openai-token-monitor

A tiny, dependency-light guardrail that counts your OpenAI token usage and can stop you before you blow past a daily (UTC) token cap.

Honest framing — read this first. This is a self-metering guardrail, not a billing dashboard. It counts only the OpenAI calls you route through it (reading usage off each response), buckets them by UTC day in a local append-only JSONL ledger, and — if you set a cap — refuses the next call that would exceed it. It does not know what other keys, apps, or teammates spend. The OpenAI dashboard remains the authority for org-wide truth.

Install

pip install openai-token-monitor

Quickstart

from openai_token_monitor import MeteredOpenAI

# input_price / output_price are USD per 1M tokens (copy from platform.openai.com/pricing)
client = MeteredOpenAI(daily_cap=9_000_000, input_price=0.15, output_price=0.60)
resp = client.chat.completions.create(
    model="gpt-4o-mini",
    messages=[{"role": "user", "content": "Hello!"}],
)   # cap checked BEFORE the call; usage + your prices recorded AFTER

Then check today's usage from the terminal:

$ otm status
spend ledger: 1,234,567 / 9,000,000 tokens today (UTC) — 7,765,433 remaining (~$0.31 est.)
  gpt-4o-mini      1,100,000 tokens   (900k prompt / 200k completion)
  gpt-4o             134,567 tokens   (100k prompt / 34k completion)

Set OPENAI_API_KEY as usual — the openai SDK reads it; this package does not touch it.

The "free daily allowance" and your cap

OpenAI grants some accounts a free daily token allowance (e.g. via the data-sharing program). It is per-account and changes over time, so this tool ships with the cap disabled (0) — you get monitoring immediately and opt into enforcement when you know your own number:

• Find your allowance/limits at https://platform.openai.com/settings/organization/limits.
• Set a cap a hair under it so this tool alone can never tip you into paid usage.

export OTM_DAILY_TOKEN_CAP=9000000     # enforce; 0 (default) = monitor only

or per-client: MeteredOpenAI(daily_cap=9_000_000).

When the cap is reached, the next metered call raises DailyTokenCapReached before it fires — the in-flight call that tipped you over is still recorded; the next one is blocked.

from openai_token_monitor import DailyTokenCapReached
try:
    client.chat.completions.create(model="gpt-4o-mini", messages=[...])
except DailyTokenCapReached as e:
    print(e)   # DAILY OPENAI TOKEN CAP REACHED (…/…) — resume after 00:00 UTC or raise OTM_DAILY_TOKEN_CAP

Configuration

Env var	Default	Meaning
OTM_DAILY_TOKEN_CAP	0 (disabled)	Daily UTC token cap; 0 or negative = monitor only.
OTM_LEDGER_PATH	~/.openai-token-monitor/spend.jsonl	Where the ledger is written.
OPENAI_API_KEY	—	Read by the openai SDK (not by this package).

Kwargs on MeteredOpenAI / MeteredAsyncOpenAI override env: daily_cap=, ledger_path=, ledger=, input_price=, output_price=. All other kwargs (api_key=, base_url=, organization=, …) pass through to openai.OpenAI.

Custom pricing

Pass your own prices so the $ estimate is exact — no waiting on a package update, and it works for fine-tuned or brand-new models the built-in table has never heard of:

client = MeteredOpenAI(
    daily_cap=9_000_000,
    input_price=0.15,    # USD per 1M input (prompt) tokens
    output_price=0.60,   # USD per 1M output (completion) tokens
)

The prices you pass are written into each ledger line, so otm status (a separate process) reports real dollars for that model with no table lookup. One price pair applies to every model called through the client — use a second client for a differently-priced model, or omit the prices to let the built-in table handle known models. SpendLedger.record(model, prompt_tokens, completion_tokens, input_price=..., output_price=...) accepts the same pair for the low-level API.

Low-level ledger (explicit style)

from openai_token_monitor import SpendLedger, get_shared_ledger, estimate_cost_usd

ledger = get_shared_ledger()
ledger.record("gpt-4o-mini", prompt_tokens=123, completion_tokens=45)
ledger.check_cap(9_000_000)          # raises DailyTokenCapReached if today's total >= cap
print(ledger.today_total())          # persisted (cross-process) + this process's unflushed

MeteredAsyncOpenAI is the drop-in for openai.AsyncOpenAI() with awaitable calls.

CLI

• otm status — today's usage vs. cap, remaining, estimated $, per-model breakdown. otm status --watch [SECONDS] re-prints on an interval (default 2s) until Ctrl-C.
• otm path — print the resolved ledger file path.

(openai-token-monitor is an alias for otm.)

Limitations

• Counts only calls routed through this client (or SpendLedger.record). Not org-wide.
• Streaming: usage is recorded only if the response carries it (needs stream_options={"include_usage": True}); otherwise it is silently skipped. v1 targets non-streaming; streaming is best-effort.
• Set your prices for exact $. The built-in table (openai_token_monitor.pricing.OPENAI_PRICE_PER_MILLION) intentionally covers only a couple of verified models — pass input_price/output_price to MeteredOpenAI (or SpendLedger.record) for anything else. Models with no supplied price and no table entry are tracked in tokens with no $ (and otm status says so).

License

MIT.