OpenAI Agents SDK vs Claude Agent SDK: Which Should You Use in 2026?
Neither SDK charges for itself — you pay only for model tokens and tool calls, so the choice comes down to architecture: the OpenAI Agents SDK (Python/TypeScript, 27K+ GitHub stars) is built around native sandbox execution and long-horizon file/command work, while the Claude Agent SDK (Python/TypeScript, 7.3K+ stars) ships the same tool-rich loop that powers Claude Code, ideal for coding agents with file and shell access. Entry-level model costs are comparable — GPT-6 Luna at $0.10 per 1M input tokens versus Claude Haiku 4.5 at $1 per 1M input tokens. Whichever you pick, agent skills can extend what your agents do — SkillzBench is building a free directory and free MCP connector for exactly that.
TL;DR
- Neither SDK has its own fee — OpenAI states the Responses API and agent tooling are included with standard API model pricing, and the Claude Agent SDK bills only Claude API token rates.
- Cheapest agent-capable models: GPT-6 Luna at $0.10 input / $0.50 output per 1M tokens (Standard) vs Claude Haiku 4.5 at $1 input / $5 output per 1M tokens.
- OpenAI's April 2026 Agents SDK update added native sandbox execution, a Manifest workspace abstraction, configurable memory, and Codex-like filesystem tools.
- The Claude Agent SDK ships the same tools, agent loop, and context management that power Claude Code, including built-in file, shell, code-editing, and web-search tools.
- Hosted tool calls add up: OpenAI web search is $10 per 1,000 calls (plus result tokens at model rates); Anthropic web search is also $10 per 1,000 searches.
- OpenAI charges a long-context tier above 272,000 input tokens (roughly double), while Anthropic does not charge a long-context premium.
- Claude Managed Agents sessions add a $0.08 per active session-hour runtime fee; idle time is free, but Batch API discounts and Fast Mode pricing don't apply to sessions.
Head to head
| Dimension | Claude Agent SDK | OpenAI Agents SDK |
|---|---|---|
| Pricing | No SDK fee; Haiku 4.5 from $1/1M input, $5/1M output; managed sessions +$0.08/active hour | No SDK fee; GPT-6 Luna from $0.10/1M input, $0.50/1M output; Batch/Flex at 50% 🏆 |
| Ease of use | Ships Claude Code's exact loop and tools — no tool implementation required on your side | Turnkey harness built for OpenAI models; pip-installable; production-tested at Oscar Health |
| Built-in tools | File reading, shell commands, code editing, web search, codebase pattern matching built in | MCP, skills, AGENTS.md, shell, apply-patch, filesystem tools; hosted web search $10/1k calls, file search $2.50/1k calls |
| Sandbox / execution | Managed Agents runtime folds code-execution container costs into the $0.08/session-hour fee | Native sandbox execution with built-in support for Blaxel, Cloudflare, Daytona, E2B, Modal, Runloop, Vercel; Manifest workspace abstraction 🏆 |
| Languages | Python, TypeScript | Python, TypeScript |
| Ecosystem | 7.3K+ GitHub stars; Anthropic-native with custom base URL gateway support | 27K+ GitHub stars; storage integrations with AWS S3, GCS, Azure Blob, Cloudflare R2 🏆 |
| Long-context cost | No long-context premium; same per-token rate regardless of context length 🏆 | Roughly 2x pricing above 272K input tokens (e.g., GPT-6 Astra: $10 → $20/1M input) |
| Model flexibility | Claude models; custom base URL for gateways | OpenAI models; custom endpoints supported |
The contenders
The OpenAI Agents SDK is OpenAI's open-source orchestration layer for building production agents, available in Python and TypeScript with 27K+ GitHub stars. Launched alongside the Responses API in March 2025 and substantially updated in April 2026, it provides a model-native harness with configurable memory, sandbox-aware orchestration, Codex-like filesystem tools, and standardized integrations with emerging agent primitives: tool use via MCP, progressive disclosure via skills, custom instructions via AGENTS.md, code execution via the shell tool, and file edits via apply patch. The April 2026 release added native sandbox execution so agents can run in controlled computer environments, with built-in support for Blaxel, Cloudflare, Daytona, E2B, Modal, Runloop, and Vercel sandboxes, plus a Manifest abstraction for mounting local files and storage from AWS S3, Google Cloud Storage, Azure Blob Storage, and Cloudflare R2. OpenAI positions it as turnkey yet flexible, and customers like Oscar Health report using it for production clinical-records workflows. Note that OpenAI is winding down the no-code Agent Builder and Evals surfaces from November 30, 2026, pointing developers to the code-first Agents SDK instead.
pricing 0.1
- + No separate SDK or agent-platform fee — you pay only model tokens and hosted tool calls
- + Cheapest agent-capable model tier in this comparison: GPT-6 Luna at $0.10/1M input and $0.50/1M output (Standard)
- + Native sandbox execution out of the box across seven sandbox providers, instead of piecing together your own execution layer
- + Production-proven: Oscar Health used the updated SDK to automate a clinical records workflow previous approaches couldn't handle reliably
- + Prompt caching at a tenth of fresh input rates meaningfully cuts costs on multi-turn agent loops that re-send growing context
- + Batch and Flex modes halve token costs for non-urgent agent workloads
- − Long-context pricing kicks in above 272,000 input tokens at roughly double the short-context rate — a trap for document-heavy agents
- − Hosted tool surcharges stack: web search at $10/1k calls plus result tokens, file search at $2.50/1k calls plus $0.10/GB/day storage, containers billed per session
- − Model-agnostic flexibility is limited — the harness is built to align with OpenAI models' operating patterns
- − The no-code Agent Builder and Evals surfaces are being retired November 30, 2026, forcing code-first migration for teams that used them
- − Data-residency endpoints carry a 10% uplift for models released on or after March 5, 2026
https://openai.com/index/the-next-evolution-of-the-agents-sdk/
The Claude Agent SDK gives developers the same tools, agent loop, and context management that power Claude Code, programmable in Python and TypeScript. It ships built-in tools for reading files, running shell commands, editing code, searching the web, and pattern matching across codebases — no tool implementation required on your side, which makes it the most turnkey option for coding-agent workloads. It has 7.3K+ GitHub stars and runs Anthropic-native with custom base URL support for gateways. Anthropic also offers Claude Managed Agents, a hosted runtime that runs the agent loop for you: sessions are billed at standard Claude API token rates plus $0.08 per active session-hour, with idle time free and code-execution container costs folded into the runtime fee. Anthropic's model lineup spans Claude Opus 5 ($5/1M input, $25/1M output), Claude Sonnet 5 ($3/1M input, $15/1M output from September 1, 2026), and Claude Haiku 4.5 ($1/1M input, $5/1M output). Notably, Anthropic does not charge a long-context premium, unlike OpenAI's 272K-token cliff. A worked example from Anthropic's documentation prices a one-hour Opus 5 coding session (50K input, 15K output tokens) at $0.705 total.
pricing 1
- + Zero tool implementation required — file, shell, code-editing, web-search, and pattern-matching tools ship built-in
- + Proven harness: it's the same loop and context management that powers Claude Code in production
- + No long-context token premium, unlike OpenAI's roughly 2x pricing above 272K input tokens
- + Managed Agents idle time is free — sessions waiting on humans, tool approvals, or scheduled resumes don't burn runtime charges
- + Code-execution container costs are folded into the session runtime fee rather than billed separately
- + Cache reads are cheap (e.g., $0.10/MTok on Haiku 4.5), rewarding multi-turn agent loops
- − Cheapest model tier (Haiku 4.5 at $1/1M input) is 10x the price of OpenAI's GPT-6 Luna at $0.10/1M input
- − Claude Sonnet 5 pricing rose from $2/1M input to $3/1M input effective September 1, 2026
- − Managed Agents sessions lose standard API discounts: no Batch 50% discount, no Fast Mode pricing, no data-residency multipliers
- − Web search still costs $10 per 1,000 searches on top of tokens, and the $0.08/session-hour runtime fee compounds across many long-running agents
- − Claude-only — no model flexibility within the harness, and a smaller GitHub community (7.3K+ stars) than OpenAI's SDK
Verdict
Winner: none
The two SDKs optimize for different jobs: OpenAI's for sandboxed, long-running document and system work; Claude's for tool-rich coding agents. Cost differences are model-driven, not SDK-driven.
| Option | Overall | Breakdown |
|---|---|---|
| OpenAI Agents SDK | 8.2 | : 8: 9: 8: 8 |
| Claude Agent SDK | 8 | : 7: 9: 9: 7 |
Pricing compared: what an agent actually costs to run
Architecture: sandbox-first vs tool-first
Small-business fit: which one gets you to production faster
Which should you pick?
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FAQ
Do the OpenAI Agents SDK or Claude Agent SDK cost money themselves?
No. OpenAI states that the Responses API and its agent tooling are included with standard API model pricing with no separate fee, and the Claude Agent SDK bills only standard Claude API token rates. Your costs come entirely from model tokens, hosted tool calls, and execution infrastructure — so budget for usage, not for the SDK.
Which is cheaper for a small business: OpenAI or Claude for agents?
At the entry tier, OpenAI: GPT-6 Luna costs $0.10 per 1M input tokens versus $1 per 1M for Claude Haiku 4.5 — a 10x gap. At the flagship tier it flips: Claude Opus 5 is $5/$25 per 1M tokens versus $10/$50 for GPT-6 Astra. Also note OpenAI roughly doubles rates above 272K input tokens while Anthropic has no long-context premium, so your workload shape matters as much as the headline price.
What is the $0.08 per session-hour fee on Claude Managed Agents?
Claude Managed Agents bills standard Claude API token rates plus $0.08 for each hour a session spends in a running state, tracked to the millisecond. Idle time — waiting on a human, a tool approval, or a scheduled resume — is free. The fee barely affects short, high-throughput sessions but compounds across many long-running agents, and Batch API discounts and Fast Mode pricing don't apply to managed sessions.
Which SDK is better for building a coding agent?
The Claude Agent SDK is purpose-built for this: it ships the same tools, agent loop, and context management that power Claude Code, including built-in file reading, shell command execution, code editing, web search, and codebase pattern matching, with no tool implementation required on your side. Anthropic's own worked example prices a one-hour Opus 5 coding session at $0.705 total.
Can I use agent skills with either SDK?
Yes — both SDKs support the same emerging primitives, including MCP tool use and skills-based progressive disclosure (OpenAI also standardizes AGENTS.md custom instructions). SkillzBench, currently in pre-launch, is building a free directory and free MCP connector that discovers skills, pins each version to a commit SHA, security-scans them, and benchmarks them in a sandbox so you can equip your agent with skills that are proven rather than risky — published research found roughly 26% of skills carry at least one vulnerability.
Is OpenAI's Agent Builder still available?
Not for long. OpenAI is winding down Agent Builder and Evals — from November 30, 2026 they won't be available, and OpenAI now points developers to the code-first Agents SDK or Workspace Agents in ChatGPT instead. If you built on the no-code canvas, plan a migration before that date.