ghostfolio/docs/AI-COST-ANALYSIS.md

AI Cost Analysis

Date: 2026-02-23
Project: Ghostfolio Finance Agent MVP
Scope: development, testing, and monthly production projections

Pricing Inputs

Primary model routing in MVP:

• 80% glm-5 (Z.AI)
• 20% MiniMax-M2.5 (MiniMax)

Reference pricing:

• Z.AI pricing page (glm-5): input $1.00 / 1M tokens, output $3.20 / 1M tokens
  Source: https://docs.z.ai/guides/getting-started/pricing
• MiniMax pricing page (MiniMax-M2.5): input $0.3 / 1M tokens, output $1.2 / 1M tokens
  Source: https://www.minimax.io/platform/pricing

Blended effective rates used for projections:

• Input: $0.86 / 1M (0.8 * 1.00 + 0.2 * 0.30)
• Output: $2.80 / 1M (0.8 * 3.20 + 0.2 * 1.20)

Development and Testing Costs

Measured local verification for this MVP used mocked model calls in Jest suites:

• npm run test:ai uses mocked generateText
• npm run test:mvp-eval uses mocked generateText

Direct external LLM calls from automated tests:

• API calls: 0
• Input tokens: 0
• Output tokens: 0
• Cost: $0.00

Manual smoke estimate for development sessions:

• Assumed live calls: 40
• Average tokens per call: 2400 input, 700 output
• Total estimated tokens: 96,000 input, 28,000 output
• Estimated model cost:
  96,000/1,000,000 * 0.86 + 28,000/1,000,000 * 2.80 = $0.16

Observability cost:

• LangSmith tracing integration: implemented (optional env-gated), current spend in this repository phase: $0.00

Production Cost Projections

Assumptions:

• Average AI queries per user per month: 30 (about 1/day)
• Average tokens per query: 2400 input, 700 output
• Tool call frequency: 1.5 tool calls/query (portfolio + risk/market mix)
• Verification overhead and retry buffer: 25%
• Effective cost/query before buffer: $0.004024

Monthly projection:

Users	Queries / Month	Model Cost / Month	With 25% Buffer
100	3,000	$12.07	$15.09
1,000	30,000	$120.72	$150.90
10,000	300,000	$1,207.20	$1,509.00
100,000	3,000,000	$12,072.00	$15,090.00

Sensitivity Range (Model Mix)

Same token assumptions, model-only monthly cost (without 25% buffer):

• 100 users:
  • all MiniMax-M2.5: $4.68
  • all glm-5: $13.92
• 100,000 users:
  • all MiniMax-M2.5: $4,680
  • all glm-5: $13,920

Instrumentation Plan for Exact Tracking

1. Add per-request token usage logging at provider response level.
2. Keep LangSmith traces enabled in staging for request, tool-call, and verification spans.
3. Export weekly token and cost aggregates into a versioned cost ledger.
4. Set alert thresholds for cost/query drift and high retry rates.