FAQ
Start with these ten questions
A compact starting point for readers and generative search. Every answer uses the same source-level names as the rest of the Brickbook.
Which DeepSeek Harness version does this Brickbook cover?
The content is aligned with the official dsh-v0.1.1-rc.2 release at commit b150a55, published on 2026-08-21. That source snapshot contains 227 packages/*/package.json manifests; the directory curates the core and representative plugins instead of flattening all 227 into one list.
What is DeepSeek Harness?
DeepSeek Harness (dsh) is an open-source agent runtime. It does not hard-code a model into its core: model adapters, tools, sessions, sandboxes, loops, and UI are all plugins. Its two central ideas are Everything is a plugin and Every run is traceable.
What does Cordis do in dsh?
Cordis is the baseplate. Plugins contribute Services, typed events, and reversible effects to a shared Context. Registrations are automatically undone when a fiber is disposed. There is no privileged kernel to patch; extend the system by mounting a plugin beside the others.
What does Everything is a plugin mean?
Every capability is a replaceable brick. Change the LLM adapter without changing the loop; replace the filesystem provider and Bash, PTY, and LSP can follow. Select, replace, and extend through configuration instead of editing dsh source.
What does model-visible means logged mean?
Everything that reaches a model request must be reconstructible from the append-only Session log. deriveMessages() projects surface events instead of maintaining a second chat array. This runtime invariant is the basis of Every run is traceable.
How are sandbox and E2B different?
sandbox.confine wraps local argv—a safety gate inside this room. E2B is another fs + subprocess provider pair, like moving the whole playroom into the cloud. A fence is not a move; hands and feet must share one execution world.
Are Cordis inject and Agent.inject() the same?
No. Cordis inject declares plugin dependencies and waits for required services before activation. Agent.inject() puts a message into inbox.next-step without waking the driver. They share a name but do entirely different jobs.
How are scope and isolate different?
scope is a set of per-agent lockers, not a sandbox. isolate gives a child Context its own service with the same name—its own classroom tap. Agent presets use isolate to change outfits.
How do a turn and a step differ?
A step is one model request plus the tools it calls. A turn contains zero or more steps: it opens before the first input is claimed and closes when no work remains. Even a rejected first claim leaves a durable zero-step turn.
Can dsh read images, and do images land in the session log?
Yes, but the log stores only a reference. ctx.attachments.saveImage validates and normalizes the image, commits it content-addressed, and returns an ImageAttachmentRef; base64, browser paths, and provider URLs never reach a SessionEvent. tool-fs registers read_image only while a durable attachment store is mounted, and the routed model must declare image input; dsh-llm-deepseek then resolves each reference into a Files API id and falls back to inline data URLs for the whole request when resolution fails.
Need to check a name?Open the glossary. Looking for an extension hook?Read the two principles.