I exhausted my Plus weekly Codex allowance while developing a real software project. Rather than immediately upgrading to Pro, I decided to run a small experiment.
I bought exactly $10 / 250 Codex credits with auto-reload OFF and continued developing normally.
This wasn't a synthetic benchmark or a collection of toy prompts. I'm building an actual software project, so my Codex workload includes repository analysis, implementation, tests, documentation, verification and commits.
I noticed that my displayed credit balance seemed to continue falling after Codex had finished working.
So I stopped sending it work and started recording the balance.
After previous activity stopped changing the displayed balance, it was stable at:
$3.48 / 87 credits
I then gave Codex one bounded, completely offline development phase.
To be precise, “one phase” does NOT mean one model call. The agent was free to perform the normal internal work necessary to complete the assignment.
During that phase it modified 8 files, added 43 tests, ran the complete 791-test suite plus verification/audits, updated documentation, committed the work, and then stopped.
Immediately after Codex finished:
$3.48 → $2.64
That made the phase appear to have consumed:
21 credits / $0.84
I then sent Codex nothing else.
Later:
$2.64 → $2.40
Still no Codex interaction.
Later again:
$2.40 → $2.08
Still no Codex interaction.
At that point, the same development phase that appeared to have consumed 21 credits when Codex stopped had posted at least:
35 credits / $1.40
That's 67% more posted usage than was visible when the agent finished.
I'm NOT claiming Codex charges for idle time.
I want to emphasize this because I don't want the observation confused with the conclusion.
The most reasonable explanation to me is delayed usage accounting/settlement for computation Codex had already performed.
If that's what's happening, I don't have a problem with the delayed accounting itself.
I have a problem with the UI not showing me that usage is still pending.
If the dashboard says:
Current balance: $2.64
while substantial already-incurred usage hasn't posted yet, how much do I actually have available?
$2.64?
$2.00?
$1.50?
I can't tell.
For a metered product, I'd really like the dashboard to expose something along the lines of:
Purchased credits: 250
Posted usage: X
Pending/committed usage: Y
Actually available: Z
Or, at minimum, clearly indicate:
“Usage reporting is delayed and additional consumption may still be pending.”
I don't object to expensive compute being expensive.
I just want the fuel gauge to tell me how much fuel I actually have left.
The other thing this $10 experiment taught me
Pay-as-you-go credits don't seem particularly economical for sustained agentic software development.
They're useful as emergency fuel after exhausting an included allowance. But for an intensive multi-day development project, watching a dollar-denominated balance drain task-by-task... without knowing how much consumption is still pending... makes it extremely difficult to judge the economics in real time.
Ironically, this experiment is making the larger 5x / 20x subscription allowances look substantially more attractive to me for concentrated development periods.
I'd also love to see some limited rollover of unused paid-plan usage. Development is bursty. Some weeks I may barely touch an agent; during a project I might use it intensively for several days. Even allowing 2-3 months of unused allowance to accumulate would be enormously useful.
But that's secondary to the reason I'm posting.
I'd like other credit users to try this.
If you've purchased Codex credits:
- Stop using Codex.
- Wait until your displayed balance appears stable.
- Record it.
- Run a normal, substantial Codex task.
- Record the balance when Codex finishes.
- Don't send Codex anything else.
- Check the balance periodically for the next 30-60 minutes.
Does your balance continue declining after Codex has stopped?
I'd especially like measurements from Plus, Pro 5x and Pro 20x users.
If enough people reproduce this, we may be able to determine whether this is normal delayed accounting, approximately how long the settlement tail lasts, and how large it can be.
I'll update this post if my $2.08 balance changes again without another Codex interaction.