New @deepseek-ai/dsh-invariants plugin (pure listeners, off in prod) asserts
the event taxonomy at runtime — seq monotonicity, turn/step nesting, a
tool/result needs a prior tool/call (NOT the converse), legal agent/status
transitions — and deep-freezes logged event data so mutating history throws.
Seeded sessions are checked + frozen on session/created.
The real RFC 008 fix is always-on: deriveMessages now structured-clones the
content it emits, so the loop's sanctioned request/adapter mutation can no
longer reach back and rewrite the append-only log. The pervasive
DeepReadonly<T> type flip is rejected (compile-only, high-noise, castable) —
recorded in ADR 0012, which folds in RFC 008. Wired into both demos.
- enum membership now checked uniformly for all SchemaTypes, mirroring the
converter which emits `enum` regardless of type (was string-only)
- checkValue switch ends in assertNever per the closed-union convention
- sync the adding-a-tool cookbook to the validate-for-you behavior
- soften ADR 0011's property-test claim (RFC 001 not yet landed)
defineTool now runs validateArgs against the SchemaSpec before execute, so a
malformed model call returns a self-correctable isError result listing the
violations instead of reaching the typed body untyped-in-practice. The
validator mirrors schemaSpecToJsonSchema semantics exactly (required from
required:true only, extra keys allowed, default not applied, object/array
without properties/items only type-checks, enum membership).
tool-bash's hand-rolled type/required checks (carrying the TODO(RFC 005)
stopgap note) are slimmed to just the value constraints the DSL can't express
(non-empty strings, positive timeout). Graduates RFC 005 pt 1 to ADR 0011.
- AGENTS.md Commands: fix typecheck/build descriptions; add lint, lint:fix,
test:coverage, knip, publint, hygiene (were undocumented).
- Drop the bare `yarn demo` for explicit `demo:echo` + `demo:coding`; update
README, examples READMEs (and document coding-agent in examples/README).
- New cookbook guide: adding-a-vendored-package.md (the missing "add" half of
vendor/README's update-only procedure).
- architecture.md: add a table-of-contents and extract the Extension cookbook
to docs/cookbook/extension-cookbook.md (link-preserving); drop the completed
"restructure this document" TODO.
- ADR 0009 (capability seams) + 0010 (twin LLM adapters), and a "when to write
an ADR" standard in adr/README.
- Add a committed dsh-code-review skill under .agents/skills, exposed to Claude
Code via a tracked .claude/skills symlink (gitignore carve-out).
Hard line breaks mid-paragraph make docs harder to edit and diff — a
one-word change reflows and re-diffs the whole paragraph. Reflow all
tracked non-vendor Markdown (plus vendor/AGENTS.md) so each prose
paragraph is a single line; soft-wrapping is the editor's job. Fenced
code, tables, and list structure are preserved (wrapped list items fold
to one line per bullet). Documents the convention in AGENTS.md.
The first real LlmAdapter implementations, shipped as a deliberate pair:
same models and wire protocol, completely different internals, so the
StreamChunk protocol is verified across independent implementations.
- dsh-llm-deepseek: hand-rolled fetch + SSE parser + chunk-translation
state machine against the official chat-completions format (thinking
mode via top-level thinking/reasoning_effort; the empty-string
reasoning_content first chunk; usage attached to the finish chunk or
trailing; reasoning_content passback on tool-call turns; disjoint
cache-token accounting).
- dsh-llm-pi-ai: the same endpoint through @earendil-works/pi-ai,
mapping its event vocabulary (parsed tool arguments, in-stream error
events, folded reasoning tokens) onto the same chunks.
The agent loop now honors the in-band error path: an adapter that ends
its stream with finish {kind:error|aborted} (the only option for
adapters that can't throw mid-stream, like pi-ai) is translated into a
step error, so the turn ends error/aborted with a logged error event
instead of a normal completed assistant message. This makes the
StreamChunk error contract real for both adapters; docs/architecture.md
and the StreamChunk doc are updated accordingly.
New yarn test:e2e (vitest.e2e.config.ts, *.e2e.ts) runs key-gated
real-API matrices for both adapters across V4 Flash/Pro and all
thinking/effort levels; it self-skips without DEEPSEEK_API_KEY. Unit
suites run against local node:http mock SSE servers at 100% per-file
coverage.
Three packages following the new capability-seam pattern (interface /
implementation / consumer, now documented in docs/architecture.md):
- dsh-bash: abstract BashExecutor service (ctx.bash) + vocabulary types.
- dsh-bash-local: local subprocesses — bash -c per call in a detached
process group, SIGTERM→SIGKILL group kills, tail-keep truncation with
full-stream spill files, model-friendly env, background task registry.
- dsh-tool-bash: the bash / bash_output / bash_kill tool schemas with
runtime arg validation and background completion notices via
agent.inject(). Non-zero exits are reported, not errored.
Design surveyed against the bash tools of Claude Code, OpenCode, Codex,
and pi (notes in the package READMEs). Permissions/sandbox stay TODO on
the tools/execute waterfall seam; stateful-shell alternatives recorded
in run.ts.
assertNever (dsh-llm) marks unreachable defaults on CLOSED unions:
adding a StreamChunk variant now breaks compilation at
BlockAssembler.push, and a value escaping its type at runtime throws
with diagnostics. The module doc and a new AGENTS.md convention spell
out the dividing line: merge-extensible unions (SessionEventMap,
ContentBlockMap, …) must NOT use assertNever — plugin-added variants
are valid unknown values there; handle known cases and fall through
with a comment.
Nominal string types via a unique-symbol brand (zero runtime cost):
an AgentId can no longer be passed where a CallId is expected. Each
core package brands the IDs it owns — CallId in dsh-llm (tool-call
correlation across blocks, chunks, session events, and execution
results), SessionId in dsh-session, AgentId in dsh-agent. Construction
goes through same-named factory functions; public string-in APIs
(sessions.create, agentLoop.create) keep accepting plain strings and
brand internally. Policy note in the brand module: brand IDs that
cross package boundaries, not every string.
Flat config with two layers. Correctness (type-checked): the headline
rules for this codebase are no-floating-promises / no-misused-promises
(a lost promise in the agent loop is our primary bug class),
switch-exhaustiveness-check (we switch over merge-extensible unions
everywhere), no-unnecessary-condition, require-await, and
no-explicit-any. Style (@stylistic): 2-space, no semicolons, single
quotes, trailing commas, max-len 140 — the existing house style, now
enforced instead of drifting between agents. vendor/ is excluded
(vendored source keeps upstream style); tests relax the rules that
fight test ergonomics (non-null assertions after expects, async mock
signatures, non-Error throws).
Code adjusted to pass: registry disposers wrap ctx.effect's
promise-returning disposer behind a sync () => void (our public API),
BlockAssembler gains an invariant-checking mustGet instead of non-null
assertions, lastTurnNumber uses findLast, waterfall tails return
Promise.resolve instead of async-without-await arrows, and the two
deliberate suppressions (non-exhaustive derivation switch, unbound
execute pass-through) carry justification comments.
yarn lint / yarn lint:fix added.
tsconfig.base.json adds noUncheckedIndexedAccess,
exactOptionalPropertyTypes, noImplicitOverride,
noFallthroughCasesInSwitch, noUnusedLocals, and noUnusedParameters on
top of strict. Vendored packages opt out of the new flags locally
(their tsconfigs are ours to regenerate; their source is not), keeping
upstream-sync friendliness.
Our code fixed accordingly: index accesses acknowledge undefined
(assembler flush cursors, lastTurnNumber); optional properties are
omitted instead of set-to-undefined (GenerateResult.usage,
ToolDefinition.strict, GenerateOptions.system/tools, error payloads
via an errorData helper); Session.onAppend is explicitly
`(…) => void | undefined`; tests and examples updated for unused
parameters and indexed access.
InferArgs now produces genuinely optional keys: required/optional
properties are split at the key level (RequiredKeys + mapped `?`), so
{ limit: { type: 'number' } } infers as { limit?: number } and callers
can omit it — previously the key stayed required with `| undefined`.
Array item inference recurses (arrays of objects infer their element
shape instead of Record<string, unknown>), matching the generated
JSON Schema.
Tool execution error reporting handles non-Error throws again:
`throw { message: 'denied' }` reports the message instead of
"[object Object]" (errorMessage helper).
The new schema tests now actually typecheck: schema literals use
`satisfies SchemaSpec` (the standalone-literal widening made
schemaSpecToJsonSchema reject the suite's own examples), and the
ToolSchema probe cast goes through unknown. Tests-and-examples
typechecking is now part of `yarn typecheck` via the new
tsconfig.typecheck.json (resolves vendor packages by their built
declarations, so vendor's relaxed-strictness source stays out of
scope) — vitest never typechecks, so this gate is what catches such
breakage. +4 regression tests (typed omission, array-of-objects
inference both type- and runtime-level, non-Error throw message).
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.
High (loop pipeline): agent/step-result now runs before the
assistant/message append so the session log records what tool dispatch
actually uses; abort is honored between tool calls, not just
mid-stream; steering drains at step start, pending steering overrides
a negative turn-continuation decision (/goal pattern), and leftover
steering is re-enqueued as queued messages so it is never stranded;
exceptions from turn-continuation listeners and session/flush are
contained to the turn (error event + agent/error) instead of killing
the driver loop.
Medium: disposal emits agent/status('disposed') and mid-turn disposal
records reason 'disposed'; duplicate LLM adapter registration throws
(all-or-nothing); SessionEvent is a real discriminated union (casts
removed); model-less agents fail with a clear actionable error unless
agent/request supplies a model.
Low: agent/queued and agent/steering carry the resolved MessageSource;
streamBlocks() yields strictly in stream order and flushes delta-only
blocks (matches generate()); BlockAssembler freezes blocks on
block-end and ignores stragglers from malformed streams; turn
numbering is a counter seeded from the log (fork-safe); LoopAgent's
stop disposer is infallible (a throwing status listener cannot skip
registry cleanup); AgentLoop.create uses a generator effect so stop
and unregister are independent disposables; SessionStore wires
onAppend inside its effect.
21 regression tests added (review-fixes.spec.ts), organized by
finding. Docs updated: loop pseudocode (status emissions, ordering,
error containment, steering guarantees) and waterfall composition
caveat in docs/architecture.md; AGENTS.md notes that excessive tests
are welcome.
@deepseek-ai/dsh-llm: provider-neutral content-block vocabulary
(merge-extensible maps), raw StreamChunk protocol, ToolSchema,
abstract LlmAdapter, LlmService adapter registry, BlockAssembler.
@deepseek-ai/dsh-session: event-sourced Session (append-only log,
deriveMessages; context/steering render as tagged envelopes),
SessionStore, session/event + awaited session/flush durability seam.
@deepseek-ai/dsh-system-prompt: ordered sections + tool-schema
providers; assemble() through the system-prompt/assemble waterfall.
Tool schemas are part of the assembly by design.
@deepseek-ai/dsh-tools: tool registry feeding schemas into the
assembly; execute() through the tools/execute waterfall (the single
sandbox/permission/hook seam).
@deepseek-ai/dsh-agent: Agent interface (send/steer/inject/abort,
spawn/fork TODO seams), AgentRegistry, and the full agent/* event
taxonomy so plugins never depend on the concrete loop.
Tianyi Cui