AI Agent Cost Index

AI Agent Cost Index — July 2026

Most AI agent pricing assumes a single API call. Real agents make multiple calls, accumulate context, retry on failure, and use tools. This index shows the true cost.

Methodology

Cost calculated for 5 agent archetypes (see table below). Each run includes: system prompt + conversation + tool definitions (input), response (output), tool results re-injection (input), retry allowance (10%). Prices from official provider pages July 2026.

Agent Archetype Cost Table

Agent type Description Input/run Output/run Calls/run Cost on GPT-4o Cost on Plugsky
Simple RAGSingle question + context retrieval4K5001$0.0015$0 (flat)
ResearchMulti-search + synthesis15K4K4$0.008$0 (flat)
CodingGenerate + review + fix20K8K3$0.013$0 (flat)
Customer supportContext + tool calls + resolution10K2K3$0.005$0 (flat)
Multi-agent5 agents × 3 rounds of coordination50K20K15$0.045$0 (flat)

Per-run costs assume GPT-4o at $2.50/$10 per MTok (input/output) and Plugsky flat pricing. Updated Jul 2026.

Monthly cost projections

Here's what these agent archetypes cost at various volumes across major providers:

Runs/month GPT-4o Claude 3.5 Sonnet Gemini 2.5 Pro Plugsky
1K$5 – $45$3 – $40$2 – $20$20 (Hobby)
10K$50 – $450$30 – $400$20 – $200$50 (Starter)
100K$500 – $4,500$300 – $4,000$200 – $2,000$100 (Builder)
1M$5,000 – $45,000$3,000 – $40,000$2,000 – $20,000$500 (Scale)

Ranges reflect the spread between Simple RAG (cheapest) and Multi-agent (most expensive) archetypes. Plugsky pricing is per-user per-month flat rate. Updated Jul 2026.

Hidden costs

Per-token pricing models hide several cost multipliers that only appear when you run real agents:

  • Retries — adds 10–30% to token count. Every failed tool call, rate-limit hit, or hallucinated output requires a retry that costs the same as the original.
  • Context accumulation — each round adds the full conversation history back as input. A 5-round agent with 10K context per round burns 50K+ input tokens total, not 10K.
  • Tool execution — tool results (search results, file contents, API responses) are re-injected as input for the next call. A 2K web search result becomes 2K additional input tokens.
  • Multi-agent overhead — agents talk to each other. Each coordination round is a full inference call for every agent involved. Five agents × 3 rounds = 15 separate calls.
  • Rate limit retries — when you hit provider rate limits, exponential backoff wastes time and retries waste tokens. At scale this adds noticeable overhead.

Plugsky advantage

Flat pricing means unlimited runs. For multi-agent or high-volume agent systems, Plugsky can be 10–100× cheaper than per-token providers.

A team running 100K multi-agent runs/month on GPT-4o would pay roughly $4,500. On Plugsky Builder ($100/month), the same workload costs the same flat rate — regardless of agent complexity, retries, or context size. The more agents you run, the more you save.

Download the data

Copy the table below for your own analysis:

Agent type,Description,Input/run,Output/run,Calls/run,GPT-4o cost,Plugsky cost Simple RAG,Single question + context retrieval,4K,500,1,$0.0015,$0 (flat) Research,Multi-search + synthesis,15K,4K,4,$0.008,$0 (flat) Coding,"Generate + review + fix",20K,8K,3,$0.013,$0 (flat) Customer support,"Context + tool calls + resolution",10K,2K,3,$0.005,$0 (flat) Multi-agent,"5 agents × 3 rounds of coordination",50K,20K,15,$0.045,$0 (flat) Runs/mo,GPT-4o,Claude 3.5 Sonnet,Gemini 2.5 Pro,Plugsky 1K,$5-$45,$3-$40,$2-$20,$20 (Hobby) 10K,$50-$450,$30-$400,$20-$200,$50 (Starter) 100K,$500-$4,500,$300-$4,000,$200-$2,000,$100 (Builder) 1M,$5,000-$45,000,$3,000-$40,000,$2,000-$20,000,$500 (Scale)

Limitations

Actual costs vary based on your specific agent architecture, model choice, and usage patterns. Context windows vary by model — GPT-4o supports 128K, Claude 3.5 supports 200K, Gemini 2.5 supports 1M. Plugsky comparison assumes the same agent architecture and model tier across providers. Per-token pricing is subject to change by providers.

Frequently asked questions

What's the most expensive part of AI agents?

Context accumulation and multi-agent coordination. A single agent call is cheap ($0.001–$0.01), but agents that loop, retry, or coordinate with other agents multiply the cost by 5–20×. In a multi-agent system, most of the cost is input tokens from re-injecting full conversation history each round.

Is Plugsky cheaper for agents?

Yes — for any agent that makes more than one call per run. Plugsky's flat pricing means the per-run cost is effectively $0 regardless of how many calls, retries, or tool results your agent uses. For multi-agent systems or high-volume agent deployments, Plugsky is typically 10–100× cheaper than per-token providers.

How many calls does a typical agent make?

A simple RAG agent makes 1 call. A research agent making 4 searches with synthesis makes 4–5 calls. A coding agent that generates, reviews, and fixes code makes 3–5 calls. A multi-agent system with 5 agents and 3 coordination rounds makes 15+ calls. Each call is a separate API request with its own token cost.

How do retries affect agent costs?

Retries add 10–30% to your token bill on per-token providers. Every time an agent makes a bad tool call, hits a rate limit, or produces invalid output, the retry costs the same as the original. On Plugsky, retries are free — your flat rate covers unlimited attempts.

What agent archetype should I use for cost estimation?

Start with the archetype closest to your use case. Simple RAG for Q&A bots, Research for analysis/reporting agents, Coding for development agents, Customer support for ticket-handling agents, and Multi-agent for complex orchestration workflows. If you're unsure, use the Coding or Customer support numbers — they're the most representative of real-world agent workloads.

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