This PR adds an experimental `persist_extended_history` bool flag to app-server thread APIs so rollout logs can retain a richer set of EventMsgs for non-lossy Thread > Turn > ThreadItems reconstruction (i.e. on `thread/resume`). ### Motivation Today, our rollout recorder only persists a small subset (e.g. user message, reasoning, assistant message) of `EventMsg` types, dropping a good number (like command exec, file change, etc.) that are important for reconstructing full item history for `thread/resume`, `thread/read`, and `thread/fork`. Some clients want to be able to resume a thread without lossiness. This lossiness is primarily a UI thing, since what the model sees are `ResponseItem` and not `EventMsg`. ### Approach This change introduces an opt-in `persist_full_history` flag to preserve those events when you start/resume/fork a thread (defaults to `false`). This is done by adding an `EventPersistenceMode` to the rollout recorder: - `Limited` (existing behavior, default) - `Extended` (new opt-in behavior) In `Extended` mode, persist additional `EventMsg` variants needed for non-lossy app-server `ThreadItem` reconstruction. We now store the following ThreadItems that we didn't before: - web search - command execution - patch/file changes - MCP tool calls - image view calls - collab tool outcomes - context compaction - review mode enter/exit For **command executions** in particular, we truncate the output using the existing `truncate_text` from core to store an upper bound of 10,000 bytes, which is also the default value for truncating tool outputs shown to the model. This keeps the size of the rollout file and command execution items returned over the wire reasonable. And we also persist `EventMsg::Error` which we can now map back to the Turn's status and populates the Turn's error metadata. #### Updates to EventMsgs To truly make `thread/resume` non-lossy, we also needed to persist the `status` on `EventMsg::CommandExecutionEndEvent` and `EventMsg::PatchApplyEndEvent`. Previously it was not obvious whether a command failed or was declined (similar for apply_patch). These EventMsgs were never persisted before so I made it a required field.
codex-core
This crate implements the business logic for Codex. It is designed to be used by the various Codex UIs written in Rust.
Dependencies
Note that codex-core makes some assumptions about certain helper utilities being available in the environment. Currently, this support matrix is:
macOS
Expects /usr/bin/sandbox-exec to be present.
When using the workspace-write sandbox policy, the Seatbelt profile allows
writes under the configured writable roots while keeping .git (directory or
pointer file), the resolved gitdir: target, and .codex read-only.
Linux
Expects the binary containing codex-core to run the equivalent of codex sandbox linux (legacy alias: codex debug landlock) when arg0 is codex-linux-sandbox. See the codex-arg0 crate for details.
All Platforms
Expects the binary containing codex-core to simulate the virtual apply_patch CLI when arg1 is --codex-run-as-apply-patch. See the codex-arg0 crate for details.