DeepSeek V4 is time-of-day priced: peak calls under-reported 2x (pricing.ts pins off-peak)

[zarguell]

DeepSeek V4 peak/off-peak pricing not modeled — peak calls under-reported 2x

Provider version: 0.6.4
Models affected: deepseek/deepseek-v4-pro, deepseek/deepseek-v4-flash,
deepseek/deepseek-v4-flash-vision-exp (deepseek/deepseek-v4-flash-fast is
fixed-rate and unaffected)

Bug

DeepSeek V4 charges by time of day. Per
commandcode.ai/docs/resources/pricing-limits:

• Off-peak (17h/day): the list rates currently in src/pricing.ts.
• Peak = 2x, Mon-Fri 01:00-04:00 and 06:00-10:00 UTC.
• Weekends are entirely off-peak, regardless of hour.

src/pricing.ts hardcodes the off-peak numbers (its own comment says so) and
calculateCommandCodeCost has no access to the request timestamp, so every
peak call is billed at half its real cost in local usage.cost.

model	off-peak in/out (cached)	peak in/out (cached)
deepseek/deepseek-v4-pro	$0.66 / $1.98 / $0.022	$1.32 / $3.96 / $0.044
deepseek/deepseek-v4-flash	$0.22 / $0.66 / $0.007	$0.44 / $1.32 / $0.014
deepseek/deepseek-v4-flash-vision-exp	$0.22 / $0.66 / $0.007	$0.44 / $1.32 / $0.014

(cache-read peak derived as the same 2x ratio; input/output are documented.)

Evidence

Across 99 consecutive deepseek/deepseek-v4-flash calls recorded in
~/.pi/agent/usage.jsonl, every one landed inside a peak window
(03:13-03:24 UTC on a Thursday) and every recorded usage.cost matched the
off-peak rate to within 1e-9. Repricing with the peak multiplier gives
exactly 2.00x ($0.1495 provider-reported -> $0.2991), which is what the
usage page bills.

Suggested fix

Make the rate lookup time-aware for the DeepSeek V4 family, e.g. extend
CommandCodeModelCost with optional peak windows (or a rateFor(model, at)
helper in pricing.ts) and call it from calculateCommandCodeCost using
Date.now(). The existing tiers mechanism is context-length based, so it
does not cover this.

A cheaper stop-gap: document that DeepSeek V4 local cost is off-peak-only, but
that still silently under-reports 7 hours a day.

[ThomasByr]

It is already documented: https://github.com/patlux/pi-commandcode-provider#pricing-display