deepseek-harness/docs/capability-seams.md

Capability Seams And Core Services

A service can be a core spine service, a swappable capability seam, or a bundle/composition point. The graph shows the package that owns the service declaration, known implementation packages, and packages that consume the service directly.

flowchart LR
  pkg_llm["llm"]
  svc_llm["ctx.llm<br/>LLM adapter registry"]
  pkg_llm_deepseek["llm-deepseek"]
  pkg_llm_pi_ai["llm-pi-ai"]
  pkg_llm_replay["llm-replay"]
  pkg_agent_loop["agent-loop"]
  pkg_compact_basic["compact-basic"]
  pkg_token_meter["token-meter"]
  svc_tokenMeter["ctx.tokenMeter<br/>Replay token measurement"]
  pkg_compact_tool_result_prune["compact-tool-result-prune"]
  svc_toolResultPrune["ctx.toolResultPrune<br/>Model-free tool-result pruning"]
  pkg_session["session"]
  svc_sessions["ctx.sessions<br/>In-memory session store"]
  pkg_agent["agent"]
  pkg_cli_demo["cli-demo"]
  pkg_session_persistence["session-persistence"]
  pkg_session_query["session-query"]
  pkg_session_query_sqlite["session-query-sqlite"]
  pkg_subagent_inprocess["subagent-inprocess"]
  pkg_invariants["invariants"]
  svc_invariants["ctx.invariants<br/>Package-owned invariant registry"]
  pkg_scope["scope"]
  svc_sessionPersistence["ctx.sessionPersistence<br/>Durable session persistence seam"]
  pkg_session_persistence_jsonl["session-persistence-jsonl"]
  pkg_session_persistence_sqlite["session-persistence-sqlite"]
  pkg_tool_bash["tool-bash"]
  pkg_hooks_claude["hooks-claude"]
  pkg_hooks_codex["hooks-codex"]
  pkg_storage["storage"]
  svc_storage["ctx.storage<br/>Non-session storage hub"]
  pkg_storage_json["storage-json"]
  pkg_storage_sqlite["storage-sqlite"]
  pkg_storage_domain["storage-domain"]
  svc_storageDomain["ctx.storageDomain<br/>Domain data facility"]
  pkg_workspace["workspace"]
  svc_workspace["ctx.workspace<br/>Workspace entity registry"]
  pkg_apiproxy["apiproxy"]
  svc_sessionQuery["ctx.sessionQuery<br/>Session reads, traces, filters, and search"]
  pkg_session_reference["session-reference"]
  pkg_tool_session_query["tool-session-query"]
  svc_sessionReferences["ctx.sessionReferences<br/>Cross-session snapshot preparation"]
  pkg_tui["tui"]
  pkg_session_title["session-title"]
  svc_sessionTitle["ctx.sessionTitle<br/>Log-backed session titles"]
  pkg_session_title_first_message_llm["session-title-first-message-llm"]
  pkg_session_title_all_messages_llm["session-title-all-messages-llm"]
  pkg_system_prompt["system-prompt"]
  svc_systemPrompt["ctx.systemPrompt<br/>System prompt assembly registry"]
  pkg_tools["tools"]
  pkg_tool_fs["tool-fs"]
  pkg_tool_pty["tool-pty"]
  pkg_tool_web["tool-web"]
  svc_tools["ctx.tools<br/>Tool registry and guarded execution pipeline"]
  pkg_tool_ask_user["tool-ask-user"]
  pkg_tool_cordis["tool-cordis"]
  pkg_tool_skill["tool-skill"]
  pkg_tool_subagent["tool-subagent"]
  pkg_tool_todo["tool-todo"]
  pkg_user_interaction["user-interaction"]
  svc_userInteraction["ctx.userInteraction<br/>Human question/answer seam"]
  pkg_plan_mode["plan-mode"]
  svc_planMode["ctx.planMode<br/>Plan collaboration state"]
  pkg_commands["commands"]
  svc_commands["ctx.commands<br/>Human command registry"]
  svc_tui["ctx.tui<br/>Mounted-terminal interaction service"]
  pkg_skill["skill"]
  svc_skills["ctx.skills<br/>Skill provider registry"]
  pkg_skill_local["skill-local"]
  svc_agents["ctx.agents<br/>Agent service"]
  pkg_acp["acp"]
  pkg_tui_demo["tui-demo"]
  svc_agentLoop["ctx.agentLoop<br/>Concrete loop driver"]
  pkg_agent_spine_demo["agent-spine-demo"]
  pkg_goal["goal"]
  svc_goals["ctx.goals<br/>Same-session goal domain"]
  pkg_subprocess["subprocess"]
  svc_subprocess["ctx.subprocess<br/>Subprocess seam"]
  pkg_subprocess_local["subprocess-local"]
  pkg_bash_local["bash-local"]
  pkg_bash_sandbox["bash-sandbox"]
  pkg_lsp_local["lsp-local"]
  pkg_subagent_acp["subagent-acp"]
  pkg_bash["bash"]
  svc_bash["ctx.bash<br/>Bash executor seam"]
  svc_bashEnv["ctx.bashEnv<br/>Managed bash environment registry"]
  pkg_pty["pty"]
  svc_pty["ctx.pty<br/>Persistent PTY session registry"]
  pkg_pty_local["pty-local"]
  pkg_sandbox["sandbox"]
  svc_sandbox["ctx.sandbox<br/>Process-sandbox seam"]
  pkg_sandbox_local["sandbox-local"]
  pkg_sandbox_policy["sandbox-policy"]
  svc_sandboxPolicy["ctx.sandboxPolicy<br/>Sandbox policy home"]
  pkg_fs_sandbox["fs-sandbox"]
  pkg_approval["approval"]
  svc_approval["ctx.approval<br/>Approval seam"]
  pkg_permission["permission"]
  svc_permission["ctx.permission<br/>Permission presets"]
  pkg_code_runtime["code-runtime"]
  svc_codeRuntime["ctx.codeRuntime<br/>Code-execution seam"]
  pkg_code_runtime_worker["code-runtime-worker"]
  pkg_fs["fs"]
  svc_fs["ctx.fs<br/>Filesystem provider seam"]
  pkg_fs_local["fs-local"]
  pkg_fs_policy["fs-policy"]
  pkg_compact["compact"]
  svc_compact["ctx.compact<br/>Compaction seam"]
  pkg_subagent["subagent"]
  svc_subagents["ctx.subagents<br/>Subagent provider registry"]
  pkg_subagent_spawn["subagent-spawn"]
  pkg_subagent_fork["subagent-fork"]
  pkg_tool_ralph["tool-ralph"]
  pkg_tasks["tasks"]
  svc_tasks["ctx.tasks<br/>Background task registry"]
  pkg_tasks_local["tasks-local"]
  pkg_tool_tasks["tool-tasks"]
  pkg_web["web"]
  svc_web["ctx.web<br/>Web access provider registry"]
  pkg_web_search_exa["web-search-exa"]
  pkg_web_search_perplexity["web-search-perplexity"]
  pkg_web_search_deepseek["web-search-deepseek"]
  pkg_web_fetch_local["web-fetch-local"]
  pkg_spill["spill"]
  svc_spillStore["ctx.spillStore<br/>Spill storage seam"]
  pkg_spill_local["spill-local"]
  pkg_spill_policy["spill-policy"]
  pkg_webserver["webserver"]
  svc_httpServer["ctx.httpServer<br/>HTTP route registration"]
  pkg_connection["connection"]
  pkg_modules["modules"]
  pkg_hmr["hmr"]
  svc_clientModuleHost["ctx.clientModuleHost<br/>Client plugin graph host"]
  pkg_workflow["workflow"]
  svc_workflows["ctx.workflows<br/>Workflow script engine"]
  pkg_workflow_workerthread["workflow-workerthread"]
  pkg_tool_workflow["tool-workflow"]
  pkg_acp --> svc_approval
  pkg_agent --> svc_agents
  pkg_agent_loop --> svc_agentLoop
  pkg_approval --> svc_approval
  pkg_bash --> svc_bash
  pkg_bash_local --> svc_bash
  pkg_bash_sandbox --> svc_bash
  pkg_code_runtime --> svc_codeRuntime
  pkg_code_runtime_worker --> svc_codeRuntime
  pkg_commands --> svc_commands
  pkg_compact --> svc_compact
  pkg_compact_basic --> svc_compact
  pkg_compact_tool_result_prune --> svc_toolResultPrune
  pkg_fs --> svc_fs
  pkg_fs_local --> svc_fs
  pkg_fs_sandbox --> svc_fs
  pkg_goal --> svc_goals
  pkg_invariants --> svc_invariants
  pkg_llm --> svc_llm
  pkg_llm_deepseek --> svc_llm
  pkg_llm_pi_ai --> svc_llm
  pkg_llm_replay --> svc_llm
  pkg_modules --> svc_clientModuleHost
  pkg_permission --> svc_permission
  pkg_plan_mode --> svc_planMode
  pkg_pty --> svc_pty
  pkg_pty_local --> svc_pty
  pkg_sandbox --> svc_sandbox
  pkg_sandbox_local --> svc_sandbox
  pkg_sandbox_policy --> svc_sandboxPolicy
  pkg_session --> svc_sessions
  pkg_session_persistence --> svc_sessionPersistence
  pkg_session_persistence_jsonl --> svc_sessionPersistence
  pkg_session_persistence_sqlite --> svc_sessionPersistence
  pkg_session_query --> svc_sessionQuery
  pkg_session_query_sqlite --> svc_sessionQuery
  pkg_session_reference --> svc_sessionReferences
  pkg_session_title --> svc_sessionTitle
  pkg_session_title_all_messages_llm --> svc_sessionTitle
  pkg_session_title_first_message_llm --> svc_sessionTitle
  pkg_skill --> svc_skills
  pkg_skill_local --> svc_skills
  pkg_spill --> svc_spillStore
  pkg_spill_local --> svc_spillStore
  pkg_storage --> svc_storage
  pkg_storage_domain --> svc_storageDomain
  pkg_storage_json --> svc_storage
  pkg_storage_sqlite --> svc_storage
  pkg_subagent --> svc_subagents
  pkg_subagent_acp --> svc_subagents
  pkg_subagent_fork --> svc_subagents
  pkg_subagent_spawn --> svc_subagents
  pkg_subprocess --> svc_subprocess
  pkg_subprocess_local --> svc_subprocess
  pkg_system_prompt --> svc_systemPrompt
  pkg_tasks --> svc_tasks
  pkg_tasks_local --> svc_tasks
  pkg_token_meter --> svc_tokenMeter
  pkg_tool_bash --> svc_bashEnv
  pkg_tools --> svc_tools
  pkg_tui --> svc_tui
  pkg_tui --> svc_userInteraction
  pkg_user_interaction --> svc_userInteraction
  pkg_web --> svc_web
  pkg_web_fetch_local --> svc_web
  pkg_web_search_deepseek --> svc_web
  pkg_web_search_exa --> svc_web
  pkg_web_search_perplexity --> svc_web
  pkg_webserver --> svc_httpServer
  pkg_workflow --> svc_workflows
  pkg_workflow_workerthread --> svc_workflows
  pkg_workspace --> svc_workspace
  svc_agentLoop --> pkg_agent_spine_demo
  svc_agents --> pkg_acp
  svc_agents --> pkg_agent_loop
  svc_agents --> pkg_cli_demo
  svc_agents --> pkg_subagent_inprocess
  svc_agents --> pkg_tui_demo
  svc_approval --> pkg_tool_bash
  svc_approval --> pkg_tools
  svc_bash --> pkg_hooks_claude
  svc_bash --> pkg_hooks_codex
  svc_bash --> pkg_tool_bash
  svc_clientModuleHost --> pkg_hmr
  svc_codeRuntime --> pkg_tools
  svc_commands --> pkg_tui
  svc_compact --> pkg_compact_basic
  svc_fs --> pkg_tool_fs
  svc_httpServer --> pkg_connection
  svc_httpServer --> pkg_hmr
  svc_httpServer --> pkg_modules
  svc_invariants --> pkg_agent
  svc_invariants --> pkg_agent_loop
  svc_invariants --> pkg_scope
  svc_invariants --> pkg_session
  svc_llm --> pkg_agent_loop
  svc_llm --> pkg_compact_basic
  svc_pty --> pkg_tool_pty
  svc_sandbox --> pkg_bash_sandbox
  svc_sandbox --> pkg_pty_local
  svc_sandboxPolicy --> pkg_bash_sandbox
  svc_sandboxPolicy --> pkg_fs_sandbox
  svc_sandboxPolicy --> pkg_pty_local
  svc_sessionPersistence --> pkg_agent_loop
  svc_sessionPersistence --> pkg_hooks_claude
  svc_sessionPersistence --> pkg_hooks_codex
  svc_sessionPersistence --> pkg_session_query
  svc_sessionPersistence --> pkg_session_query_sqlite
  svc_sessionPersistence --> pkg_tool_bash
  svc_sessionQuery --> pkg_session_reference
  svc_sessionQuery --> pkg_tool_session_query
  svc_sessionReferences --> pkg_tui
  svc_sessions --> pkg_agent
  svc_sessions --> pkg_agent_loop
  svc_sessions --> pkg_cli_demo
  svc_sessions --> pkg_invariants
  svc_sessions --> pkg_session_persistence
  svc_sessions --> pkg_session_query
  svc_sessions --> pkg_session_query_sqlite
  svc_sessions --> pkg_subagent_inprocess
  svc_skills --> pkg_tool_skill
  svc_spillStore --> pkg_spill_policy
  svc_storage --> pkg_storage_domain
  svc_storageDomain --> pkg_workspace
  svc_subagents --> pkg_tool_ralph
  svc_subagents --> pkg_tool_subagent
  svc_subprocess --> pkg_bash_local
  svc_subprocess --> pkg_bash_sandbox
  svc_subprocess --> pkg_lsp_local
  svc_subprocess --> pkg_subagent_acp
  svc_systemPrompt --> pkg_agent_loop
  svc_systemPrompt --> pkg_tool_fs
  svc_systemPrompt --> pkg_tool_pty
  svc_systemPrompt --> pkg_tool_web
  svc_systemPrompt --> pkg_tools
  svc_tasks --> pkg_tool_bash
  svc_tasks --> pkg_tool_pty
  svc_tasks --> pkg_tool_subagent
  svc_tasks --> pkg_tool_tasks
  svc_tokenMeter --> pkg_compact_basic
  svc_toolResultPrune --> pkg_compact_basic
  svc_tools --> pkg_agent_loop
  svc_tools --> pkg_tool_ask_user
  svc_tools --> pkg_tool_bash
  svc_tools --> pkg_tool_cordis
  svc_tools --> pkg_tool_fs
  svc_tools --> pkg_tool_pty
  svc_tools --> pkg_tool_skill
  svc_tools --> pkg_tool_subagent
  svc_tools --> pkg_tool_todo
  svc_tools --> pkg_tool_web
  svc_userInteraction --> pkg_tool_ask_user
  svc_userInteraction --> pkg_tui
  svc_web --> pkg_tool_web
  svc_workflows --> pkg_tool_ralph
  svc_workflows --> pkg_tool_workflow
  svc_workspace --> pkg_apiproxy
  svc_fs -. event gate .-> pkg_fs_policy

ctx key	Role	Owner	Implementations	Direct consumers	Companion plugins	Note
ctx.llm	seam	llm	llm-deepseek, llm-pi-ai, llm-replay	agent-loop, compact-basic	-	Adapters register provider implementations; the loop and compaction call the provider-neutral stream service.
ctx.tokenMeter	core	token-meter	-	compact-basic	-	Owns isolated per-session replay folds; pressure consumers share immutable revisioned measurements.
ctx.toolResultPrune	core	compact-tool-result-prune	-	compact-basic	-	Rewrites oversized current tool results through replayable single-node surface replacements before summary compaction.
ctx.sessions	core	session	-	agent-loop, agent, cli-demo, session-persistence, session-query, session-query-sqlite, subagent-inprocess, invariants	-	Owns append-only Session instances and emits the durable session event feed.
ctx.invariants	core	invariants	-	session, agent, scope, agent-loop	-	Companion subpaths register owner-local checks; the service owns selection, uniqueness, child fibers, and package-attributed failures.
ctx.sessionPersistence	seam	session-persistence	session-persistence-jsonl, session-persistence-sqlite	agent-loop, tool-bash, hooks-claude, hooks-codex, session-query, session-query-sqlite	-	Backends persist the same SessionEvent vocabulary; apps choose a backend at composition time.
ctx.storage	seam	storage	storage-json, storage-sqlite	storage-domain	-	Backends register side by side under names; data forms (domain first) mount on the hub and translate typed operations into opaque KV-unit primitives.
ctx.storageDomain	core	storage-domain	-	workspace	-	Waits for every configured backend, then publishes the domain form as one lifecycle-bound service for typed durable state.
ctx.workspace	core	workspace	-	apiproxy	-	Owns WorkspaceId-branded records over the domain facility; stable sessionIds accounts drive Host RPC and GUI projections.
ctx.sessionQuery	seam	session-query	session-query-sqlite	session-reference, tool-session-query	-	The interface supplies exact reads, filters, and traces; its concrete backend adds full-text reconciliation, ranking, snippets, and cursor generations, while the model consumer owns workspace authority and cursor-free rendering.
ctx.sessionReferences	core	session-reference	-	tui	-	Projects bounded current-surface conversation snapshots into durable untrusted message context; host adapters own mention syntax.
ctx.sessionTitle	seam	session-title	session-title-first-message-llm, session-title-all-messages-llm	-	-	Owns the deterministic fallback, latest-title fold, and sole optional asynchronous provider registration.
ctx.systemPrompt	core	system-prompt	-	agent-loop, tools, tool-fs, tool-pty, tool-web	-	Collects prompt sections and model-facing tool schemas for each step.
ctx.tools	core	tools	-	agent-loop, tool-ask-user, tool-bash, tool-cordis, tool-fs, tool-pty, tool-skill, tool-subagent, tool-todo, tool-web	-	Registers capabilities, owns Code Mode transport, and routes calls through pre-policy, monotonic guards, around dispatch, post-policy, and final-result observation.
ctx.userInteraction	seam	user-interaction	tui	tool-ask-user, tui	-	UI front doors provide the active human-answer provider; tool-ask-user pauses a tool call on the provider-neutral ask() promise.
ctx.planMode	core	plan-mode	-	-	-	Folds logged plan/mode state, flushes user selections at turn boundaries, renders deployment-owned guidance, registers /plan, and keeps the plan-exit schema stable across transitions.
ctx.commands	core	commands	-	tui	-	Plugins register direct human commands; TUI consumes the effective per-agent catalog without sending invocations to the model.
ctx.tui	bundle	tui	-	-	-	One TUI front door provides a FIFO overlay host; injected plugins receive caller-fiber ownership without access to pi-tui or terminal lifecycle state.
ctx.skills	seam	skill	skill-local	tool-skill	-	Merges provider skill catalogs; tool-skill renders the session-prefix catalog and loads complete skill bodies.
ctx.agents	core	agent	-	agent-loop, acp, cli-demo, subagent-inprocess, tui-demo	-	Owns live Agent handles, the create/resume factory seam, and process-local initiator propagation.
ctx.agentLoop	bundle	agent-loop	-	agent-spine-demo	-	The one concrete loop plugin; extension packages depend on dsh-agent events and services, not on this package.
ctx.goals	core	goal	-	-	-	Folds revisioned objective state from the session log and keeps live continuation activation process-local.
ctx.subprocess	seam	subprocess	subprocess-local	bash-local, bash-sandbox, lsp-local, subagent-acp	-	The bash executors, the LSP host, and the ACP subagent backend spawn their children through ctx.subprocess; the service owns tree lifetime, stdio dispositions (pipes, inherit, bounded spill-backed collection), and kill escalation.
ctx.bash	seam	bash	bash-local, bash-sandbox	tool-bash, hooks-claude, hooks-codex	-	The model-facing bash tools and hook bridges consume this seam; sandboxed or remote executors replace bash-local without touching them.
ctx.bashEnv	core	tool-bash	-	-	-	Plugins declare effect-scoped DSH_* facts; tool-bash collects one trusted snapshot per execution and the executor rebuilds the namespace.
ctx.pty	seam	pty	pty-local	tool-pty	-	The registry owns exact-Agent session identity and cleanup; backends own terminal mechanics, while tool-pty exposes the owner-scoped model surface.
ctx.sandbox	seam	sandbox	sandbox-local	bash-sandbox, pty-local	-	Consumers hand over the exact argv they are about to spawn; same-world backends wrap it under a per-call policy and report enforcement.
ctx.sandboxPolicy	core	sandbox-policy	-	bash-sandbox, fs-sandbox, pty-local	-	The one home for the deployment default mode + workspace root; only the sandboxed executor and provider read the service (the tool layers use the pure sandbox/mode fold it also exports). Both enforcing families read it so bash and fs cannot confine to different roots.
ctx.approval	seam	approval	acp	tools, tool-bash	-	One-shot permission decisions dispatched over the approval/request waterfall; answerers are listeners (the ACP bridge for its own agents), absence fails closed to unavailable.
ctx.permission	core	permission	-	-	-	User-facing preset table (workspace-write/danger-full-access) bundling the sandbox-mode and approval-policy knobs; a switch writes one permission/preset event through to both knob events.
ctx.codeRuntime	seam	code-runtime	code-runtime-worker	tools	-	Runs one model-written program against host-provided async bindings; backends differ by substrate and language (the tool registry consumes it for Code Mode).
ctx.fs	seam	fs	fs-local, fs-sandbox	tool-fs	fs-policy	tool-fs executes read/write/edit through ctx.fs; fs-sandbox fences mutations by the shared sandbox mode; fs-policy contributes observed-state checks through the fs/* event gate.
ctx.compact	seam	compact	compact-basic	compact-basic	-	The basic backend consumes post-step pressure and request-error recovery events; a model-facing compact tool remains deferred.
ctx.subagents	seam	subagent	subagent-spawn, subagent-fork, subagent-acp	tool-subagent, tool-ralph	-	Providers implement transports; tool-subagent exposes configured delegation while tool-ralph requires one fresh structured-output route.
ctx.tasks	seam	tasks	tasks-local	tool-bash, tool-pty, tool-subagent, tool-tasks	-	Producers (background bash, PTY sends, and subagent delegations) register running work; tool-tasks is the model-facing control surface that reads, lists, and kills it; tasks-local is the process-local registry.
ctx.web	seam	web	web-search-exa, web-search-perplexity, web-search-deepseek, web-fetch-local	tool-web	-	Search and fetch providers register into one ctx.web seam; tool-web owns the stable model-facing names.
ctx.spillStore	seam	spill	spill-local	spill-policy	-	The backend saves oversized tool text and returns a model-facing locator plus retrieval hint; spill-policy is the tools/post-execute consumer that decides when to spill.
ctx.httpServer	core	webserver	-	connection, modules, hmr	-	Plain node:http carrier: named-route registry, index transform taps, and the static dist fallback; web-transport plugins register their own routes.
ctx.clientModuleHost	core	modules	-	hmr	-	Composes the DSH_BOOT entry graph from an incremental dshClient scan, serves plugin bundles, and notifies rebuilt/graph-changed subscribers.
ctx.workflows	seam	workflow	workflow-workerthread	tool-workflow, tool-ralph	-	One engine per context (bash shape, no named-provider registry); the general workflow and fixed Ralph consumers start runs whose agent() calls fan out through ctx.subagents.

Maintenance mode: hybrid: services are discovered from Cordis declarations; interface/implementation/consumer roles are classified in scripts/gen-doc-graphs.ts with a completeness guard.