GPT-6 Astra Compaction Lands in Codex

Episode 1 · GPT-6 Astra's new compaction lands in Codex: notes persist across context windows (2026-09-04, 5 posts)

OpenAI has shipped a new compaction mechanism for GPT-6 Astra in Codex, disclosed by danielmac8 on September 5. The feature is experimental and off by default, requiring manual opt-in. Once enabled, the model can save key information as "notes" that persist across context windows instead of being lost with old ones; earlier context windows (including messages and tool call records) also become retrievable, rather than everything being repeatedly compressed into a single summary. danielmac8 argues this stops the model from acting like an "amnesiac." Multiple reposts and discussions (m1, m3, m5) confirm the same information.

Confirmed

• The feature is live in Codex, experimental, off by default, and requires manual opt-in (m2/m4)
• Two core capabilities: notes persist across context windows; earlier context (including messages and tool calls) becomes retrievable (m2/m3/m4)
• The goal is to solve the problem of information being repeatedly compressed and lost once the context window fills up (m3/m5)

Why it matters

• VraserX (m5) sees this as Astra's most important yet most understated feature: it looks like plumbing work, but it's a crucial step toward letting long-running agents actually accumulate state over time
• Persistent memory across windows means long-task agents no longer "forget," a significant gain for complex multi-step workflows

• GPT-6 Astra's quiet superpower: persistent notes and searchable context across windows — VraserX · 2026-09-04
• GPT-6 Astra's Codex compaction: persistent notes and searchable past contexts — daniel_mac8 · 2026-09-05
• GPT-6 Astra ships compaction in Codex: notes persist and old context stays searchable — daniel_mac8 · 2026-09-05
• GPT-6 Astra's experimental compaction in Codex saves notes across context windows, off by default — TheMoonMidas · 2026-09-05
• Codex launches Astra: notes that persist across context windows — gabrielchua · 2026-09-05

Episode 2 · Codex Astra Adds Cross-Window Notes to Tame Context Bloat (2026-09-05, 3 posts)

OpenAI's new Codex feature Astra retains notes across context windows and offers searchable history instead of repeatedly compressing context into summaries, cutting detail loss and reportedly saving significant credits on long tasks.

• Codex's experimental context management replaces compression with notes + searchable history, slashing usage — EAccelerate_42 · 2026-09-05
• Codex Astra adds cross-context note persistence to fight context bloat in long tasks — dair_ai · 2026-09-06
• Codex launches Astra: notes persist across context windows without lossy summaries — CShorten30 · 2026-09-06