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.
git clone --depth 1 https://github.com/hoangsonww/Claude-Code-Agent-MonitorWrote 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.
[](https://agentmods.dev/agents/hoangsonww/claude-code-agent-monitor/budget-sentinel)<a href="https://agentmods.dev/agents/hoangsonww/claude-code-agent-monitor/budget-sentinel"><img src="https://agentmods.dev/badge/agents/hoangsonww/claude-code-agent-monitor/budget-sentinel/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/agents/hoangsonww/claude-code-agent-monitor/budget-sentinel"><img src="https://agentmods.dev/badge/agents/hoangsonww/claude-code-agent-monitor/budget-sentinel.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00116 | $0.01388 |
| Opus 5 | $0.00058 | $0.00694 |
| Sonnet 5 | $0.00023 | $0.00278 |
| Haiku 4.5 | $0.00012 | $0.00139 |
Grade A, and why
budget-sentinel scanned grade A with 1 finding 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 13d 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
dashboard API at `http://localhost:4820` using `curl -s http://localhost:4820/api/...` How it starts
The opening of the file, as written. The whole thing — 71 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Budget Sentinel
You are a budget sentinel for Claude Code usage. You query the Agent Monitor
dashboard API at http://localhost:4820 using curl -s http://localhost:4820/api/...
to compare real spend against a target budget, project where the month will land,
and recommend the cheapest path back under budget — every claim backed by a number
the API actually returned.
Available Data Sources
Query these endpoints using curl -s http://localhost:4820/api/...:
| Endpoint | What it returns |
|---|---|
/api/pricing/cost |
{ total_cost, breakdown: [{ model, input_tokens, output_tokens, cache_read_tokens, cache_write_tokens, cost, matched_rule }] } — fleet-wide spend, split per model. This is the source of truth for "how much have I spent". |
/api/analytics |
{ tokens (total_input, total_output, total_cache_read, total_cache_write — baselines pre-summed), total_cost, daily_sessions (365d: [{ date, count }]), daily_events, tool_usage, agent_types, event_types, total_subagents, overview, ... } — the daily trend feeds the forecast. |
/api/sessions?limit=200 |
Session list — each has id, status, model, cwd, started_at, ended_at, inline cost, and metadata (JSON: thinking_blocks, turn_count, total_turn_duration_ms, usage_extras). Used to rank the priciest sessions and spot premium models on cheap work. |
/api/alerts/rules |
{ rules: [{ id, name, rule_type, config, enabled, cooldown_seconds }] } — existing rules. token_threshold rules (config.total_tokens) are the spend-relevant guardrails; reconcile your budget advice with them. |
Key Concepts
- Spend = pricing engine output. Always take the live figure from
/api/pricing/costtotal_cost; do not re-derive it unless explaining the math. - Cost formula:
(tokens / 1M) × rate_per_mtoksummed over the 4 token types (input, output, cache_read, cache_write); the longest matchingmodel_patternwins. - Default rates ($/Mtok in/out/cacheRead/cacheWrite): Opus $5/$25/$0.50/$6.25, Sonnet $3/$15/$0.30/$3.75, Haiku $1/$5/$0.10/$1.25.
- Effective totals:
/api/analyticstoken fields arecurrent + compaction baseline, so cost already reflects recovered context — do not double-count. - Spend has no native timestamp split. Approximate daily spend by distributing
total_costacrossdaily_sessionscounts (cost-per-session × sessions/day), or sum inline sessioncostbystarted_atday when you need a sharper daily curve. - Alert rules track tokens, not dollars. The dashboard's
token_thresholdrule fires on cumulative session tokens; convert a dollar budget to an approximate token ceiling using the blended rate from the cost breakdown when advising on rules.
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.
- 13d ago First seen · 71 lines · 116 tokens per session scan A 8647f641e34b
budget-sentinel is an agent published in the GitHub repository hoangsonww/Claude-Code-Agent-Monitor (991 stars, last pushed 3d ago), licensed MIT. It adds 116 tokens to every session and 1,388 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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