fire-cost

fire-cost is a command for coding agents from ThierryN/fire-flow. It costs 13 tokens per session (1,313 once invoked), scanned A, original, MIT.

A command that reports how much of the conversation context is being used, estimates session cost, and can start compaction when the session grows too large.

In plain words
What is it for?
Use it to inspect usage details, show warnings above a chosen threshold, set a cost budget, or decide when to compact context.
Why use it?
It helps prevent the agent from reaching context limits unexpectedly and losing important task information.

Command

Part of the dominion-flow plugin — 44 commands, 15 agents shipped together

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add commands/thierryn/fire-flow/fire-cost
Clone the repo
git clone --depth 1 https://github.com/ThierryN/fire-flow

Or install dominion-flow, the plugin that ships this one along with the rest of its 44 commands, 15 agents.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for fire-cost

README.md
[![agentmods](https://agentmods.dev/badge/commands/thierryn/fire-flow/fire-cost.svg)](https://agentmods.dev/commands/thierryn/fire-flow/fire-cost)
Your own site
<a href="https://agentmods.dev/commands/thierryn/fire-flow/fire-cost"><img src="https://agentmods.dev/badge/commands/thierryn/fire-flow/fire-cost.svg" alt="Measured on agentmods" height="20"></a>
Per session 13 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,313 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00013 $0.01313
Opus 5 $0.00006 $0.00656
Sonnet 5 $0.00003 $0.00263
Haiku 4.5 $0.00001 $0.00131

Measured 4d ago against content hash 4568d3de8ff8, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

fire-cost scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

commands/fire-cost.md · 183 lines

How it starts

The opening of the file, as written. The whole thing — 183 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/fire-cost — Token & Cost Intelligence

Track context usage, estimate session costs, and trigger strategic compaction before hitting limits.


Purpose

Provide real-time visibility into context window consumption and session costs. Prevents the silent failure mode where agents hit context limits mid-task with no recovery path.

Arguments

Argument Required Description
--detail No Show per-file and per-agent breakdown
--warn No Only show if above 60% context usage
--budget <amount> No Set a session cost budget (e.g., --budget $5.00)

Process

Assess the current session's context consumption:

Context Window Tiers:

Tier Usage Status Action
GREEN 0-50% Healthy No action needed
YELLOW 50-70% Caution Consider compaction soon
ORANGE 70-85% Warning Compact non-essential context NOW
RED 85-95% Critical Emergency compaction — preserve only active task
BLACK 95%+ Terminal Save state immediately, prepare handoff

Estimate context usage from:

  • Number of files read in session
  • Conversation turn count
  • Agent spawns and their responses
  • Skills loaded
  • Tool call results accumulated

Estimate session costs based on model usage:

Claude Opus 4 Pricing:

  • Input: $15 / 1M tokens
  • Output: $5 / 1M tokens

Claude Sonnet 4 Pricing:

  • Input: $3 / 1M tokens
  • Output: $15 / 1M tokens

Estimation heuristics:

  • Average file read: ~2,000 tokens
  • Average tool call result: ~500 tokens
  • Average agent spawn (round-trip): ~8,000 tokens
  • Average user message: ~200 tokens
  • Average assistant response: ~1,500 tokens

Track cumulative estimates across the session.

When context usage exceeds YELLOW tier, recommend specific compaction strategies:

Read the full file on GitHub · 183 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 4d ago First seen · 183 lines · 13 tokens per session scan A 4568d3de8ff8

Subscribe to this mod's changes

fire-cost is a command published in the GitHub repository ThierryN/fire-flow (77 stars, last pushed 21d ago), licensed MIT. It adds 13 tokens to every session and 1,313 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.