dsh-cost-meter

Out-of-tree dsh plugin that shows a live USD cost badge for the open conversation in the Web UI.

It is a dual-face dsh.client package:

• Host half (lib/index.js) registers a sessionCost projection on the session-projection seam. The fold tracks the current provider/model from request/header events and accumulates cost from the provider-reported usage buckets (uncached input / output / cache-read / cache-write), reusing token-meter's "replace the same (turn, step) sample instead of double-counting" rule. The view exposes the whole-session totals plus a byTurn map keyed by turn number.
• Client half (lib/client.js) registers a badge into the conversation.chat.assistant-actions slot — the action row at the end of each assistant message, alongside the turn's time/duration info. Each badge shows that turn's cost; hovering opens a tooltip with the per-bucket breakdown (input / output / cache-read / cache-write) plus the session total.

Pricing table

Pricing is USD per million tokens, keyed by provider/model:

{
  "per": 1000000,
  "currency": "USD",
  "default": { "input": 0.6525, "output": 1.9575, "cacheRead": 0.02175, "cacheWrite": 0 },
  "models": {
    "deepseek-official/deepseek-v4-pro":   { "input": 0.6525, "output": 1.9575,  "cacheRead": 0.02175, "cacheWrite": 0 },
    "deepseek-official/deepseek-v4-flash": { "input": 0.2175, "output": 0.6525,  "cacheRead": 0.00725, "cacheWrite": 0 }
  }
}

The plugin reads ~/.dsh/cost-pricing.json on boot (override the path with the DSH_COST_PRICING env var or the row's config.pricingPath). On first run it writes the default table to that path; edit it and restart dsh web to apply changes. A model without a models entry falls back to default (zero cost when no default is present).

Install

The package declares a dsh.bundle manifest, so dsh plugin add installs it and adds it to the profile's bundle layers automatically — no manual patch edit:

dsh plugin --profile web add @steven-wu/dsh-cost-meter
# restart the web profile, then refresh the page

For a local checkout during development:

dsh plugin --profile web add file:/path/to/dsh-cost-meter

Notes:

• @deepseek-ai/dsh-* are declared as peerDependencies (resolved from the harness), never as dependencies — installing them into a profile shadows the harness copy and can pull a stale dist-tag.
• The Settings "Plugins" panel is read-only (inventory + config cards); install happens only through dsh plugin --profile … add.
• Purely-cordis mounting (a cordis.patch.yml insert row) also works — the shipped cordis.patch.yml holds that row for either path.

The sessionCost projection is delivered through the same seam as tokenUsage / sessionStats, so it also appears in every projection carrier (history tail page, session/projection push frames) without extra wiring.