Repo Atlas

From ruins to neon.

openai/codex is reconstructed as 9 major landmarks, moving from buried foundations to the current neon skyline. Minor commits are intentionally filtered out so the map tells the architectural story, not the noise.

Civilization map

Minor commits disappear. Turning points become landmarks.

The route begins in sand and ends in light. Each landmark is backed by a commit hash, score, files, and reasons.

Repository evolution atlasAn ancient desert-to-neon-city map of major commits for openai/codex.01Watchtower02Watchtower03Watchtower04Release Gate05Watchtower06Ironworks07Watchtower08Foundation Stone09Neon Citadel
Major commits only

Every landmark explains why it survived the filter.

Neon Citadel

Watchtower

Initial commit

59a180d2025-04-16100/100 impact
many files changedlarge file deltadependency changecore directory touchedarchitecture keywordtest infrastructure changehigh churn
  • .github/demo.gif
  • .github/workflows/ci.yml
  • .github/workflows/dco.yml
  • .gitignore
  • .prettierignore
Broken Columns

Watchtower

feat: expose provider capability bounds to app server clients (#20049)

8c47e362026-04-2955/100 impact
many files changedcore directory touchedtest infrastructure change
  • codex-rs/app-server-protocol/schema/json/ClientRequest.json
  • codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.schemas.json
  • codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.v2.schemas.json
  • codex-rs/app-server-protocol/schema/json/v2/ModelProviderCapabilitiesReadParams.json
  • codex-rs/app-server-protocol/schema/json/v2/ModelProviderCapabilitiesReadResponse.json
Broken Columns

Watchtower

Fix migrated hook path rewriting (#20144)

d92c9092026-04-2950/100 impact
large file deltacore directory touchedtest infrastructure change
  • codex-rs/app-server/src/config/external_agent_config.rs
  • codex-rs/app-server/src/config/external_agent_config_tests.rs
  • codex-rs/external-agent-migration/src/lib.rs
Genesis Dunes

Release Gate

Make multi-agent v2 ignore agents.max_depth (#20180)

70ac0f12026-04-2945/100 impact
core directory touchedrelease keywordtest infrastructure change
  • codex-rs/core/src/agent/control.rs
  • codex-rs/core/src/session/mod.rs
  • codex-rs/core/src/tools/handlers/multi_agents_tests.rs
  • codex-rs/core/src/tools/handlers/multi_agents_v2.rs
  • codex-rs/core/src/tools/handlers/multi_agents_v2/spawn.rs
Ironworks District

Watchtower

TUI: Remove core protocol dependency [1/7] (#20172)

1c420a92026-04-2965/100 impact
large file deltacore directory touchedarchitecture keywordtest infrastructure change
  • codex-rs/tui/src/chatwidget.rs
  • codex-rs/tui/src/chatwidget/mcp_startup.rs
  • codex-rs/tui/src/chatwidget/tests.rs
  • codex-rs/tui/src/chatwidget/tests/mcp_startup.rs
Temple of Systems

Ironworks

Add agent graph store interface (#19229)

78219152026-04-2985/100 impact
many files changedlarge file deltadependency changecore directory touched
  • codex-rs/Cargo.lock
  • codex-rs/Cargo.toml
  • codex-rs/agent-graph-store/BUILD.bazel
  • codex-rs/agent-graph-store/Cargo.toml
  • codex-rs/agent-graph-store/src/error.rs
Temple of Systems

Watchtower

Add hooks/list app-server RPC (#19778)

87742292026-04-29100/100 impact
many files changedlarge file deltadependency changecore directory touchedtest infrastructure changehigh churn
  • codex-rs/Cargo.lock
  • codex-rs/app-server-protocol/schema/json/ClientRequest.json
  • codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.schemas.json
  • codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.v2.schemas.json
  • codex-rs/app-server-protocol/schema/json/v2/HooksListParams.json
Genesis Dunes

Foundation Stone

[plugins] Allow MSFT curated plugins in tool_suggest (#20304)

ebe602d2026-04-3040/100 impact
core directory touchedtest infrastructure changefirst commit
  • codex-rs/core-plugins/src/lib.rs
  • codex-rs/core/src/plugins/discoverable.rs
  • codex-rs/core/src/plugins/discoverable_tests.rs
Neon Citadel

Neon Citadel

realtime: rename provider session ids (#20361)

8a97f3c2026-04-3065/100 impact
many files changedcore directory touchedtest infrastructure changelatest milestone
  • codex-rs/app-server-protocol/schema/json/ServerNotification.json
  • codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.schemas.json
  • codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.v2.schemas.json
  • codex-rs/app-server-protocol/schema/json/v2/ThreadRealtimeStartedNotification.json
  • codex-rs/app-server-protocol/schema/typescript/v2/ThreadRealtimeStartedNotification.ts