How Much Does an Agentic Tool-Use Loop Cost per Month?

At production volume (25,000 calls/month), the cheapest effective option is Amazon Nova Micro at $27.38/month. The most expensive frontier option, GPT-5.4 Pro, runs $29,232/month — An agent task is not one call — it is a chain of several small round-trips (plan, call a tool, read the result, decide the next step), and the per-task cost is the sum of the whole chain.

How much does agentic tool loop cost per month?

At production volume (25,000 calls/month), the cheapest effective option for agentic tool loop is Amazon Nova Micro at $27.38 per month, verbosity-adjusted rather than list price. The most expensive frontier model, GPT-5.4 Pro, runs $29,232 per month for the same workload.

Verified 2026-08-08

Cheapest ≠ best. This page ranks by effective cost only. See our graded results for this task on Best LLM For →

Token shape

Shape	many small round-trips per completed task
Input / output tokens per call	3K in / 0K out × 8 turns
Cacheable input	70%
Batch-eligible	No

"callsPerMonth" here counts completed tasks, each made of 8 model round-trips (plan → tool call → observe, repeated). Tool schemas and growing scratchpad context make most of each turn's input cacheable.

What drives this workload's cost?

The main token-volume driver here is input tokens: each call sends 3K input tokens and requests up to 0K output tokens, at 25,000 calls per month in the default volume. 70% of input is modeled as cache-eligible, so repeated prefixes can reduce the input charge. It is not marked batch-eligible because the profile assumes a synchronous response.

Volume

Side project

2,500 calls/mo

$2.74/mo cheapest

Production

25,000 calls/mo

$27.38/mo cheapest

Scale

250,000 calls/mo

$274/mo cheapest

Ranked cost — Production volume

Model	Provider	List monthly	Effective monthly	Verbosity	Rank Δ
Amazon Nova Microbudget	Amazon	$29.40	$27.38	0.76×	—
Amazon Nova Litebudget	Amazon	$50.40	$49.10	0.91×	—
GPT-5 Nanobudgetlegacy	OpenAI	$54.00	$36.49	—	—
Gemini 2.5 Flash Litebudgetlegacy	Google	$84.00	$47.29	—	▲2
GPT-6 Lunabudget	OpenAI	$90.00	$54.98	—	▲2
GPT-6 Luna Probudget	OpenAI	$90.00	$54.98	—	▲2
GPT-OSS 20Bbudget	Groq	$63.00	$97.74	2.93×	▼3
Ministral 8Bbudget	Mistral	$99.00	$98.37	0.93×	▲1
Mistral Small 3.1budget	Mistral	$126	$121	0.85×	▲4
GPT-4o Minibudgetlegacy	OpenAI	$126	$73.47	—	—
Grok-3 Minibudgetlegacy	xAI	$126	$126	—	—
GPT-OSS 120Bbudget	Groq	$126	$156	1.82×	—
Llama 4 Maverickbudgetlegacy	Groq	$156	$156	—	▲1
GPT-5.4 Nanobudgetlegacy	OpenAI	$195	$108	0.78×	▲1
Muse Spark 1.3 Contributorbudget	Meta	$72.00	$215	12.95×	▼10

Show all 76 models

Codestralbudget	Mistral	$234	$223	0.79×	—
Gemini 3.1 Flash Litebudgetlegacy	Google	$240	$137	0.87×	—
GPT-5 Minibudgetlegacy	OpenAI	$270	$182	—	▲1
GPT-OSS 120B (Cerebras)budget	Cerebras	$255	$314	2.32×	▼1
Gemini 3.5 Flash Litebudget	Google	$330	$220	—	—
Gemini 2.5 Flashbudgetlegacy	Google	$330	$220	—	—
Mistral Large 3budget	Mistral	$390	$390	—	▲1
DeepSeek V4 Flashbudget	DeepSeek	$343	$469	2.59×	▼1
GLM-5.1midlegacy	Z.ai	$492	$492	—	—
Qwen 3.8 30Bmid	Groq	$540	$540	—	—
Qwen 3.6 27Bmidlegacy	Groq	$540	$540	—	—
Qwen 3.7 Plusmid	Qwen	$600	$600	—	—
Amazon Nova Promid	Amazon	$672	$672	—	—
Gemini 3.7 Flashmid	Google	$675	$400	—	—
GPT-5.4 Minimidlegacy	OpenAI	$720	$457	—	—
Gemini 3.1 Flashmidlegacy	Google	$720	$445	—	—
Claude Haiku 4.5mid	Anthropic	$900	$689	—	▲1
o3-Minimidlegacy	OpenAI	$924	$539	—	▲1
GPT-5.6 Lunamidlegacy	OpenAI	$960	$610	—	▲1
Grok 4.3mid	xAI	$900	$962	1.41×	▼3
Muse Spark 1.3mid	Meta	$1,005	$1,005	—	—
Mistral Medium 3mid	Mistral	$1,350	$1,278	0.84×	▲5
Qwen 3.8 Maxmid	Qwen	$1,344	$1,344	—	▲1
Qwen 3.7 Maxmid	Qwen	$1,344	$1,344	—	▲1
Gemini 3.6 Flashmid	Google	$1,350	$799	—	▲1
GPT-5midlegacy	OpenAI	$1,350	$912	—	▲2
Grok-3midlegacy	xAI	$1,440	$1,440	—	▲2
Gemini 3.5 Flashmidlegacy	Google	$1,440	$889	—	▲2
Grok-4.20 Reasoningmid	xAI	$1,560	$1,560	—	▲3
Grok-4.20mid	xAI	$1,560	$1,560	—	▲3
Grok 4.6mid	xAI	$1,560	$1,560	—	▲3
Grok 4.5mid	xAI	$1,560	$1,560	—	▲3
DeepSeek V4 Promid	DeepSeek	$1,030	$1,576	3.30×	▼11
Gemini 3.1 Promid	Google	$1,920	$919	0.63×	▲6
GPT-4.1midlegacy	OpenAI	$1,680	$980	—	▲1
GPT-6 Solmid	OpenAI	$1,800	$1,100	—	▲1
GPT-6 Sol Promid	OpenAI	$1,800	$1,100	—	▲1
Claude Sonnet 5mid	Anthropic	$1,800	$1,378	—	▲1
GLM-5.2mid	Z.ai	$1,104	$1,862	3.87×	▼16
GPT-4omidlegacy	OpenAI	$2,100	$1,225	—	▲1
GPT-5.6 Terramidlegacy	OpenAI	$2,400	$1,525	—	▲1
GPT-5.4midlegacy	OpenAI	$2,400	$1,525	—	▲1
GLM 4.7 (Cerebras)mid	Cerebras	$1,515	$2,592	7.53×	▼12
Claude Sonnet 4.6mid	Anthropic	$2,700	$2,067	—	—
Claude Sonnet 4.5midlegacy	Anthropic	$2,700	$2,067	—	—
Claude Sonnet 4midlegacy	Anthropic	$2,700	$2,067	—	—
GPT-5.6 Solmidlegacy	OpenAI	$3,600	$2,199	—	—
Claude Opus 5.5mid	Anthropic	$3,600	$2,756	—	—
Claude Opus 4.8mid	Anthropic	$4,500	$3,385	0.96×	—
Claude Opus 4.7midlegacy	Anthropic	$4,500	$3,445	—	—
Claude Opus 4.6midlegacy	Anthropic	$4,500	$3,445	—	—
Claude Opus 4.5midlegacy	Anthropic	$4,500	$3,445	—	—
GPT-4 Turbofrontierlegacy	OpenAI	$7,800	$4,298	—	—
GPT-6 Astrafrontier	OpenAI	$9,000	$5,498	—	—
GPT-6 Astra Profrontier	OpenAI	$9,000	$5,498	—	—
Claude Fable 5.1frontier	Anthropic	$9,000	$6,889	—	—
Claude Fable 5frontierlegacy	Anthropic	$9,000	$6,889	—	—
Claude Opus 5frontierlegacy	Anthropic	$13,500	$10,334	—	—
Claude Opus 4.1frontierlegacy	Anthropic	$13,500	$10,334	—	—
Claude Opus 4frontierlegacy	Anthropic	$13,500	$10,334	—	—
GPT-5.4 Profrontierlegacy	OpenAI	$28,800	$18,727	1.04×	—

Decision evidence · verified 2026-08-27

Agentic tool-loop cost evidence

Frozen inputs, formulas, provenance, and decision boundaries are visible in the initial HTML. Unsupported evidence fails closed as Unavailable.

Recurrence-based context ledger

Formula / scoring rule: Cₙ = system + userₙ + Σ(previous assistant/tool) + tool schema + scratchpad; total bill = Σ(inputₙ×rate + outputₙ×rate).

Provenance: Frozen 8-step loop: 3K initial input, 300 output/step, 1.2K tool result/step; cache hit is explicit.

Frozen fixture / run	Visible inputs	Field-level result	Decision boundary	State
step 1	system 600 + user 3,000 + tools 800; output 300	Input 4,400; output 300; bill = (4,400×5 + 300×15)/1M = $0.0265.	Constant-per-step shortcut is invalid after history grows.	CALCULATED — recurrence row.
step 4	prior history 6,000; current tool result 1,200; schema 800; output 300	Input 11,000; cache-hit prefix Unavailable — provider returned cache usage is absent	Do not apply a cache discount from prompt similarity.	Unavailable — provider returned cache usage is absent
step 8	history 14,400; tool result 1,200; output 300; stop=success	Input 17,000; cumulative input 85,600; cumulative output 2,400.	Cost is task-shaped, not 8 × first-step cost.	CALCULATED — recurrence row.

Module citation: All AI Ask evidence registry (verified 2026-08-27).

Heterogeneous tool settlement tree

Formula / scoring rule: Tool-loop cost = model bill + Σ(tool fee + retry fee + compensating action); unsupported fee remains Unavailable.

Provenance: Frozen search, browser, code, database, and write-action calls; write action is side-effect gated.

Frozen fixture / run	Visible inputs	Field-level result	Decision boundary	State
search / browser	2 searches; 1 browser fetch; 3,100 payload tokens; 1 timeout	Model payload bill calculated; external search fee Unavailable — user tool tariff is not supplied	Do not treat tool fee as zero.	Unavailable — user tool tariff is not supplied
code / database	1 sandbox run; 2 DB reads; 1 retry; 4,800 payload tokens	Retry is counted once; database egress Unavailable — not priced in fixture	External costs remain separate from model tokens.	Unavailable — not priced in fixture
write action	1 side-effecting write; idempotency key w-40; timeout before acknowledgement	Compensating action required; duplicate-effect risk Unavailable — not observable	No successful completion credit until acknowledgement closes.	Unavailable — not observable

Module citation: OpenAI function calling documentation.

Completed-task budget controller

Formula / scoring rule: Cost/completed = total path cost / completed tasks; stopped and escalated tasks remain in numerator.

Provenance: 5/10/20-step caps; planner/executor routing and completion rates are declared scenarios only.

Frozen fixture / run	Visible inputs	Field-level result	Decision boundary	State
5-step cap	25K tasks; 5 steps; completion scenario 82%; budget $0.08	Stopped 4,500; completed 20,500; cost per completed Unavailable — observed completion rate is absent	Scenario completion is not reliability evidence.	Unavailable — observed completion rate is absent
10-step cap	branch factor 1.3; retry ceiling 2; budget $0.12	Escalations and over-budget count Unavailable — not measured on a live run	Do not publish a completion winner from assumptions.	Unavailable — not measured on a live run
planner/executor	cheap planner $0.002/step; premium executor $0.02/step; 70/30 split	Illustrative blended step = .7×.002 + .3×.02 = $0.0074.	Routing cost excludes tool fees and acceptance.	CALCULATED — scenario only.

Module citation: All AI Ask agent workload registry.

Calculate cost per completed agent task →

Prompt caching uses the provider's sourced read multiplier and amortises cache writes over the documented TTL; the largest published read discount is 90%. See the full formula and coverage disclosure →

Alternatives to Amazon Nova Micro →Amazon cost calculator →LLM Chatbot cost →RAG Question Answering cost →

FAQ

Why 8 turns per task?

A representative agent task (research, then act, then verify) typically chains several tool calls before returning a final answer — this is a stated modelling assumption, not a measured average.

Does verbosity compound across turns?

Yes — a chatty model pays its verbosity penalty on every one of the 8 round-trips, not once, so the effect on total task cost is larger here than on a single-call workload.