Research agent bill: $220 on Opus 5.5 vs $4.80 on DeepSeek V4.1 Flash
At list prices for 20M input, 3M output and 8,000 searches, Opus 5.5 comes to about $220 while DeepSeek V4.1 Flash off-peak with free search costs $4.80; search becomes paid on Oct 31 at 16:00 UTC.
My research agent's API bill for one month: $220 on Opus 5.5, $4.80 on DeepSeek. my old invoices look f*cking embarrassing now. DeepSeek opened its own search engine to agents on Oct 17 and priced it at $0.75 per 1,000 searches. Web search on Claude's API costs $10 per 1,000. The same month on paper, at list prices (20M tokens in, 3M out, 8,000 searches): Opus 5.5: $80 input + $60 output + $80 search = $220 DeepSeek V4.1 Flash, off-peak: $3 + $1.80 + $0 = $4.80 Three things make that number: 1. Claude Code runs on DeepSeek. You point ANTHROPIC_BASE_URL at their API and paste your key, the exact env vars are in their docs. 2. Search inside Claude Code is free until Oct 31, 16:00 UTC. That's for DeepSeek API users. After the deadline those 8,000 searches cost $6. 3. Off-peak tokens cost half. Peak is only 01-04 and 06-10 UTC on weekdays. Everything else runs at $0.60 per 1M output tokens, the whole weekend included. The cheap bill comes with a different model, so I keep Opus for the hard builds and send the research grind to DeepSeek. On a Pro or Max plan you don't pay per search at all, this math is for API bills. Search goes paid Oct 31 at 16:00 UTC. Set it up this week.
This post quotes another post: x.com/0xmfox/status/2112191988405608904