research-git/playbook 01
01/04
PUBLIC HISTORY · COUNTERFACTUAL PLAYBOOK

Time travel is easy.Feature travel is hard.

Four real Codex features were added, removed, and rebuilt. Replay the idea—not the old diff.

YL
AUTHOR · OPEN TO COLLABORATIONYuxiang Lin
lum.is-a.dev
Inspect source PRs
12 PRs•4 feature arcs•openai/codex
WebSocket transport
REPLAYED

Reapplied with split event loops

View evidence ↗
01CASE FILES

Four removals.
Four different kinds of return.

Each arc is reconstructed from public Codex PRs. Pick a capsule to see what disappeared, what survived, and what had to change on the way back.

CAPSULE 01 / 04

WebSocket transport

ADAPTED REPLAY6 DAYS

A multi-client transport shipped, was pulled after a suspected deadlock, then returned with the same intent and a safer concurrency model.

transportconcurrencyreliability
03
FEB 11 · 2026

Reapplied with split event loops

The transport returns with dedicated inbound and outbound tasks so full queues cannot couple the two paths.

This is the clearest capsule replay: preserve the feature contract, regenerate its implementation against the newly understood constraint, and stress-test 10+ concurrent requests.

PUBLIC RECORD
PR #11370 ↗
7053aa54
TOUCHED SURFACEapp-server/src/transport.rsapp-server/src/lib.rstests/suite/v2/connection_handling_websocket.rs
02REPLAY LAB

Same feature.
Different destination.

CAPSULE REGENERATOR
WebSocket · TODAY'S CODE
REPLAY PATH
01Recall idea
→
02Read today’s code
→
03Regenerate
WHAT THIS CAPSULE WOULD REMEMBER01 / WebSocket transport
01 · INTENT

Let multiple clients use app-server over WebSockets without leaking responses across connections.

02 · INVARIANTS

Initialization is per connection; replies return to their origin; saturated queues cannot deadlock ingress and egress.

03 · CODE SLICES

Transport parsing, connection state, inbound/outbound routing, WebSocket integration coverage.

04 · RESURRECTION GUIDE

Rebuild around independent inbound/outbound tasks, retain bounded queues, then replay the connection-isolation tests.

03THE PLAYBOOK

Git remembers
what changed.

research-git remembers why.

ABOUT THIS DEMO

These feature arcs are factual reconstructions from public Codex PRs. research-git was not used in the historical changes; this demo shows how their intent could have been captured and replayed as Feature Capsules.

Explore research-git Read the capsule spec