neuron-tai/.scratch/alpha-hardening/issues/04-h2-tracker-authoritative-accounting.md

Status: ready-for-agent

04 — H2: Tracker-authoritative token and work-unit accounting

What to build

Stop trusting node-reported usage for billing. The tracker already proxies responses — count tokens from the proxied stream/body and compute work units from the route it constructed, not node declarations.

Code refs:

• packages/tracker/meshnet_tracker/server.py — node_work from route construction (~1776–1782, ~1781–1782)
• packages/tracker/meshnet_tracker/server.py — streaming token/chunk billing (~1890–1921)
• packages/tracker/meshnet_tracker/server.py — non-streaming _usage_total_tokens (~1938–1943)
• packages/tracker/meshnet_tracker/billing.py — charge_request node_work split (~104–151)

Accounting fraud = inflating tokens or shard span. Per ADR-0018 §5.

Test-first

1. Red: mock upstream returns inflated usage.total_tokens in body but tracker bills that value — test expects tracker-measured count.
2. Red: node registers false shard_end; billing uses tracker route span, not registration field alone.
3. Green: authoritative counters; ignore node-reported work units on charge path.

Acceptance criteria

• Token count for billing derived from tracker-parsed proxy response — prefer tracker-measured stream chunk count; when upstream usage.total_tokens is present, use the minimum of tracker count and node-reported value (cap inflated node usage)
• Work units = tracker-computed layer span per hop at route build time (~1781–1782)
• Nodes cannot increase payout by lying about shard range mid-request
• Integration test: malicious node metadata does not inflate charge_request shares

ADR links

• ADR-0018 §5

Blocked by

• 02-a2-unified-auth-boundary.md