Agent skill

Cost

Deep cost exploration and transparency. An agent skill from SethGammon/Citadel.

Install Cost

skills CLI

$ npx skills add SethGammon/Citadel --skill cost -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install SethGammon/Citadel cost --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/SethGammon/Citadel.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/cost .claude/skills/cost && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "cost" agent skill from https://github.com/SethGammon/Citadel/tree/main/skills/cost into .claude/skills/cost/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cost", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/SethGammon/Citadel/tree/main/skills/cost

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add SethGammon/Citadel --skill cost -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install SethGammon/Citadel cost --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/SethGammon/Citadel.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/cost .agents/skills/cost && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "cost" agent skill from https://github.com/SethGammon/Citadel/tree/main/skills/cost into .agents/skills/cost/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cost", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add SethGammon/Citadel --skill cost -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install SethGammon/Citadel cost --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/SethGammon/Citadel.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/cost .cursor/skills/cost && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "cost" agent skill from https://github.com/SethGammon/Citadel/tree/main/skills/cost into .cursor/skills/cost/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cost", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/SethGammon/Citadel.git --path skills/cost

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add SethGammon/Citadel --skill cost -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install SethGammon/Citadel cost --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/SethGammon/Citadel.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/cost .gemini/skills/cost && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "cost" agent skill from https://github.com/SethGammon/Citadel/tree/main/skills/cost into .gemini/skills/cost/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cost", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install SethGammon/Citadel cost

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add SethGammon/Citadel --skill cost -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/SethGammon/Citadel.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/cost .github/skills/cost && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "cost" agent skill from https://github.com/SethGammon/Citadel/tree/main/skills/cost into .github/skills/cost/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cost", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add SethGammon/Citadel --skill cost -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install SethGammon/Citadel cost --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/SethGammon/Citadel.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/cost .opencode/skills/cost && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "cost" agent skill from https://github.com/SethGammon/Citadel/tree/main/skills/cost into .opencode/skills/cost/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "cost", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: cost
GitHub stars: 922
Token cost: ~1.7k tokens
SKILL.md length: 552 words
Files: 1
Skills in repo: 48
Repo updated: Oct 1, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Deep cost exploration and transparency. An agent skill from SethGammon/Citadel.

Works in 4 steps: READ REAL DATA → RENDER BASED ON SCOPE → ADD CONTEXT → …
Agent Workflows work in your project
SKILL.md covers When to Use, Inputs, Protocol and Fringe Cases, plus 3 more sections
Calls node

What it does

Cost is an agent skill from SethGammon/Citadel. Deep cost exploration and transparency. Shows real token usage, session costs, campaign spend, burn rates, and model breakdown. Reads Claude Code's native session data for exact numbers. Complements /dashboard with focused cost views.

Its SKILL.md is about 1.7k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Agent Workflows. The repository describes itself as: The operating layer for Claude Code + OpenAI Codex: persistent project memory, intent routing, safety hooks, cost telemetry, and parallel agent fleets. The licence is MIT.

When your agent uses it

Agent Workflows work in your project

Example prompts

“/cost”

Requirements

Node.js

Workflow steps

4 steps, taken from the step headings in SKILL.md.

READ REAL DATA
RENDER BASED ON SCOPE
ADD CONTEXT
FRINGE CASES

What it can do on your machine

Read from SKILL.md and the folder at commit e41ff1d. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
- node
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Cost loads about 1.7k tokens when it runs. Until then it costs about 60 tokens; SKILL.md has 552 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~60
When it runs · the whole SKILL.md, loaded when a task matches: ~1.7k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from SethGammon/Citadel at commit e41ff1d, republished under its MIT licence (© SethGammon). 552 words, ~1,652 tokens.

Download SKILL.mdSave it as .claude/skills/cost/SKILL.md (or your agent's skills folder).

name: cost
description: Deep cost exploration and transparency. Shows real token usage, session costs, campaign spend, burn rates, and model breakdown. Reads Claude Code's native session data for exact numbers. Complements /dashboard with focused cost views.
license: MIT
user-invocable: true
auto-trigger: false
trigger_keywords: cost, costs, cost breakdown, campaign cost, token usage, burn rate, model breakdown
last-updated: 2026-03-30

/cost -- Session & Campaign Cost Explorer

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:

bash

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)

Step 2: RENDER BASED ON SCOPE

Current session (/cost with no args):

=== 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.

Show full SKILL.md (253 more words)Show less

Fringe Cases

Telemetry directory missing: .planning/telemetry/ does not exist — output: "No telemetry data found. Run any skill first to generate session data, then re-run /cost."
Malformed telemetry JSON: a session-*.json file fails to parse — output: "Telemetry file is corrupted. Delete .planning/telemetry/session-*.json and re-run the skill that generated it." Skip the bad file and continue with the rest.
MCP cost API returns no data: Claude Code is not tracking this session — output: "Session cost unavailable from MCP. Check that Claude Code is running with cost tracking enabled. Showing telemetry file data only." Fall back to session-costs.jsonl.
All session files are from a different project: project paths in the files do not match the current working directory — warn: "Session files found belong to a different project. You may be in the wrong directory." List the project paths found in the session files.

Contextual Gates

Disclosure: "Reading telemetry and session data. No files modified." Reversibility: green — read-only; no files modified Trust gates:

Any: full cost report, session data, campaign attribution.

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.

Files

Just SKILL.md in skills/cost of SethGammon/Citadel.

Open the folder on GitHubat commit e41ff1d

Compare with similar skills

Cost next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Cost compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Cost this skillSethGammon/Citadel	922	—	~1.7k	Automated safety check: Pass	MIT	7 days ago
MCP Server Builderanthropics/skills	180k	64 repos	~2.3k	Automated safety check: Pass	Apache-2.0	3 days ago
Hook Development for Claude Code Pluginsanthropics/claude-plugins-official	38k	11 repos	~4.1k	Automated safety check: Notes	Apache-2.0	yesterday
Using Superpowersfarm-fe/farm	5.6k	35 repos	~1.4k	Automated safety check: Pass	MIT	17 days ago
Executing Plans Inlineobra/superpowers	296k	2 repos	~5.1k	Automated safety check: Pass	MIT	yesterday
Claude Code Agent Developmentanthropics/claude-plugins-official	38k	8 repos	~2.8k	Automated safety check: Pass	Apache-2.0	yesterday

Similar skills

MCP Server Builder
anthropics/skills
Official
Guides the design and implementation of Model Context Protocol servers in TypeScript or Python, from tool naming and error messages to evaluation.
180k GitHub starsUsed in 64 repos~2.3k tokens
Agent WorkflowsAuto-check passed
Hook Development for Claude Code Plugins
anthropics/claude-plugins-official
Official
Explains how to write Claude Code plugin hooks, both prompt-based checks and bash commands, for events such as PreToolUse, Stop and SessionStart.
38k GitHub starsUsed in 11 repos~4.1k tokens
Agent WorkflowsAuto-check: notes
Using Superpowers
farm-fe/farm
A skill your agent uses when starting any conversation - establishes how to find and use skills, requiring Skill tool invocation before ANY response including clarifying questions
5.6k GitHub starsUsed in 35 repos~1.4k tokens
Agent WorkflowsAuto-check passed
Executing Plans Inline
obra/superpowers
Has the agent carry out an implementation plan itself, task by task in the current session, keeping a ledger, proving each step with a test and ending with one whole-branch review.
296k GitHub starsUsed in 2 repos~5.1k tokens
Agent WorkflowsAuto-check passed
Claude Code Agent Development
anthropics/claude-plugins-official
Official
Explains how to write agents for Claude Code plugins: the markdown file with YAML frontmatter, trigger descriptions, model and color settings, and system prompt design.
38k GitHub starsUsed in 8 repos~2.8k tokens
Agent WorkflowsAuto-check passed
Skill Creator
Azure/azqr
Official
Create new skills, modify and improve existing skills, and measure skill performance.
795 GitHub starsUsed in 89 repos~8.2k tokens
Agent WorkflowsAuto-check passed

Questions about Cost

What does Cost do?

Deep cost exploration and transparency. An agent skill from SethGammon/Citadel. Cost is an agent skill from SethGammon/Citadel. Deep cost exploration and transparency.

When should I use Cost?

Cost fits situations like: agent Workflows work in your project.

How do I install Cost in Claude Code?

Run `npx skills add SethGammon/Citadel --skill cost -a claude-code`. Or copy the skill folder (skills/cost in SethGammon/Citadel) into .claude/skills/cost in your project. Claude Code loads it when a task matches its description.

How do I install Cost in Codex?

Run `npx skills add SethGammon/Citadel --skill cost -a codex`. Or copy the skill folder (skills/cost in SethGammon/Citadel) into .agents/skills/cost in your project. Codex loads it when a task matches its description.

Can I use Cost in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add SethGammon/Citadel --skill cost -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/cost, .gemini/skills/cost, .github/skills/cost and .opencode/skills/cost in your project.

What does Cost need to run?

Going by SKILL.md and its folder, Cost needs the command-line tools its instructions call (node). Our summary lists: Node.js.

Does Cost access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Cost safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Cost use?

Cost is published under the MIT licence (declared in SKILL.md). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Cost use?

About 1.7k tokens (SKILL.md is roughly 6.6k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Cost?

Skills that share tags, products or a category with Cost: MCP Server Builder (anthropics/skills, 180k stars), Hook Development for Claude Code Plugins (anthropics/claude-plugins-official, 38k stars), Using Superpowers (farm-fe/farm, 5.6k stars) and Executing Plans Inline (obra/superpowers, 296k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Cost?

SethGammon (a GitHub user) maintains it in SethGammon/Citadel, which has 922 GitHub stars. The repository holds 48 skills in this directory. The repository was last updated on October 1, 2026.

Source: SethGammon/Citadel on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Cost

Facts

At a glance

What it does

When your agent uses it

Example prompts

Requirements

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

/cost -- Session & Campaign Cost Explorer

When to Use

Inputs

Protocol

Step 1: READ REAL DATA

Step 2: RENDER BASED ON SCOPE

Step 3: ADD CONTEXT

Step 4: FRINGE CASES

Fringe Cases

Contextual Gates

Quality Gates

Exit Protocol

Files

Compare with similar skills

Similar skills

More from SethGammon/Citadel

Related

Questions about Cost