Files
deepseek-harness/packages/agent-loop/README.md
T
Tianyi Cui 7f024a1a9d Document the codebase thoroughly and tighten type safety
Docs: per-folder README.md for packages/ (family overview + one per
package: service, events, API, extension points, TODOs), examples/,
and examples/echo-agent/; folder-level AGENTS.md (+ CLAUDE.md
symlinks) for packages/ and vendor/; module-level doc comments in
every packages/*/src file; richer JSDoc on all exported API
(event side effects, disposal contracts, error behavior). Root
AGENTS.md gains a "Type Safety and Documentation" policy section:
the codebase aims to be very type-safe and well documented; type
gymnastics are acceptable in core packages when they improve
plugin-author DX; verbose docs are fine as long as they stay strictly
in sync with the code.

Type safety: removed the upstream-inherited "noImplicitAny": false
from tsconfig.base.json — packages/* now compile under full strict
mode; vendor/loader and vendor/include set it locally (vendor/cordis
already did). Eliminated every `: any` / `as any` from packages and
examples (catch clauses use unknown + a CodedError narrowing type;
event data access uses discriminated-union narrowing).

Typed tool schemas: new @deepseek-ai/dsh-tools schema DSL —
SchemaSpec with per-property `required: true` booleans, type-level
InferArgs<S>, a runtime SchemaSpec → JSON Schema converter, and
defineTool() so first-party tools get typed execute(args) with zero
casts (raw JSON Schema still accepted for MCP interop; chosen over
schemastery because it targets JSON Schema generation directly).
echo-tool and all test tools migrated; +7 tests.
2026-06-11 13:01:00 +08:00

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2.7 KiB
Markdown

# dsh-agent-loop
THE concrete agent plugin: `LoopAgent` and the loop driver. Implements the
`Agent` interface and drives the session/turn/step lifecycle.
This is the only package in the harness that contains concrete loop logic.
Everything else is an abstract service or a plugin against extension seams —
new behavior goes into plugins, not here.
## Service: `AgentLoop` (ctx key: `agentLoop`)
### Public API
- `ctx.agentLoop.create(id: string, options?: AgentOptions): LoopAgent`
Create an agent, start its loop, and register it in `ctx.agents`. Disposed
with the calling fiber.
### Injected services
`agents`, `sessions`, `llm`, `tools`, `systemPrompt` — all five interface
services.
### Configuration (schemastery)
```ts
Config: {
agents: Array<{
id: string // required
model?: string
systemPrompt?: string
}>
}
```
Agents listed in config are auto-created at startup.
### Classes
- `LoopAgent` — the concrete `Agent` implementation. Owns the inbox (`Inbox`),
the per-step `AbortController`, and the loop driver. Everything observable
happens through session events and the `agent/*` event taxonomy.
- `Inbox` — per-agent queued + steering FIFOs (`enqueue`, `steer`, `drainQueued`,
`drainSteering`, `waitForQueued`).
### Loop lifecycle (`loop.ts`)
One invocation of `runLoop()` drives one agent for its whole lifetime:
```
forever:
wait for queued messages (idle)
TURN (error-contained):
drain queued → session('user/message') → 'turn/start'
STEP loop:
drain steering
assembly = systemPrompt.assemble()
request = waterfall agent/request
stream llm.stream(request) → session('assistant/chunk')
message = waterfall agent/step-result
session('assistant/message')
each tool-call: session('tool/call') → tools.execute() → session('tool/result')
drain steering → session('steering/message')
cont = waterfall agent/turn-continuation
if !cont: break
session('turn/end')
await session/flush
re-enqueue leftover steering as queued
idle unless more queued
```
Error containment: a throwing plugin ends the **turn**, never the loop. Dispose
mid-turn emits `agent/status('disposed')` and ends with reason `disposed`.
### What is NOT here
Everything that goes beyond "call the model, run the tools, repeat" belongs to
plugins listening on the event taxonomy:
- Hooks: `agent/request`, `agent/step-result`, `tools/execute`, `agent/turn-continuation`
- Compaction: `agent/request`
- Sandbox, permission, plan mode: `tools/execute`
- Sub-agents: TODO seam on `AgentLoop.create()`
- Persistence: `session/event` + `session/flush`
- UI: `agent/stream-chunk` + `agent/*` events