/cost -- Session & Campaign Cost Explorer

Identity

/cost gives you the full cost picture. It reads real token data from Claude Code's session files and combines it with Citadel's campaign attribution to answer: how much did this cost, where did the money go, and is it worth it?

When to Use

• /cost

  -- current session cost and burn rate

• /cost today

  -- today's total spend

• /cost week

  -- this week's spend

• /cost campaign {slug}

  -- total spend for a specific campaign

• /cost all

  -- lifetime cost summary
• When /do routes "how much", "what's the cost", "spending", "tokens", "burn rate"

Inputs

Optional arguments parsed from user message:

• today

  -- filter to today's sessions

• week

  -- filter to last 7 days

• campaign {slug}

  -- filter to a specific campaign

• all

  -- show all-time data
• No argument -- show current session

Protocol

Step 1: READ REAL DATA

Run the session-tokens.js script to get real token data:

node scripts/session-tokens.js              # current/latest session
node scripts/session-tokens.js --today      # today's sessions
node scripts/session-tokens.js --all        # all sessions (use for week/all/campaign)

Also read:

• .planning/telemetry/cost-tracker-state.json

  for live burn rate

• .planning/telemetry/session-costs.jsonl

  for campaign attribution

• scripts/pricing.json

  to show which pricing is being used

If

session-tokens.js

Step 2: RENDER BASED ON SCOPE

Current session (

/cost

=== Session Cost Report ===
Session: {sessionId (first 8 chars)}
Started: {relative time} ({absolute time})
Duration: {minutes} min

Tokens:
  Input:          {N} tokens
  Output:         {N} tokens
  Cache creation: {N} tokens
  Cache read:     {N} tokens
  Total:          {N} tokens

Cost: ${total}
Burn rate: ${rate}/min
Messages: {N} ({N} main + {N} across {N} subagents)

Model breakdown:
  claude-opus-4-6:         {N} messages (${cost}, {pct}% of spend)
  claude-haiku-4-5:        {N} messages (${cost}, {pct}% of spend)

Cache efficiency: {pct}% of input tokens served from cache
  (Higher = more cost-efficient. Cache reads cost 10x less than fresh input.)

Pricing source: scripts/pricing.json (version {version})

Today / Week / All (

/cost today

/cost week

/cost all

=== Cost Report: {Today / This Week / All Time} ===

Summary:
  Sessions: {N}
  Total cost: ${total}
  Subagents spawned: {N}
  Total messages: {N}

Top 5 sessions by cost:
  ${cost}  {duration}min  {agents} agents  {msgs} msgs  {date}
  ${cost}  {duration}min  {agents} agents  {msgs} msgs  {date}
  ...

By campaign (from session-costs.jsonl):
  {slug}: ${cost} across {N} sessions
  _unattached: ${cost} across {N} sessions

Average session: ${avg_cost} | ${avg_rate}/min | {avg_duration} min

For historical charts and billing-window views: npx ccusage

Campaign (

/cost campaign {slug}

=== Campaign Cost: {slug} ===

Total: ${cost} across {N} sessions ({N} agents, {N} min)
Average session: ${avg}

Sessions:
  {date}: ${cost} ({duration} min, {agents} agents, {msgs} msgs)
  {date}: ${cost} ({duration} min, {agents} agents, {msgs} msgs)
  ...

Step 3: ADD CONTEXT

After the cost data, add one of these contextual lines based on the numbers:

• If burn rate > $2/min: "Burn rate is high. Consider whether subagent-heavy work could be restructured into smaller focused sessions."
• If cache hit rate < 50%: "Low cache hit rate. Long conversations with many tool results tend to have lower cache efficiency."
• If no real data available: "Cost data is estimated. Real token data becomes available when sessions complete and Claude Code writes session JSONL files."
• Otherwise: no extra context needed.

Step 4: FRINGE CASES

If scripts/session-tokens.js does not exist: Fall back to session-costs.jsonl data. Show estimated costs with "(est)" marker.

If no session data exists:

No session data found. Cost tracking requires Claude Code session files
at ~/.claude/projects/. These are created automatically by Claude Code.

If pricing.json is missing or unreadable: Use hardcoded pricing in session-tokens.js. Note: "Using built-in pricing (pricing.json not found)."

If user asks about Pro/Max subscription costs:

Note: Pro/Max subscribers pay a flat monthly fee, not per-token.
The token counts shown here represent your usage volume, not billing.
For rate limit awareness, token throughput matters more than dollar cost.

Quality Gates

• Always show real data when available, estimated when not
• Always label data source: (real) vs (est)
• Never claim specific dollar savings from Citadel -- show raw hook facts instead
• Suggest ccusage for features we don't replicate (charts, billing windows)
• Round costs to 2 decimal places, tokens to nearest K/M
• Total output must fit on one screen for current-session view

Exit Protocol

/cost does not produce a HANDOFF block. It is a read-only cost exploration tool. After displaying the report, wait for the next user command.