# Architecture Decision Records

One decision per file, append-only; supersede rather than rewrite.

| ADR | Title | Status |
|-----|-------|--------|
| [0001](0001-package-layout.md) | Package layout — canonical types in leaf `llm`, root re-exports | Accepted |
| [0002](0002-canonical-message-model.md) | Canonical message/content model | Accepted |
| [0003](0003-parse-grammar.md) | Parse grammar — verbatim ids, inline alias expansion, chains | Accepted |
| [0004](0004-env-dsn-providers.md) | LLM_* env-DSN provider definitions (go-llm parity + eager load) | Accepted |
| [0005](0005-provider-capabilities.md) | Provider interface and capabilities model | Accepted |
| [0006](0006-health-and-backoff.md) | Model health tracking and backoff | Accepted |
| [0007](0007-dependency-policy.md) | Dependency policy — stdlib-first, hand-rolled REST clients | Accepted |
| [0008](0008-chain-semantics.md) | Failover-chain execution semantics | Accepted |
| [0009](0009-multimodal-strategy.md) | Multimodal strategy — normalize per target, enforce at provider | Accepted |
| [0010](0010-tools-structured-output-mapping.md) | Tools and structured output — canonical shape, native mappings | Accepted |
| [0011](0011-google-provider.md) | Google provider on the official Gen AI SDK | Accepted |
| [0012](0012-agent-loop.md) | Agent run loop | Accepted |
| [0013](0013-skill-model.md) | Skill model — additive instruction+tool bundles | Accepted |
| [0014](0014-conversion-driven-extensions.md) | Conversion-driven extensions (resolvers, typed tools, hooks, ops controls) | Accepted |