement the package configuration system that allows multi-schema projects with
dependencies. This covers the config.idp (congregation) manifest — metadata,
code_generation capability declaration, publish_registries, and a
dependencies block — and resolving schema imports across packages.

Current State

Location: core/src/package/config/

• ✅ Manifest format: config.idp / congregation (rust-sitter grammar in
  package/config/idl/, interpreter in package/config/ir/).
• ✅ Parsed → Vec<FrozenUnit> (Namespace, SpecificationVersion,
  Dependency, CodeGeneration, PublishRegistry).
• ✅ Build pipeline: compile_package() (validate only) and build() (freeze
  into CAS, Implement Content Addressable Storage (CAS) System #4); auto-versioning via the diff engine (Implement Schema Diffing & Auto-Versioning #7).
• ❌ Dependencies: a dependencies = { name = { version, uri, hash } } block
  parses, but nothing is fetched, pinned, resolved or stored. The frozen
  Dependency struct currently keeps only author / project / version
  (drops uri / hash). No dependency graph, no circular-dependency detection.
• ❌ The frozen config is not written into a CAS commit (only frozen schemas
  are) — a reproducibility gap noted in the codegen output-config doc.

Acceptance Criteria

• Manifest format (config.idp / congregation) defined
• Manifest parser implemented (rust-sitter)
• Package build pipeline functional (compile_package / build)
• Integration with CAS system (Implement Content Addressable Storage (CAS) System #4)
• Manifest format documented
• Schema dependency resolution working
• Circular dependency detection
• Frozen config committed into CAS (reproducibility)
• Example multi-package project works end-to-end

Tasks

• Decide dependency source(s) — local path, registry uri, git — and the
  integrity model (the hash = "blake3:…" field is already in the grammar).
• Keep uri / hash on the frozen Dependency unit.
• Create package resolution algorithm (topological sort) + dependency graph
  builder.
• Circular dependency detection.
• Fetch + cache dependency packages; load their frozen schemas via CAS.
• Commit the frozen config into each version's CAS tree.
• Multi-package test cases.
• Document the config.idp manifest.

Example config.idp

congregation my_api
specification_version = 1

code_generation = {
    languages = {
        rust#1.70.0 = { package_versions = [all] }
    }
}

publish_registries = {
    mainstream = std::publish::MAINSTREAM_REGISTRY
}

dependencies = {
    stdlib = { version = "1.0.0", uri = "comline://registry.comline.io/stdlib", hash = "blake3:…" }
}

Consumer-side codegen output (comline.toml [generate]) is not part of the
manifest — see the code-generation output-configuration doc.

Dependencies

• Implement Content Addressable Storage (CAS) System #4 (CAS) — done, for frozen schema/commit storage.

Blocks

None.

[Kinflou]

⚠️ Blocked by: #4 (CAS Implementation) - package system requires CAS for content storage

[Kinflou]

Body updated to match the shipped config system (rust-sitter config.idp / congregation manifest + CAS integration). comline.toml is reassigned to consumer-side codegen output config — see docs/.../planning/code-generation/output-configuration.md. Remaining scope here is cross-package dependency resolution + committing the frozen config into CAS.