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CLIIssues related to the Codex CLIIssues related to the Codex CLI
bugSomething isn't workingSomething isn't working
contextIssues related to context management (including compaction)Issues related to context management (including compaction)
Description #
What version of Codex CLI is running?
codex-cli 0.144.3
What subscription do you have?
Paid ChatGPT-authenticated Codex subscription. Exact tier is redacted for privacy because the catalog/runtime regression is not account-specific.
Which model were you using?
gpt-5.6-sol
What platform is your computer?
Linux x86_64. Exact host and kernel details are redacted because they are unrelated to server-delivered model metadata.
What terminal emulator and version are you using (if applicable)?
Codex desktop/CLI environment. Local application and project identifiers are redacted.
Codex doctor report
Not included to avoid publishing machine, account, path, repository, and runtime metadata. The relevant sanitized version, model-catalog fields, and runtime values are included below.
What issue are you seeing?
Summary #
Codex has silently reduced the usable context window for gpt-5.6-sol
again.
The previous server-delivered Codex model catalog exposed:
{
"context_window": 372000,
"max_context_window": 372000,
"effective_context_window_percent": 95
}
That produced a 353,400
-token effective runtime window:
372,000 × 95% = 353,400
The current freshly fetched catalog now exposes:
{
"context_window": 272000,
"max_context_window": 272000,
"effective_context_window_percent": 95
}
Codex therefore now reports only 258,400
effective tokens:
272,000 × 95% = 258,400
This is a further 95,000-token / 26.9% reduction from the already restricted 353.4K Codex window. It is not UI rounding. Sanitized historical runtime records repeatedly report model_context_window: 353400
before the rollout and model_context_window: 258400
afterward. No local model_context_window
or auto-compaction override is configured.
Issue #31860 already documented that the earlier 353.4K Codex cap was far below the published GPT-5.6 Sol model specification. This report covers the new and materially worse regression from 353.4K to 258.4K.
The official GPT-5.6 Sol model page still advertises:
- 1,050,000-token context window
- 922,000 maximum input
- 128,000 maximum output
Source: https://developers.openai.com/api/docs/models/gpt-5.6-sol
At the same 95% effective-window policy, the advertised model would provide approximately 997,500
usable tokens. Codex now exposes only 258,400
, or 25.9% of that comparable effective capacity.
Why this is unacceptable #
This combination is infuriating: OpenAI advertises a 1.05M flagship model, initially restricts it to 353K in Codex, and then silently cuts it again to 258K. Paying users are left with more compactions, lost working context, disrupted long-running tasks, and no advance notice or explanation.
This feels dismissive of paying users and materially undermines trust in Codex as a professional development tool. Repository-scale analysis, long-running implementation work, multi-agent coordination, large specifications, and tool-heavy sessions all depend on stable context capacity. Context size is not a cosmetic setting that can be silently reduced by another 26.9%.
The pricing situation makes this even more frustrating. The same official model page states that requests above 272K input are priced at 2×
input and 1.5×
output for the full request. Codex now caps the raw window at exactly 272K, so users cannot even choose to access the published long-context tier through Codex.
To be precise: this report concerns the Codex product limit under ChatGPT authentication. The pricing comparison refers to OpenAI's published API long-context policy; it demonstrates that long-context capacity exists and is explicitly priced, while Codex prevents access to it.
Major competing platforms already offer 1M-class context:
- Google documents Gemini models with 1M or larger context windows: https://ai.google.dev/gemini-api/docs/long-context - xAI documents a 1,000,000-token window for its flagship Grok 4.3: https://docs.x.ai/developers/models/grok-4.3 - Anthropic documents a 1M context option for Claude Sonnet 4: https://docs.anthropic.com/en/docs/about-claude/pricing
A flagship coding product limited to 258K effective context is no longer competitive, especially when its underlying OpenAI model is publicly specified at 1.05M.
What steps can reproduce the bug?
- Run Codex CLI
0.144.3
with the official OpenAI provider and ChatGPT authentication. - Select
gpt-5.6-sol
. - Ensure there is no local
model_context_window
,model_auto_compact_token_limit
, provider, or project override. - Fetch or refresh the server-delivered model catalog.
- Inspect the sanitized
gpt-5.6-sol
catalog entry. - Observe
context_window: 272000
,max_context_window: 272000
, andeffective_context_window_percent: 95
. - Start or continue a thread and inspect token-usage metadata.
- Observe
model_context_window: 258400
. - Compare with earlier sanitized GPT-5.6 Sol thread records, which report
model_context_window: 353400
.
The transition was observed on 2026-07-13. Old and new values briefly overlapped across existing and newly started threads, consistent with a phased or cached server-side catalog rollout.
What is the expected behavior?
- Codex should expose the full published 1.05M GPT-5.6 Sol context window, with a clear effective input/output reserve.
- If a product-specific cap is unavoidable, it must be prominently documented before users select the model.
- Context limits must not be silently reduced for existing or new paid-user workflows.
- Active threads should retain the context contract under which they were started.
- Users should be allowed to opt into the published long-context tier when they accept the associated usage or pricing impact.
- As an immediate stopgap, restore the previous 372K raw / 353.4K effective Codex limit while full 1.05M support is implemented.
- OpenAI should explain why the context was reduced, whether the change is temporary, which plans/surfaces are affected, and how usage accounting interacts with this cap.
Additional information
Related reports:
[Critical][Codex App] GPT-5.6 Sol is catalog-capped at 372K (353.4K effective) vs the 1.05M model spec #31860— GPT-5.6 Sol was already capped at 372K raw / 353.4K effective instead of the published 1.05M.Context window changes from 1M to 258K mid-thread #29039— a GPT-5.5 thread changed from 1M to 258K mid-thread.Reopen #19464 and support 1M context #30910— request to restore 1M context support.
Privacy note: this report intentionally excludes account identifiers, thread IDs, repository names, local paths, prompts, transcripts, and exact machine metadata. Only model metadata and aggregate context-window observations required to reproduce the regression are included.
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CLIIssues related to the Codex CLIIssues related to the Codex CLI
bugSomething isn't workingSomething isn't working
contextIssues related to context management (including compaction)Issues related to context management (including compaction)