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Architecture Decision Records

This directory is the permanent, numbered record of every design decision made in this repo — see .agents/skills/engineering-workflow/references/design-decisions.md for the full process of when and how to write one. This file is just the mechanics: numbering, status, and the index.

Numbering and immutability

  • Files are NNNN-kebab-case-title.md, zero-padded to 4 digits, sequential (0001-..., 0002-..., ...). 0000-adr-template.md is the template, not a real decision — the first real ADR is 0001.
  • An ADR is immutable once its status leaves Proposed. Don't edit an Accepted ADR's Decision/Context/Considered Options to reflect a change of mind later — write a new ADR that changes Status to Superseded by ADR-XXXX on the old one and references it from the new one's Context or Links section. The old ADR stays exactly as it was when accepted; that's the point of it being a record, not a living doc.
  • Copy 0000-adr-template.md for every new ADR rather than writing one from a blank file, so the section shape stays consistent across every decision in this repo.

Status lifecycle

Proposed → Accepted → (Deprecated | Superseded by ADR-XXXX)

  • Proposed: still being discussed — the deep-dive brainstorm phase described in design-decisions.md produces a Proposed ADR before anything gets built against it.
  • Accepted: the decision this repo is actually operating under. Code should match an Accepted ADR; if it doesn't, that's drift — fix the code or supersede the ADR, the same "code and docs disagree" rule that governs the rest of this repo's documentation.
  • Deprecated: no longer the guidance, but nothing formally replaced it (rare — most decisions that stop applying get superseded by whatever replaced them instead).
  • Superseded by ADR-XXXX: a later ADR explicitly replaced this one. Follow the chain forward to the current answer rather than trusting a superseded ADR's Decision section.

How this relates to other docs

  • docs/*.md (architecture, public-api, mvp, manifesto, design-principles) describe current or intended state — what the system does or is meant to do. When a topic doc describes a decision, it should link to the ADR that made it rather than re-deriving the rationale inline. Several of these docs predate this ADR system and still carry open questions or decisions inline (the "Open Architectural Decisions"/"Open Decisions Before Implementation" lists) — resolving one of those into an ADR should also update the doc to link back here rather than leave the answer duplicated in both places.
  • docs/research/*.md, if this repo ever needs one for a longer external-reference write-up, should capture what was looked at and why, with a ## Decisions section pointing at the ADR(s) the research fed into — the research doc itself is never the system of record for what was decided.
  • README.md stays the vision/intent document; an ADR that changes product-level direction gets referenced from README.md, not duplicated into it.

Index

ADR Title Status
0001 Source Generation First Accepted
0002 Constructor Selection Algorithm Accepted
0003 Generator Package Distribution Accepted
0004 Composition Plan Discovery and Dispatch Accepted
0005 Source Generator Implementation Conventions Accepted
0006 Required Members and Nullability Metadata Accepted
0007 Composition Request and Provider Pipeline Superseded by ADR-0010
0008 Composition Scope, Shared Values, and Recursion Detection Superseded by ADR-0011
0009 Deterministic Seed and Forkable Random Source Superseded by ADR-0012
0010 Composition Request, Provider Pipeline, Failure Semantics, and Diagnostics Tracing Accepted
0011 Composition Scope, Shared Values, and Recursion Detection Accepted
0012 Composition Path Identity, Deterministic Random Forking, and CreateMany Seed Derivation Accepted
0013 Collection Generation Semantics Accepted
0014 Generator-Emitted Collection Plans Replace the Reflection-Based Dispatch Bridge Accepted
0015 Provider Identity Deferred in ProviderAttempt Superseded by ADR-0016
0016 Provider Identity Restored in ProviderAttempt Accepted
0017 Immutable Composer Configuration and Builder Model Accepted
0018 Composition Profiles Accepted
0019 Registrations and Service Provider Injection Accepted
0020 Composition Configuration Rules Accepted
0021 Row Composition Entry Point for Test-Framework Integrations Accepted
0022 Compono.Xunit Package Design Accepted
0023 Rename Compono.Xunit to Compono.XunitV3 Accepted
0024 Public Provider Extensibility Model Accepted
0025 Compono.NSubstitute Package Design Accepted
0026 Deterministic Seed Derivation for Providers and Registration Factories Accepted
0027 Compono.Bogus Package Design Accepted
0028 Configurable Bogus Member-Name Conventions Accepted
0029 Milestone 7 Dogfooding Strategy and Capability-Gap Decision Framework Accepted
0030 Compono Documentation Architecture Accepted
0031 Public Preview Release and Versioning Policy Accepted
0032 API Reference Documentation Toolchain Accepted
0033 Public Preview Samples Strategy Accepted
0034 Benchmark Suite Strategy and Redesign Accepted
0035 Compono Agent Skill Pack Accepted
0036 Call-Site Values Influencing Nested Composition Accepted
0037 netstandard2.1 Compatibility Floor Superseded by ADR-0038
0038 net8.0/net9.0 Explicit Multi-Target Accepted
0039 Future Extension Package Admission Gate and Release Sequence Accepted
0040 Compono.TUnit Package Design Accepted
0041 AOT-Safe Row-Binding Dispatch Accepted
0042 Compono-Owned Source-Generated Test Doubles Accepted
0043 Compono-Generated Test Doubles: Design Accepted
0044 Compono.TestDoubles v2: Overloaded Members, Generic Methods, Minimal Call Verification Accepted
0045 Compono.TestDoubles: Configuration-Required Members for Non-Deterministic-Default Returns Accepted
0046 Effective Interface Contract for Inherited Static Abstract Members Accepted
0047 Compono.DependencyInjection: Configured-Resolution IServiceProvider Bridge Accepted
0048 Compono.TestDoubles: Argument Matching and Argument-Aware Call Verification Accepted
0049 Compono.TestDoubles: Per-Closed-Instantiation Configuration for Generic Methods Whose Return Type Depends on Their Own Type Parameter Accepted
0050 Compono.TestDoubles: Multi-Entry, Argument-Distinguished Response Configuration Accepted
0051 Compono.Http: Handler-Based HTTP Client Testing Package Accepted
0052 Compile-Time Composition-Discovery Boundary for Registered and Nested-Resolved Types Partially Accepted (Part B shipped; Part A Proposed)
0053 Compono.TestDoubles: Invocation-Aware Callback Responses Accepted
0054 Compono.TestDoubles: Sequential/Call-Count-Based Responses Accepted
0055 Compono.Logging: First-Class Microsoft.Extensions.Logging Testing Support Accepted
0056 CompositionBuilder.Share<T>(): Graph-Wide Sharing as a Core Composition Concept Accepted
0057 Compono.MSTest Package Design Accepted
0058 Public Generator-Facing Runtime Infrastructure Accepted
0059 Compono.NUnit Package Design Accepted
0060 Compono.TestDoubles: ReceivedCalls() Retrospective Inspection and ClearCalls() Accepted
0061 Compono.Options: First-Class .NET Configuration/Options Testing Support Accepted
0062 Compono.Http: Body and Header Request Matching Accepted
0066 Compono.XunitV3.Aot: A Separate Package for xUnit v3 Native AOT Support Accepted
0067 Compono.XunitV3.Aot: Profile-Based Composition ([Compose<TProfile>]/[Compose<TProfile, TConfig>]) Accepted
0068 Generator-Wide Per-Item Emission Failure Isolation Accepted