ai-coding-agents-provider-runtime

# AI Coding Agents Provider Runtime Use this skill to design or review the model-provider layer inside a coding-agent runtime: provider abstraction, streaming semantics, tool-call protocol normalization, context-window strategy, retries, and fallback routing. This skill owns the model-facing runtime surface for coding agents. It is the main missing layer when trying to generalize Claude Code-derived patterns toward Codex-class portability. ## ASCII Flow ```text agent turn | v provider selection capability needs + model policy + cost/latency + context window | v request normalization messages + tools + structured outputs + cache hints + metadata | v provider stream tokens + tool calls + errors + usage events | v runtime event model normalized deltas + retries/fallbacks + final response ``` ## Quick Reference | Question | Read | Outcome | |----------|------|---------| | How should providers and streaming semantics be normalized? | [`references/provider-abstraction-and-stream-normalization.md`](references/provider-abstraction-and-stream-normalization.md) | Stable provider interface, streaming event model, and tool-call normalization | | How should retries, context windows, and fallback routing work? | [`references/context-window-retries-and-fallback-routing.md`](references/context-window-retries-and-fallback-routing.md) | Provider selection, truncation rules, retry classes, and fallback policy | | How does OpenAI Codex check local OSS provider readi...