What's the difference between the Claude Agent SDK and Claude Code?

The Claude Agent SDK is the same agent loop, tools, and context management that runs Claude Code, packaged as a Python or TypeScript library so you build your own agent on it instead of using Anthropic’s own interactive product. Claude Code is that product: the terminal, IDE, and web surfaces where you use Claude yourself, all running the identical loop underneath.

The two diverge past the shared loop. An SDK agent doesn’t get Claude Code’s own system prompt by default, you opt into it explicitly with a preset, so out of the box it’s a different agent, not Claude Code wearing your branding. The SDK also adds one thing the interactive product has no equivalent for: an in-process MCP server, letting you hand Claude a function that runs inside your own application instead of a separate server process whose tool schema can drift out from under a cached client.

sources

keep reading

More on this.

What's the difference between the Claude Agent SDK and Claude Managed Agents?The Claude Agent SDK runs in your own process; Claude Managed Agents is Anthropic's hosted harness with server-side sessions, ineligible for zero data retention.answer →What's the difference between the Claude Agent SDK and Deep Agents?The Claude Agent SDK only runs Claude, embedding Claude Code's own loop; Deep Agents is a model-agnostic LangChain library on the LangGraph runtime, with the same planning and file-tool shape.answer →What's the difference between the Claude Agent SDK and Google's Agent Development Kit (ADK)?The Claude Agent SDK runs only Claude models as Claude Code's own loop; Google's ADK is model-agnostic and built around named multi-agent workflow types.answer →Everything on claude agent SDK evalsThe definition, and every question answered under claude agent SDK evals.concept →

Two ways to run Tessary.

Tessary is an open-source agent reliability platform. Cloud and self-hosted run the same workflow on the OpenTelemetry traces your agent already emits.

Tessary Cloud

We host it for you. Send your first trace with nothing to deploy and no model key.

what's includedper organization
traces
10,000 per calendar month
stored trace data
1 GB
retention
30 days
model credit
$10, one-time, for triage and root-cause analysis
credit card
not required
start for free

Self-hosted Tessary

Run the open-source code on your own infrastructure with one command. Add your own model key for triage and root-cause analysis.

Self-host Tessary for me by following https://github.com/tessaryai/tessary/blob/main/setup.md

docker compose -f oci://docker.io/tessaryai/tessary:compose up -d -y