codex/codex-rs/codex-api

codex-api

Typed clients for Codex/OpenAI APIs built on top of the generic transport in codex-client.

• Hosts the request/response models and prompt helpers for Responses, Chat Completions, and Compact APIs.
• Owns provider configuration (base URLs, headers, query params), auth header injection, retry tuning, and stream idle settings.
• Parses SSE streams into ResponseEvent/ResponseStream, including rate-limit snapshots and API-specific error mapping.
• Serves as the wire-level layer consumed by codex-core; higher layers handle auth refresh and business logic.

Core interface

The public interface of this crate is intentionally small and uniform:

• Prompted endpoints (Chat + Responses)

  • Input: a single Prompt plus endpoint-specific options.
    • Prompt (re-exported as codex_api::Prompt) carries:
      • instructions: String – the fully-resolved system prompt for this turn.
      • input: Vec<ResponseItem> – conversation history and user/tool messages.
      • tools: Vec<serde_json::Value> – JSON tools compatible with the target API.
      • parallel_tool_calls: bool.
      • output_schema: Option<Value> – used to build text.format when present.
  • Output: a ResponseStream of ResponseEvent (both re-exported from common).

• Compaction endpoint

  • Input: CompactionInput<'a> (re-exported as codex_api::CompactionInput):
    • model: &str.
    • input: &[ResponseItem] – history to compact.
    • instructions: &str – fully-resolved compaction instructions.
  • Output: Vec<ResponseItem>.
  • CompactClient::compact_input(&CompactionInput, extra_headers) wraps the JSON encoding and retry/telemetry wiring.

All HTTP details (URLs, headers, retry/backoff policies, SSE framing) are encapsulated in codex-api and codex-client. Callers construct prompts/inputs using protocol types and work with typed streams of ResponseEvent or compacted ResponseItem values.