AI Assistant — API Cost Calculator

Adjust the sliders to estimate monthly Anthropic API costs. Values pre-filled from the Tomorrow Development proposal.

📊 Client Usage (ask the client)

Emails per day HIGH 100

10300

Texts / messages per day MED 55

5200

Ad-hoc questions per day MED 20

060

Active projects HIGH 5

115

Active work hours per day HIGH 14

618

Work days per month LOW 26

2030

⚙️ Architecture (we control)

Active heartbeat interval (min) HIGH 1

1 min10 min

Overnight heartbeat interval (min) MED 5

5 min30 min

Haiku heartbeat % (rest → Opus) HIGH 100%

0% (all Opus)100% (all Haiku)

Haiku → Opus escalation rate MED 10%

0%30%

Cache hit rate (active hours) MED 95%

50%99%

Cache hit rate (overnight) MED 80%

30%99%

T2 (critical context) % of tasks HIGH 12%

0%40%

T3 (deep work) % of tasks MED 3%

0%15%

System prompt size (K tokens) LOW 20

10K40K

Subagent spawns per week MED 17

050

Batch API eligible % LOW 12%

0%30%

💰 Monthly Cost Estimate

Estimated Monthly API

$3,113

~$104/day

Heartbeats

0 calls/day

User Tasks

0 calls/day

Subagents

0 spawns/mo

Compaction

0 cycles/day

Batch Savings

-$0

50% discount on eligible

📋 Cost Breakdown

Component	Daily	Monthly