Yixiang TuandTianyi Cui
e0bd7e1960
Session V4 reserves developer-role messages for incremental model-visible session changes. The role, tool addition/removal blocks, and deferred-loading marker need a durable representation before independent provider and UI integrations can emit or consume them. Known developer events must match an open turn and step; unsupported providers and UI consumers fail explicitly. Request headers already capture full tool definitions. Persisting another ToolSchema in each addition would duplicate Session information and create two definitions that could drift. Additions therefore store toolName, and the containing developer event uses headerSeq to select one earlier known request/header for all its additions. A same-name replacement keeps its historical definition identity through restart, fork and surface changes. Removals require no definition copy, and ordinary developer messages omit headerSeq. Generic sourceEventSeqs remains independent derivation metadata. The rejected inline tool field is optional never with @persistenceReserved. The schema extractor retains that uninhabited slot, so permitting a future value requires a format bump instead of being mistaken for compatible optional metadata. Unrelated optional fields remain additive and readable. Native and Session admission reject missing, forward, non-header, unknown, ambiguous and incomplete referenced definitions, and reject the retired inline tool field. Validate complete schema fields only for referenced definitions, preserving unrelated header behavior and extra JSON metadata. Unknown ignorable records remain opaque. Empty developer nodes retain their surface position without producing a message or shadowing the system head. No automatic emitter, provider activation, UI implementation, or speculative public resolver is added. Keep the core-owned developer source binding beside the introduced role, including the request-only type rejection and attribution round trips. Update consumer guards, SDK/snapshot handling, bilingual owner documentation, and the same unreleased V4 acknowledgement. Keep earlier tool/source migration work and its documentation in the parent. Preserve the existing recorded Cordis inspection generation from the original developer change. Integration keeps the final source layer as the sole parent and preserves master's Messages input filtering, empty-user omission, empty tool results, and system-update placement. Developer/deferred guards still run before conversion. Native V4 admission, header references, reservation declarations, and generic tooling match the validated marker candidate. Parent-owned fixture and generator fixes remain in the parent. Earlier feature validation passed full build, full lint, 41 doc-sync gates, and 16 hygiene gates. The unchanged native implementation retains that evidence. The focused Session/V4/request-input run passes 884 tests across 38 files with 100% statement, branch, function and line coverage for the V3-to-V4 package and Session surface. Consumer tests pass 482 with one existing skip; tool, message and optional-field tests pass 146. Cordis inspection and compaction replays pass in both source and built modes (two cases per mode). Ten invalid referenced-definition/unknown-header controls failed before their scoped guards and pass after them. Reservation validation: the actual generated developer root records tool as optional primitive never. Widening it requires a bump, while traceId remains additive and preserved; all 85 focused reader/classifier tests pass. Final-parent validation: 205 tests across eight provider, type, catalog, Session and native-format files pass. The preserved parent fixture verifies Messages input-history replay; runtime/declaration and parent-owned-file comparisons show no loss during the final rebase. Co-authored-by: Tianyi Cui <[email protected]>
Subsystems
English | 中文
One page per subsystem of the DeepSeek Harness: what it is, the data structures it moves, and — where a ctx service or event scope backs it — a generated Cordis API section carrying its service and event reference. The folder complements architecture.md, which describes behavior across subsystems (the service map, the session/turn/step lifecycle, the event taxonomy); each page here is the reference for one subsystem's vocabulary and wiring.
| Page | Owns |
|---|---|
| boot.md | Current-profile plugin management and launcher reload coordination |
| core.md | how packages/core controls the agent loop: the package-by-package loop description, agent creation and ownership (AgentHandle), the Agent handle's delivery/cancellation/interception contracts, and the repo-wide type patterns (…Map → derived-union, branded ids) |
| llm-streaming.md | the packages/llm conversation types — Message/ContentBlock, the assembled model request, the StreamChunk wire protocol and adapter contract, BlockAssembler, and the LlmAdapter provider contract |
| token-meter.md | immutable scalar and positional replay measurements with consumed-log revisions |
| scope.md | scoped registration identity, dispatch carriers, and the owned Scope context |
| typert.md | Remote invocation descriptors, lookup/Context declarations, Typert registries, and the Host Gateway/Client API boundaries |
| goal.md | persisted goal identity, lifecycle snapshots, activation, change records, and round attribution |
| schedule.md | Session-local reminder records, durable transitions, active views, and ordinary-conversation delivery |
| todo.md | the todo package's whole-list item type, durable event ownership, projection, and open-turn invariant |
| deliverables.md | what a turn hands to the user: PresentedFile deliveries from present and the Host-served WorkspaceChangesSummary of changed files from git snapshots |
| commands.md | the human-command registry service: definitions, adapter discovery, direct invocation, results, and parsing views |
| session.md | the full SessionEventMap variant catalog, TurnEndReason, deriveMessages(), execution enclosure, and standalone events |
| persistence.md | the durability seam: SessionPersistence, the JSONL provider, session/flush, crash recovery, SessionHeader |
| settings.md | the user-settings seam: SettingsNamespace registration, layered resolution (defaults → composition base → user document), owner scopes, hot commits |
| credentials.md | the credential seam: CredentialRef references (never values) in configuration, per-operation resolution, UI-safe CredentialInfo, provider source layers |
| session-query.md | logical records, bounded exact-event reads, relationship traces, semantic filters/documents, and full-text result pages |
| feedback.md | lifecycle-bound per-message feedback records, optimistic versions, sidecar persistence, and the Host Remote contract |
| session-title.md | durable title snapshots, cited source-message seqs, and the asynchronous provider contract |
| session-reference.md | structured cross-session references: SessionReferenceInput/Candidate, prepared message contexts, the stable error taxonomy |
| system-prompt.md | per-assembly context, tool-provider results, prompt sections, and cooperative assembly |
| tools.md | ToolDefinition full fields, the schema DSL, ToolExecution/ToolResult, tool-presentation UI types, and the guarded execution pipeline |
| mcp.md | external MCP connections, scoped tools and resources, server instructions, protocol results, and configuration ownership |
| user-questions.md | the UI-backed human question/answer seam: AskUserQuestionRequest, answer/options vocabulary, provider API, error taxonomy |
| approval.md | the one-shot user-approval seam: ApprovalRequest, ApprovalOutcome, per-session policy, audit events, and answerer contracts |
| office-to-pdf.md | authorized Office-to-PDF conversion, native/WASM engines, and bounded shared reuse |
| attachment.md | durable image identity and metadata, validation inputs, verified reads, and the AttachmentStore seam |
| shell.md | the shell executor seam: ShellExecRequest/Spec, ShellRunResult, background ShellProcess handles |
| subprocess.md | the subprocess seam: fully-explicit SubprocessSpawnSpec, offset-based output readers, unclassified SubprocessOutcome, and the managed DSH_* environment vocabulary |
| ssh.md | the POSIX SSH connection and remote filesystem, subprocess and sandbox providers |
| terminal.md | persistent terminal ids, backend/session contracts, send readiness, bounded reads, and owner-visible snapshots |
| sandbox.md | per-session policy resolution and the process-confinement seam: file-effect modes, execution/provider policies, ConfinedArgv, enforcement and fail-closed errors |
| ptc-runtime.md | the PTC execution seam: PtcRunRequest/Result, binding namespaces, captured logs, the PtcRunFailure taxonomy |
| computer-use.md | exclusive named computer-use provider registration and Cua Driver integration choices |
| browser-use.md | exclusive named browser-use registration, provider choices, and per-Session browser ownership |
| extensions.md | versioned dynamic Cordis Plugins and Packages, Host/Client activation, approval, runtime inspection, and lifecycle teardown |
| filesystem.md | the filesystem seam: FsTarget, read/write/edit outcomes, observed-file state, FsErrorCode |
| lsp.md | the LSP navigation seam: LspQueryRequest/Result, LspProvider/Service, four operations, LspError |
| skills.md | the skill service: discovery priority, SkillSummary/SkillDefinition, session-prefix catalog, model-facing skill loading |
| compaction.md | the compaction seam: the compaction/* session events, CompactionResult, the CompactionEngine interface |
| subagent.md | the subagent seam: the named-provider registry, SubagentStartRequest/Result/Run, the start-time-vs-runtime capability split |
| agent-team.md | Agent Teams: implicit Lead identity, named continuable teammates, durable peer mailbox, and shared task DAG |
| web.md | the web access seam: WebSearchRequest/Result, WebFetchRequest/Result, WebFetchBody, provider availability, WebError |
| spill.md | the spill storage seam: SaveTextSpill, SpillOwner/SpillSource, SpillRef, the branded SpillLocator |
| workflow.md | the workflow seam: WorkflowStartRequest, WorkflowMeta, WorkflowRun/Result, the workflow/* event payloads, WorkflowError fatality |
| jobs.md | the background-job runtime: branded JobIds, the producer contract, consumer views, and ctx.jobs service behavior |
| permission-presets.md | the permission-preset layer: PresetSpec/PresetOption, the derived custom state, the log-only permission/preset event |
| plan.md | plan mode: the log-only plan/mode state, pending-selection flush, PlanModeConfig, the exit_plan_mode review arc |
| invariants.md | the runtime-invariant registry: selection Config, InvariantInstaller/InvariantFailure, the empty-companion contract |
| web-server.md | the HTTP carrier: WebRouteKind/WebRoute, match order, the claimable fallback seat, index taps |
| webhook.md | authenticated provider deliveries, arbitrary programmatic rules, and fire-and-forget Workspace Session creation |
| storage.md | the storage subsystem: the backend contract (StorageBackend), StorageForms, DomainSpec/Domain, domain/changed |
| workspace.md | the workspace registry: Workspace/WorkspaceId, registration and resolution, the session cwd relationship |
| web-client.md | the browser architecture: boot, Remote communication, paired Client models, UI adapters, Conversation assembly, Slots, and reconnect semantics |
| client-modules.md | the web plugin table: dsh.client declarations, WebBootGraph wire composition, the bundle route and index tap |
| slots.md | typed Web UI composition: declaration ownership, cardinality and scope, framework and feature injection, props derivation, and the shipped hierarchy |
| client-resources.md | the client resource model: dsh-resource://<type>/… addresses, protocol providers and ResourceProtocolMap, the useResource global hook and its states, pins and release |
| sidebar-right.md | the right Sidebar: resource and navigation addresses, tab-type registration and routing, the ctx.sidebarRight navigation service, the pane-tab slots and owner props, the resource model, and the Workspace Files service |
| conversation.md | target-neutral Session-event assembly: Context identity, Location data, replay paths, view builders, and target-owned render nodes |
| session-projection.md | the projection seam: SessionProjectionMap, the pure ProjectionDefinition unit, ProjectionSnapshot's consistent cut, the change feed |
| session-telemetry.md | the outbound session-reporting capability seam: SessionTelemetryRecord/SessionTelemetrySeverity, the SessionTelemetrySink contract, and the session-telemetry/record redact waterfall |
Type declarations and their JSDoc on these pages are source-equivalent and drift-checked by
pnpm run verify-type-equiv(see development.md). Ordinary blocks preserve complete declarations;public-apiblocks preserve body-stripped public class declarations. Cordis services and events use each page's generated Cordis API section.