simplify(seams): prune dead methods from the persistence and bash seams

Two capability seams carried abstract methods no production consumer calls.
A method no consumer programs against is not a seam — it is speculative
surface every implementation must still provide and test.

- SessionPersistence: remove has() and delete(), the coordinator's
  has/delete/deleteCore, and the PersistenceBackend.deleteStored hook (with its
  jsonl + sqlite + in-spec memory-stub impls). Surviving service surface:
  create/append/load/list. Production uses only load() (resume) and list()
  (ACP session/list).
- BashExecutor: remove get(id) and list(), the abstract decls and the
  LocalBashExecutor impls. The internal tasks map survives (it backs
  ownerOf/readOutput/kill); get/list were pure public accessors over it with no
  shipping caller and no bash_list tool.
- Migrate tests that reached through ctx.bash.get(id) to the public completion
  seam: a doneFor(id) helper over onTaskDone awaits a task by id, and the
  HMR-reload ownership test now proves task survival through A's own bash_output
  ([status: running]) plus ownerOf + B-rejection — a stronger through-the-tool
  assertion than the removed lookup peek.
- Update seam READMEs (six -> four service methods, drop the deleteStored hook
  and the get/list row) and the two implemented persistence RFCs in place.

Implements docs/rfc/implemented/simplification/2026-06-20-prune-dead-seam-methods.md

docs/cordis-catalog/events-and-services.md

@@ -327,9 +327,7 @@ Semantics every implementation must honor:
 abstract resolve(request: BashExecRequest): BashExecSpec
 abstract run(spec: BashExecSpec): Promise<BashRunResult>
 abstract start(spec: BashExecSpec): BashTask
-abstract get(id: string): BashTask | undefined
 abstract ownerOf(id: string): string | undefined
-abstract list(): BashTask[]
 abstract readOutput(id: string): BashTaskRead
 abstract kill(id: string): boolean
 onTaskDone(listener: BashTaskListener): () => void
@@ -369,8 +367,6 @@ abstract create(meta: SessionHeader): Promise<void>
 abstract append(id: SessionId, events: readonly SessionEvent[]): Promise<void>
 abstract load(id: SessionId): Promise<{ meta: SessionHeader; events: SessionEvent[] }>
 abstract list(): Promise<SessionHeader[]>
-abstract has(id: SessionId): Promise<boolean>
-abstract delete(id: SessionId): Promise<void>
 ```
 
 Types: [SessionEvent](../core-data-structures/core.md)

docs/rfc/README.md

@@ -52,7 +52,6 @@ Do NOT write one for a mechanical or local choice (a variable name, a one-file r
 | [Unify the agent id and the session id](proposed/simplification/2026-06-20-unify-agent-and-session-id.md) | 2026-06-20 |
 | [Stop mirroring durable boundaries as agent events](proposed/simplification/2026-06-20-remove-agent-boundary-mirror-events.md) | 2026-06-20 |
 | [Keep one public stop primitive](proposed/simplification/2026-06-20-public-agent-stop-surface.md) | 2026-06-20 |
-| [Prune dead methods from the persistence and bash seams](proposed/simplification/2026-06-20-prune-dead-seam-methods.md) | 2026-06-20 |
 | [Fold trace-only session facts into load-bearing events](proposed/simplification/2026-06-20-collapse-trace-only-session-events.md) | 2026-06-20 |
 
 ### Architecture
@@ -96,6 +95,7 @@ Do NOT write one for a mechanical or local choice (a variable name, a one-file r
 | [Drop the mutable session summary](implemented/simplification/2026-06-19-drop-mutable-session-summary.md) | 2026-06-19 |
 | [Drop unconsumed assembled LLM convenience surfaces](implemented/simplification/2026-06-20-drop-unconsumed-llm-assembled-surfaces.md) | 2026-06-20 |
 | [Drop the unconsumed `llm/adapter-change` event](implemented/simplification/2026-06-20-drop-unconsumed-llm-adapter-change-event.md) | 2026-06-20 |
+| [Prune dead methods from the persistence and bash seams](implemented/simplification/2026-06-20-prune-dead-seam-methods.md) | 2026-06-20 |
 
 ### Architecture
 

docs/rfc/implemented/architecture/2026-06-14-session-persistence.md

@@ -16,7 +16,7 @@ The [event-sourced model](2026-06-11-event-sourced-sessions.md) makes the append
 
 Persistence is an abstract **capability seam** ([capability seams](2026-06-13-capability-seams.md), the `dsh-bash` template), not loop or core logic:
 
-1. **Interface** (`dsh-session-persistence`, `ctx.sessionPersistence`) — an abstract `SessionPersistence` service: `create`/`append`/`load`/`list`/`has`/`delete`. Its persisted unit IS the existing `SessionEvent` (`{ type, seq, time, data }`), reused verbatim — no conversion type.
+1. **Interface** (`dsh-session-persistence`, `ctx.sessionPersistence`) — an abstract `SessionPersistence` service: `create`/`append`/`load`/`list`. Its persisted unit IS the existing `SessionEvent` (`{ type, seq, time, data }`), reused verbatim — no conversion type.
 2. **Implementation** (`dsh-session-persistence-jsonl`) — an append-only JSONL log per session (a `SessionHeader` line then one `SessionEvent` per line, verbatim **including `assistant/chunk`**).
 
 Key choices recorded here because they are durable, contested, and surprising:

docs/rfc/implemented/architecture/2026-06-18-shared-persistence-write-coordinator.md

@@ -4,24 +4,24 @@ Status: implemented (proposed and accepted 2026-06-18, implemented 2026-06-20)
 
 ## Problem
 
-`dsh-session-persistence-jsonl` and `dsh-session-persistence-sqlite` intentionally prove the same `SessionPersistence` contract over different storage media, but their write-path orchestration was duplicated: per-session state, `session/created` adoption, backend-specific prefix reads, write-behind buffers, serialized flush chains, HMR seeding, and dispose drains. The pure seed-prefix collision and serializability guards had already moved into the seam package; the remaining orchestration was still correctness-heavy and received the same fixes twice. A code-level diff showed the two backends were byte-identical — or same-algorithm — for ALL of it: the four maps (`states`/`buffers`/`chains`/`inits`), `installWritePath`, `initFor`, `onCreated`'s four cases, `flush`, `drain`, `serialize`, `adopt`, `adoptLivePrefix`, `assertVersion`, and the `create`/`append`/`load`/`has`/`delete` skeletons. Only the storage primitives (write bytes vs. INSERT rows) differed.
+`dsh-session-persistence-jsonl` and `dsh-session-persistence-sqlite` intentionally prove the same `SessionPersistence` contract over different storage media, but their write-path orchestration was duplicated: per-session state, `session/created` adoption, backend-specific prefix reads, write-behind buffers, serialized flush chains, HMR seeding, and dispose drains. The pure seed-prefix collision and serializability guards had already moved into the seam package; the remaining orchestration was still correctness-heavy and received the same fixes twice. A code-level diff showed the two backends were byte-identical — or same-algorithm — for ALL of it: the four maps (`states`/`buffers`/`chains`/`inits`), `installWritePath`, `initFor`, `onCreated`'s four cases, `flush`, `drain`, `serialize`, `adopt`, `adoptLivePrefix`, `assertVersion`, and the `create`/`append`/`load` skeletons. Only the storage primitives (write bytes vs. INSERT rows) differed.
 
 ## Decision
 
-Extract a backend-agnostic `PersistenceCoordinator` into `dsh-session-persistence`. The coordinator owns the orchestration once; each first-party backend composes one (`new PersistenceCoordinator(ctx, this)`), implements a small `PersistenceBackend` hook interface, and delegates its six public service methods (`create`/`append`/`load`/`list`/`has`/`delete`) to it.
+Extract a backend-agnostic `PersistenceCoordinator` into `dsh-session-persistence`. The coordinator owns the orchestration once; each first-party backend composes one (`new PersistenceCoordinator(ctx, this)`), implements a small `PersistenceBackend` hook interface, and delegates its four public service methods (`create`/`append`/`load`/`list`) to it.
 
 Composition, not inheritance. The coordinator is a concrete class the backend holds, not a base class the backend extends. The RFC's risk — "a coordinator must not make unusual backends fight an inheritance hierarchy" — is avoided: a backend exposes only the hooks; it cannot reach the coordinator's private orchestration state, and the public `SessionPersistence` service shape is unchanged, so a third-party backend MAY still implement the abstract service directly without the coordinator at all.
 
 ### The hook interface (`PersistenceBackend<TornMarker>`)
 
-Seven methods (six required + an optional lifecycle hook) — the only seam between the coordinator and storage:
+Six methods (five required + an optional lifecycle hook) — the only seam between the coordinator and storage:
 
 - `name` — backend label for the dispose-failure `AggregateError`.
-- `loadStored(id)` — read a stored prefix by id, scanning ANY storage scope (every JSONL cwd bucket; SQLite's id is globally unique). Used by resume/load and, via `!== undefined`, the create-collision probe and `has`.
+- `loadStored(id)` — read a stored prefix by id, scanning ANY storage scope (every JSONL cwd bucket; SQLite's id is globally unique). Used by resume/load and, via `!== undefined`, the create-collision probe.
 - `loadLive(id, cwd)` — read a stored prefix SCOPED to `cwd`. **Deliberately distinct from `loadStored`**: HMR live-adoption must only adopt a persisted log at the SAME cwd as the live session; a same-id log at a different cwd is a collision, not a resume. Collapsing the two reintroduces a cross-cwd adoption bug. SQLite ignores `cwd`.
 - `appendBatch(meta, events, isMaterialized)` — durably append a contiguous batch, lazily materializing the session ATOMICALLY when not yet materialized (the materialize-write and the first event batch must commit together — a crash between them must not leave a materialized-but-empty session; this is why there is no separate `materialize` hook).
 - `commitRepair(meta, tornMarker, closers)` — make a crash repair durable: truncate the torn tail (iff `tornMarker !== undefined`) and append `closers`. **NOT required to be atomic** — JSONL legitimately truncates-then-appends in two fsync'd steps, SQLite does DELETE+INSERT in one transaction. Used by `load` (truncate + synthetic closers) and live-adoption (truncate only, `closers = []`).
-- `deleteStored(id)` / `list()` — remove a stored artifact / list all stored metadata.
+- `list()` — list all stored metadata.
 - `close?()` — optional lifecycle teardown (SQLite closes its db handle; JSONL omits it), awaited in the dispose effect AFTER the quiescence drain so a close failure never masks a drain error.
 
 ### The opaque torn marker
@@ -34,4 +34,4 @@ The shared `runPersistenceContract` (public-API contract) keeps running for ever
 
 ## Risks and what we gave up
 
-The pre-extraction duplication was verbose but explicit — each backend read top-to-bottom. The coordinator adds one indirection (the hook seam) and one new concept (the opaque torn marker). This clears the bar because the centralized logic is the correctness-heavy part that was already being fixed twice, and the hook set is narrow (seven methods, no inheritance). The hook surface was deliberately held to the minimum: `has` and the create-collision probe are NOT separate hooks — they fold into `loadStored(id) !== undefined`; there is no separate `materialize` hook (folded into `appendBatch` for atomicity); `list()` stays a backend method with no coordinator pass-through (listing needs none of the orchestration). The net effect is a reduction: one orchestration copy instead of two, the backends shrank by ~1200 lines of duplicated churn, and a future backend implements ~7 small primitives instead of copying the entire `session/event` → buffer → flush machinery.
+The pre-extraction duplication was verbose but explicit — each backend read top-to-bottom. The coordinator adds one indirection (the hook seam) and one new concept (the opaque torn marker). This clears the bar because the centralized logic is the correctness-heavy part that was already being fixed twice, and the hook set is narrow (six methods, no inheritance). The hook surface was deliberately held to the minimum: the create-collision probe is NOT a separate hook — it folds into `loadStored(id) !== undefined`; there is no separate `materialize` hook (folded into `appendBatch` for atomicity); `list()` stays a backend method with no coordinator pass-through (listing needs none of the orchestration). The net effect is a reduction: one orchestration copy instead of two, the backends shrank by ~1200 lines of duplicated churn, and a future backend implements a handful of small primitives instead of copying the entire `session/event` → buffer → flush machinery.

docs/rfc/proposed/simplification/2026-06-20-prune-dead-seam-methods.md → docs/rfc/implemented/simplification/2026-06-20-prune-dead-seam-methods.md

@@ -1,6 +1,6 @@
 # RFC: Prune dead methods from the persistence and bash capability seams
 
-Status: proposed
+Status: implemented (proposed and accepted 2026-06-20)
 
 ## Problem
 

packages/bash/bash-local/src/index.ts

@@ -176,20 +176,12 @@ export class LocalBashExecutor extends BashExecutor {
     return task
   }
 
-  get(id: string): BashTask | undefined {
-    return this.tasks.get(id)
-  }
-
   ownerOf(id: string): string | undefined {
     // Unknown id and known-but-ownerless both read as undefined — the consumer
     // treats undefined as "open" and a truly unknown id fails at readOutput/kill.
     return this.tasks.get(id)?.owner
   }
 
-  list(): BashTask[] {
-    return [...this.tasks.values()]
-  }
-
   readOutput(id: string): BashTaskRead {
     const task = this.tasks.get(id)
     if (!task) throw new Error(`unknown bash task "${id}"`)

packages/bash/bash-local/tests/executor.spec.ts

@@ -98,8 +98,6 @@ describe('LocalBashExecutor background tasks', () => {
     const task = bash.start(bash.resolve({ command: 'sleep 0.2; echo done' }))
     expect(Date.now() - before).toBeLessThan(150)
     expect(task.status).toBe('running')
-    expect(bash.get(task.id)).toBe(task)
-    expect(bash.list()).toContain(task)
     await task.done
     expect(task.status).toBe('completed')
     expect(task.exitCode).toBe(0)
@@ -237,7 +235,6 @@ describe('LocalBashExecutor background tasks', () => {
     await running.done
     expect(finished.status).toBe('completed')
     expect(running.signal).toBe('SIGTERM')
-    expect(bash.list()).toEqual([])
   })
 
   it('disposing the executor fiber kills running tasks (no orphans)', async () => {
@@ -249,14 +246,13 @@ describe('LocalBashExecutor background tasks', () => {
     bash.onTaskDone(listener)
 
     const task = bash.start(bash.resolve({ command: 'sleep 60' }))
-    const running = bash.get(task.id)!
+    const running = task
     await new Promise(resolve => setTimeout(resolve, 50))
 
     // Grab the pid before dispose clears the registry.
     const pid = (running as unknown as { running: { pid: number } }).running.pid
     await fiber.dispose()
     await waitGone(pid)
-    expect(bash.list()).toEqual([])
     // Listener silenced by base-class teardown — no late notifications.
     expect(listener).not.toHaveBeenCalled()
   })

packages/bash/bash/README.md

@@ -18,7 +18,6 @@ The split mirrors the LLM seam (`LlmService`/`LlmAdapter`) and the agent-tool su
 |---|---|
 | `run(spec)` | Foreground execution. Resolves when the command finishes. **Rejects only for infrastructure failures** (unusable workdir, missing shell, pre-aborted signal); nonzero exits, timeout kills, and abort kills resolve with a descriptive `BashRunResult`. |
 | `start(spec)` | Background execution. Returns a `BashTask` handle immediately; **no timeout applies** (stop tasks via `kill`). |
-| `get(id)` / `list()` | Task lookup. |
 | `ownerOf(id)` | The opaque OWNER token recorded for a background task at `start` (from the spec's `owner`), or `undefined` for an unknown id OR a known-but-ownerless task. The executor stores/returns it verbatim and NEVER interprets it — the access POLICY lives in the consumer (`dsh-tool-bash`), which compares `ownerOf(id)` to the caller's token. Storing ownership here (disposed with the executor's fiber) is what makes it survive a consumer HMR reload. |
 | `readOutput(id)` | **Incremental** output read — consecutive reads never re-deliver. Reads that lost data to buffer bounds flag `lossy` and point at full-stream spill files. Throws for unknown ids. |
 | `kill(id)` | Kill a running task. Returns `false` when it already finished; throws for unknown ids. |

packages/bash/bash/src/index.ts

@@ -85,9 +85,6 @@ export abstract class BashExecutor extends Service {
   /** Start a background task and return its handle immediately. */
   abstract start(spec: BashExecSpec): BashTask
 
-  /** Look up a background task by id. */
-  abstract get(id: string): BashTask | undefined
-
   /**
    * The opaque OWNER token recorded for a background task at {@link start}
    * (from the {@link BashExecSpec}'s `owner`), or `undefined` for an unknown id
@@ -103,9 +100,6 @@ export abstract class BashExecutor extends Service {
    */
   abstract ownerOf(id: string): string | undefined
 
-  /** All tracked background tasks (insertion order). */
-  abstract list(): BashTask[]
-
   /** Read output produced since the previous read. Throws for unknown ids. */
   abstract readOutput(id: string): BashTaskRead
 

packages/bash/bash/tests/service.spec.ts

@@ -44,18 +44,10 @@ class StubExecutor extends BashExecutor {
     return task
   }
 
-  get(id: string): BashTask | undefined {
-    return this.tasks.get(id)
-  }
-
   ownerOf(id: string): string | undefined {
     return this.owners.get(id)
   }
 
-  list(): BashTask[] {
-    return [...this.tasks.values()]
-  }
-
   readOutput(id: string): BashTaskRead {
     const task = this.tasks.get(id)
     if (!task) throw new Error(`unknown bash task "${id}"`)
@@ -88,8 +80,6 @@ describe('BashExecutor service seam', () => {
   it('registers as ctx.bash and serves the abstract API', async () => {
     const { bash } = await setup()
     const task = bash.start(bash.resolve({ command: 'sleep 1' }))
-    expect(bash.get(task.id)).toBe(task)
-    expect(bash.list()).toEqual([task])
     expect(bash.kill(task.id)).toBe(true)
     expect(bash.kill(task.id)).toBe(false)
     const result = await bash.run(bash.resolve({ command: 'true' }))

packages/bash/tool-bash/tests/integration.spec.ts

@@ -8,6 +8,7 @@ import ToolRegistry from '@deepseek-ai/dsh-tools'
 import AgentRegistry from '@deepseek-ai/dsh-agent'
 import AgentLoop, { ReactLoopAgent } from '@deepseek-ai/dsh-agent-loop'
 import { LocalBashExecutor } from '@deepseek-ai/dsh-bash-local'
+import type { BashTask } from '@deepseek-ai/dsh-bash'
 import * as ToolBash from '@deepseek-ai/dsh-tool-bash'
 import { MockAdapter, textResponse, toolCallResponse } from '../../../core/agent-loop/tests/mock-adapter.ts'
 
@@ -143,13 +144,18 @@ describe('bash tool through the agent loop', () => {
       return next()
     })
 
+    // Capture the single background task's completion. Registered BEFORE send so
+    // a fast task (echo) can't finish before the listener is attached; onTaskDone
+    // delivers the task object once it completes (completion may race turn end).
+    const taskDone = new Promise<BashTask>((resolve) => {
+      const dispose = ctx.bash.onTaskDone((task) => { dispose(); resolve(task) })
+    })
+
     agent.send([{ type: 'text', text: 'run echo bg-ok in the background' }])
     await waitForIdle(ctx, agent)
 
     // Wait for the background task itself (completion may race turn end).
-    const task = ctx.bash.get(taskId)
-    if (!task) throw new Error(`task ${taskId} not registered`)
-    await task.done
+    await taskDone
 
     const log = events(agent)
     const firstResult = findEvent(log, 'tool/result')

packages/bash/tool-bash/tests/tools.spec.ts

@@ -66,6 +66,23 @@ function text(result: { content: { type: string; text?: string }[] }): string {
   return result.content.filter(block => block.type === 'text').map(block => block.text).join('')
 }
 
+/**
+ * Resolve once the background task with `id` completes. The task is started
+ * indirectly (via `ctx.tools.execute`), so `start()`'s return is not accessible
+ * here; the executor's `onTaskDone` listener delivers the SAME task object on
+ * completion, which is the surviving seam for awaiting a task by id.
+ */
+function doneFor(ctx: Context, id: string): Promise<BashTask> {
+  return new Promise<BashTask>((resolve) => {
+    const dispose = ctx.bash.onTaskDone((task) => {
+      if (task.id === id) {
+        dispose()
+        resolve(task)
+      }
+    })
+  })
+}
+
 class LossyReadBashExecutor extends BashExecutor {
   private readonly task: BashTask = {
     id: 'bash-lossy',
@@ -94,18 +111,10 @@ class LossyReadBashExecutor extends BashExecutor {
     return this.task
   }
 
-  get(id: string): BashTask | undefined {
-    return id === this.task.id ? this.task : undefined
-  }
-
   ownerOf(): string | undefined {
     return undefined
   }
 
-  list(): BashTask[] {
-    return [this.task]
-  }
-
   readOutput(id: string): BashTaskRead {
     if (id !== this.task.id) throw new Error(`unknown bash task "${id}"`)
     return { task: this.task, delta: 'tail', lossy: true }
@@ -286,7 +295,7 @@ describe('background tools', () => {
     expect(text(first)).toContain('first')
     expect(text(first)).toContain('[status: running]')
 
-    await ctx.bash.get(id)!.done
+    await doneFor(ctx, id)
     const second = await call(ctx, 'bash_output', { task_id: id })
     expect(text(second)).toContain('second')
     expect(text(second)).not.toContain('first')
@@ -306,7 +315,7 @@ describe('background tools', () => {
 
     const started = await call(ctx, 'bash', { command: 'for i in $(seq 1 200); do printf "line-%04d\\n" $i; done', description: 'test command', run_in_background: true })
     const id = /task (bash-\d+)/.exec(text(started))![1]!
-    await ctx.bash.get(id)!.done
+    await doneFor(ctx, id)
     const read = await call(ctx, 'bash_output', { task_id: id })
     expect(text(read)).toContain('[some output was dropped from memory; full output: ')
   })
@@ -329,7 +338,7 @@ describe('background tools', () => {
 
     const killed = await call(ctx, 'bash_kill', { task_id: id })
     expect(text(killed)).toBe(`killed background task ${id}`)
-    await ctx.bash.get(id)!.done
+    await doneFor(ctx, id)
 
     const again = await call(ctx, 'bash_kill', { task_id: id })
     expect(text(again)).toBe(`task ${id} had already finished`)
@@ -373,7 +382,7 @@ describe('background tools', () => {
       agent,
     })
     const id = /task (bash-\d+)/.exec(text(started))![1]!
-    await ctx.bash.get(id)!.done
+    await doneFor(ctx, id)
 
     expect(inject).toHaveBeenCalledTimes(1)
     const [content, options] = inject.mock.calls[0] as [
@@ -396,7 +405,7 @@ describe('background tools', () => {
       agent,
     })
     const id = /task (bash-\d+)/.exec(text(started))![1]!
-    await expect(ctx.bash.get(id)!.done).resolves.toBeUndefined()
+    await expect(doneFor(ctx, id)).resolves.toBeDefined()
   })
 
   it('rethrows a non-disposed inject failure (not blindly swallowed)', async () => {
@@ -415,7 +424,7 @@ describe('background tools', () => {
         agent,
       })
       const id = /task (bash-\d+)/.exec(text(started))![1]!
-      await ctx.bash.get(id)!.done
+      await doneFor(ctx, id)
       // notifyTaskDone caught and logged the rethrown error.
       expect(errorSpy).toHaveBeenCalled()
       const logged = errorSpy.mock.calls.flat().some(arg => arg instanceof Error && arg.message === 'unexpected inject bug')
@@ -443,7 +452,7 @@ describe('background tools', () => {
     const id = /task (bash-\d+)/.exec(text(started))![1]!
     // Unregister the agent BEFORE the task completes (simulate disconnect).
     unregisterFakeAgents(ctx)
-    await expect(ctx.bash.get(id)!.done).resolves.toBeUndefined()
+    await expect(doneFor(ctx, id)).resolves.toBeDefined()
     expect(inject).not.toHaveBeenCalled()
   })
 
@@ -451,7 +460,7 @@ describe('background tools', () => {
     const ctx = await setup()
     const started = await call(ctx, 'bash', { command: 'true', description: 'test command', run_in_background: true })
     const id = /task (bash-\d+)/.exec(text(started))![1]!
-    await expect(ctx.bash.get(id)!.done).resolves.toBeUndefined()
+    await expect(doneFor(ctx, id)).resolves.toBeDefined()
   })
 })
 
@@ -534,7 +543,7 @@ describe('background task ownership (cross-session isolation)', () => {
     const b = fakeAgent('sess-b')
     const started = await callAs(ctx, a, 'bash', { command: 'echo done', description: 'bg', run_in_background: true })
     const id = /task (bash-\d+)/.exec(text(started))![1]!
-    await ctx.bash.get(id)!.done
+    await doneFor(ctx, id)
     // Completion does NOT clear ownership: B is still rejected, A still allowed.
     const readByB = await callAs(ctx, b, 'bash_output', { task_id: id })
     expect(readByB.isError).toBe(true)
@@ -567,7 +576,9 @@ describe('background task ownership (cross-session isolation)', () => {
     // token) survive.
     await fiber.dispose()
     await ctx.plugin(ToolBash)
-    expect(ctx.bash.get(id)?.status).toBe('running')
+    // The task survived the reload, still running and still owned by A — proven
+    // via A's own bash_output (reports running status) and the surviving owner token.
+    expect(text(await callAs(ctx, a, 'bash_output', { task_id: id }))).toContain('[status: running]')
     expect(ctx.bash.ownerOf(id)).toBe('sess-a')
 
     // After reload, ownership is INTACT → B is STILL rejected.
@@ -675,10 +686,10 @@ describe('status lines', () => {
     const ctx = await setup()
     const started = await call(ctx, 'bash', { command: 'sleep 60', description: 'test command', run_in_background: true })
     const id = /task (bash-\d+)/.exec(text(started))![1]!
-    const task = ctx.bash.get(id)!
+    const done = doneFor(ctx, id)
 
     await call(ctx, 'bash_kill', { task_id: id })
-    await task.done
+    const task = await done
     // Simulate the variant where the close event carried no signal.
     task.signal = null
     const read = await call(ctx, 'bash_output', { task_id: id })
@@ -689,8 +700,7 @@ describe('status lines', () => {
     const ctx = await setup()
     const started = await call(ctx, 'bash', { command: 'true', description: 'test command', run_in_background: true })
     const id = /task (bash-\d+)/.exec(text(started))![1]!
-    const task = ctx.bash.get(id)!
-    await task.done
+    const task = await doneFor(ctx, id)
     // Defensive: completed tasks always carry an exit code in practice; the
     // ?? 0 fallback covers task shapes from other executor implementations.
     task.exitCode = null

packages/session-persistence/session-persistence-jsonl/README.md

@@ -21,7 +21,7 @@ The JSONL durable session-persistence backend — a concrete `SessionPersistence
 
 ## Durability and crash semantics
 
-- **Lazy materialization.** `create(meta)` writes nothing; the `.jsonl` (header + first batch) is written atomically (temp-write + `fsync` + rename) on the first `append`. A created-but-never-appended session leaves nothing on disk and is absent from `has`/`list`.
+- **Lazy materialization.** `create(meta)` writes nothing; the `.jsonl` (header + first batch) is written atomically (temp-write + `fsync` + rename) on the first `append`. A created-but-never-appended session leaves nothing on disk and is absent from `list`.
 - **Append-only.** Committed events (at or below a flushed `turn/end`) are never rewritten. Subsequent appends are line appends at EOF + `fsync`.
 - **Crash recovery — close, don't truncate.** A crash can leave a log whose final turn never closed (real events after the last `turn/end`). `load` PRESERVES those events (a turn can be huge — they are real work) and closes the orphaned turn by durably appending synthetic boundary events: an error `tool/result` for every `tool-call` the crash left unanswered (the loop logs the assistant message before running the tools, so a mid-tool crash leaves dangling calls — and `deriveMessages()` would replay an assistant tool-call with no result, which providers reject), then a `step/end` if a step was open, then `turn/end {kind:'interrupted'}`, returning a balanced log. Only a never-fully-written **torn tail fragment** (a final line with no newline / unparseable) is `ftruncate`d away before the closers are written. See [session persistence](../../../docs/rfc/implemented/architecture/2026-06-14-session-persistence.md).
 - **Contiguous-seq.** `load` rejects a mid-log parse error or `seq` gap (unloadable); `append` rejects a batch whose first `seq` does not continue the stored log, and rejects non-JSON-serializable `event.data` naming the offending event type.

packages/session-persistence/session-persistence-jsonl/src/index.ts

@@ -11,7 +11,7 @@
  * (the `session/event` → buffer → `session/flush` drain, per-session
  * serialization, write cursors, fork-seed persistence, HMR live-adoption,
  * crash-repair sequencing, dispose quiescence) lives in the backend-agnostic
- * {@link PersistenceCoordinator} this class composes. The six public
+ * {@link PersistenceCoordinator} this class composes. The four public
  * {@link SessionPersistence} methods delegate to the coordinator.
  *
  * @module @deepseek-ai/dsh-session-persistence-jsonl
@@ -101,14 +101,6 @@ export class SessionPersistenceJsonl extends SessionPersistence implements Persi
     return this.coordinator.load(id)
   }
 
-  has(id: SessionId): Promise<boolean> {
-    return this.coordinator.has(id)
-  }
-
-  delete(id: SessionId): Promise<void> {
-    return this.coordinator.delete(id)
-  }
-
   // `list` is BOTH the public service method and the PersistenceBackend hook —
   // one method, the bucket walk below. The coordinator adds no orchestration for
   // listing (no per-id serialization, no cursor), so it would just call back into
@@ -180,12 +172,6 @@ export class SessionPersistenceJsonl extends SessionPersistence implements Persi
     if (closers.length > 0) await this.appendLines(meta, closers)
   }
 
-  /** Remove a session's log file (the coordinator clears its in-memory state). */
-  async deleteStored(id: SessionId): Promise<void> {
-    const file = await this.findLog(id)
-    if (file) await rm(file.path, { force: true })
-  }
-
   /** List all stored sessions' metadata (header line only — no full-log parse). */
   async list(): Promise<SessionHeader[]> {
     const metas: SessionHeader[] = []
@@ -341,9 +327,9 @@ export class SessionPersistenceJsonl extends SessionPersistence implements Persi
 
   /**
    * Find a session's log file by id across ALL cwd buckets — the any-cwd scan
-   * for `loadStored`/`deleteStored` (resume and removal identify a session by id
-   * alone). The cwd-scoped lookup (`loadLive`) does NOT use this; it goes
-   * straight to `logPath(cwd)` so a no-cwd session can't match a real-cwd bucket.
+   * for `loadStored` (resume identifies a session by id alone). The cwd-scoped
+   * lookup (`loadLive`) does NOT use this; it goes straight to `logPath(cwd)` so
+   * a no-cwd session can't match a real-cwd bucket.
    */
   private async findLog(id: SessionId): Promise<{ path: string; cwd: string | undefined } | undefined> {
     const target = encodeSegment(id) + '.jsonl'

packages/session-persistence/session-persistence-jsonl/tests/jsonl.spec.ts

@@ -105,12 +105,12 @@ describe('SessionPersistenceJsonl: durability and crash semantics', () => {
     // nothing on disk yet
     const dir = sessionDir(root, '/work')
     await expect(stat(logPath(root, '/work', m.id))).rejects.toThrow()
-    expect(await ctx.sessionPersistence.has(m.id)).toBe(false)
+    expect((await ctx.sessionPersistence.list()).map(h => h.id)).not.toContain(m.id)
 
     await ctx.sessionPersistence.append(m.id, oneTurnLog())
     // now materialized
     expect((await stat(logPath(root, '/work', m.id))).isFile()).toBe(true)
-    expect(await ctx.sessionPersistence.has(m.id)).toBe(true)
+    expect((await ctx.sessionPersistence.list()).map(h => h.id)).toContain(m.id)
     void dir
   })
 
@@ -448,19 +448,6 @@ describe('SessionPersistenceJsonl: edge cases', () => {
     expect(ids).toContain('big')
   })
 
-  it('has() finds a session on disk under an unknown cwd (cross-bucket scan)', async () => {
-    const m = meta('scan-me', '/somewhere')
-    await ctx.sessionPersistence.create(m)
-    await ctx.sessionPersistence.append(m.id, oneTurnLog())
-    // A fresh backend with no in-memory state → has() must scan disk buckets.
-    const ctx2 = new Context()
-    await ctx2.plugin(SessionStore)
-    await ctx2.plugin(SessionPersistenceJsonl, { root })
-    expect(await ctx2.sessionPersistence.has(m.id)).toBe(true)
-    expect(await ctx2.sessionPersistence.has(SessionId('absent'))).toBe(false)
-    await ctx2.fiber.dispose()
-  })
-
   it('a DIFFERENT live session object reusing a disposed id gets its own init (no stale cache)', async () => {
     // Session A materializes a log under id "reuse".
     const sessFiberA = await ctx.plugin(Object.assign((inner: Context) => {
@@ -579,20 +566,23 @@ describe('SessionPersistenceJsonl: edge cases', () => {
     await ctx2.fiber.dispose()
   })
 
-  it('exists() surfaces a non-ENOENT lookup error (ENOTDIR) instead of reporting absent', async () => {
-    // Same contract on the existence path: a non-ENOENT error from the per-id
-    // open() must surface, not be collapsed to "not found" (which would let a
-    // collision check proceed under a false absence assumption). A LAZY session
-    // (created, never appended) keeps its cwd in state, so has() reaches
-    // loadLive(id, cwd) → exists(logPath). Make that cwd's bucket DIRECTORY a
-    // regular file: open()ing `bucket/<id>.jsonl` under it then fails ENOTDIR.
+  it('loadLive surfaces a non-ENOENT lookup error (ENOTDIR) instead of reporting absent', async () => {
+    // A non-ENOENT error from the per-id open() must surface, not be collapsed to
+    // "not found" (which would let live-adoption proceed under a false absence
+    // assumption). A live session's onCreated reaches loadLive(id, cwd) →
+    // exists(logPath). Make that cwd's bucket DIRECTORY a regular file: open()ing
+    // `bucket/<id>.jsonl` under it then fails ENOTDIR.
     const cwd = '/x'
     const ctx2 = new Context()
     await ctx2.plugin(SessionStore)
     await ctx2.plugin(SessionPersistenceJsonl, { root })
-    await ctx2.sessionPersistence.create(meta('exists-fault', cwd)) // lazy: no bucket yet
     await writeFile(sessionDir(root, cwd), 'x') // bucket path is now a FILE
-    await expect(ctx2.sessionPersistence.has(SessionId('exists-fault'))).rejects.toThrow(/ENOTDIR/)
+    const backend = ctx2.sessionPersistence as unknown as { inits: Map<Session, Promise<void>> }
+    let s!: Session
+    await ctx2.plugin(Object.assign((inner: Context) => {
+      s = inner.sessions.create('exists-fault', { meta: { cwd } })
+    }, { inject: ['sessions'] }))
+    await expect(backend.inits.get(s)).rejects.toThrow(/ENOTDIR/)
     await ctx2.fiber.dispose()
   })
 
@@ -687,7 +677,7 @@ describe('SessionPersistenceJsonl: edge cases', () => {
     circ.self = circ
     await expect(ctx.sessionPersistence.append(m.id, bad(circ))).rejects.toThrow(/non-JSON-serializable/)
     // The session was never materialized by any of the rejected appends.
-    expect(await ctx.sessionPersistence.has(m.id)).toBe(false)
+    expect((await ctx.sessionPersistence.list()).map(h => h.id)).not.toContain(m.id)
   })
 
   it('accepts well-formed JSON values (null, booleans, nested arrays/objects)', async () => {
@@ -695,7 +685,7 @@ describe('SessionPersistenceJsonl: edge cases', () => {
     await ctx.sessionPersistence.create(m)
     const ev = [{ type: 'user/message', seq: 0, time: 1, data: { content: [{ type: 'text', text: 'x' }], source: { kind: 'user' }, extra: { a: null, b: true, c: [1, 2, { d: 'nested' }] } } }] as unknown as SessionEvent[]
     await ctx.sessionPersistence.append(m.id, ev)
-    expect(await ctx.sessionPersistence.has(m.id)).toBe(true)
+    expect((await ctx.sessionPersistence.list()).map(h => h.id)).toContain(m.id)
   })
 
   it('Session.append rejects a non-serializable event at the source (never enters the log)', () => {

packages/session-persistence/session-persistence-sqlite/README.md

@@ -13,8 +13,8 @@ The repo targets Node ≥ 24 (the root `engines` field), which includes the stab
 ## Contract semantics over rows
 
 - **Append = a transaction.** `append` runs `BEGIN`/`COMMIT` around the batch: it materializes the `sessions` row (if still lazy) and INSERTs every event, asserting the contiguous-seq contract first (the first event's `seq` must equal the stored next-seq). A mid-batch failure (a UNIQUE violation on a duplicated seq) rolls back entirely, so the stored log and the in-memory cursor stay consistent. (`load()` already balanced the stored log, so `append` never has to repair a crash tail.)
-- **Lazy materialization.** `create()` records intent in memory only — no row is written until the first `append`. A created-but-never-appended session has no `sessions` row, so it is absent from `has()`/`list()` (which report exactly the sessions that have a row).
-- **Interrupted-turn close on load.** `load()` reads every stored event ordered by `seq` and finds the longest seq-contiguous, parseable prefix — INCLUDING the real events of an interrupted final turn after the last `turn/end` (the loop only flushes at `turn/end`, so a process killed mid-turn leaves real, fully-written rows past it). A single turn can be huge in a long-horizon task, so those events are **preserved, never truncated**: `load()` CLOSES the orphaned turn by durably appending the minimal synthetic boundary events (an error `tool/result` for every assistant tool call left unanswered, a `step/end` if a step was open, then a `turn/end` carrying `{ kind: 'interrupted' }`), inside one transaction that also DELETEs any never-fully-written torn tail row. `load()` is therefore mutating — after it the stored rows are balanced and the cursor is truthful, so the next `append` continues cleanly. The boundary (last `turn/end`, torn-tail detection) is computed from the `seq`/`type` columns so a malformed `data` in a torn tail row is never parsed (discarded, not unloadable). A parse error or `seq` gap inside the committed region (at or before the last real `turn/end`) makes the session unloadable. A session whose only turn never closed keeps its metadata row and stays present in `has()`/`list()` — the same as the JSONL backend, whose file likewise survives a first append that never reached `turn/end`.
+- **Lazy materialization.** `create()` records intent in memory only — no row is written until the first `append`. A created-but-never-appended session has no `sessions` row, so it is absent from `list()` (which reports exactly the sessions that have a row).
+- **Interrupted-turn close on load.** `load()` reads every stored event ordered by `seq` and finds the longest seq-contiguous, parseable prefix — INCLUDING the real events of an interrupted final turn after the last `turn/end` (the loop only flushes at `turn/end`, so a process killed mid-turn leaves real, fully-written rows past it). A single turn can be huge in a long-horizon task, so those events are **preserved, never truncated**: `load()` CLOSES the orphaned turn by durably appending the minimal synthetic boundary events (an error `tool/result` for every assistant tool call left unanswered, a `step/end` if a step was open, then a `turn/end` carrying `{ kind: 'interrupted' }`), inside one transaction that also DELETEs any never-fully-written torn tail row. `load()` is therefore mutating — after it the stored rows are balanced and the cursor is truthful, so the next `append` continues cleanly. The boundary (last `turn/end`, torn-tail detection) is computed from the `seq`/`type` columns so a malformed `data` in a torn tail row is never parsed (discarded, not unloadable). A parse error or `seq` gap inside the committed region (at or before the last real `turn/end`) makes the session unloadable. A session whose only turn never closed keeps its metadata row and stays present in `list()` — the same as the JSONL backend, whose file likewise survives a first append that never reached `turn/end`.
 
 ## Configuration (schemastery)
 

packages/session-persistence/session-persistence-sqlite/src/index.ts

@@ -11,7 +11,7 @@
  * Like the JSONL backend it supplies ONLY the storage primitives (the
  * {@link PersistenceBackend} hooks below — INSERT/DELETE/SELECT inside
  * transactions); all the write-path orchestration lives in the backend-agnostic
- * {@link PersistenceCoordinator} this class composes. The six public
+ * {@link PersistenceCoordinator} this class composes. The four public
  * {@link SessionPersistence} methods delegate to the coordinator.
  *
  * @module @deepseek-ai/dsh-session-persistence-sqlite
@@ -99,14 +99,6 @@ export class SessionPersistenceSqlite extends SessionPersistence implements Pers
     return this.coordinator.load(id)
   }
 
-  has(id: SessionId): Promise<boolean> {
-    return this.coordinator.has(id)
-  }
-
-  delete(id: SessionId): Promise<void> {
-    return this.coordinator.delete(id)
-  }
-
   // `list` is BOTH the public service method and the PersistenceBackend hook —
   // one method (the SELECT below). The coordinator adds no orchestration for
   // listing, so routing it through the coordinator would just recurse. Defined
@@ -203,12 +195,6 @@ export class SessionPersistenceSqlite extends SessionPersistence implements Pers
     }
   }
 
-  /** Remove a session's row (ON DELETE CASCADE drops its events). */
-  async deleteStored(id: SessionId): Promise<void> {
-    await this.ready
-    this.db.prepare('DELETE FROM sessions WHERE id = ?').run(id)
-  }
-
   /** List all materialized sessions' metadata (every row is a materialized session). */
   async list(): Promise<SessionHeader[]> {
     await this.ready
@@ -234,7 +220,7 @@ export class SessionPersistenceSqlite extends SessionPersistence implements Pers
   /**
    * Insert-or-replace a session's metadata row. The only caller is the first
    * materializing `appendBatch`, so writing the row IS the materialization (its
-   * existence is the signal `has`/`list` read).
+   * existence is the signal `list` reads).
    */
   private writeRow(meta: SessionHeader): void {
     this.db.prepare(`

packages/session-persistence/session-persistence-sqlite/src/schema.ts

@@ -21,7 +21,7 @@ export const SCHEMA_VERSION = 2
  * A row of the `sessions` table — the out-of-log metadata ({@link SessionHeader}).
  * The row's EXISTENCE is the materialization signal: it is written only by the
  * first `append` (lazy materialization), so a created-but-never-appended
- * session has no row and is absent from `has`/`list`, mirroring the JSONL
+ * session has no row and is absent from `list`, mirroring the JSONL
  * backend's "no file until first append".
  */
 export interface SessionRow {

packages/session-persistence/session-persistence-sqlite/tests/sqlite.spec.ts

@@ -214,17 +214,15 @@ describe('SessionPersistenceSqlite: durability and crash semantics', () => {
       { type: 'turn/start', seq: 0, time: 1, data: { turn: 1, trigger: { kind: 'message', source: { kind: 'user' } } } },
       { type: 'user/message', seq: 1, time: 2, data: { content: [{ type: 'text', text: 'hi' }], source: { kind: 'user' } } },
     ])
-    expect(await b1.ctx.sessionPersistence.has(m.id)).toBe(true) // materialized
     await b1.dispose()
 
     // A fresh backend loads it: the interrupted (only) turn's real events are
     // preserved and closed with a synthetic turn/end {interrupted} — NOT
-    // truncated. The session was materialized, so has()/list() report it present.
+    // truncated. The session was materialized, so list() reports it present.
     const b2 = await backend(path)
     const loaded = await b2.ctx.sessionPersistence.load(m.id)
     expect(loaded.events.map(e => e.type)).toEqual(['turn/start', 'user/message', 'turn/end'])
     expect(loaded.events.at(-1)!.type === 'turn/end' && loaded.events.at(-1)!.data).toMatchObject({ reason: { kind: 'interrupted' } })
-    expect(await b2.ctx.sessionPersistence.has(m.id)).toBe(true)
     expect((await b2.ctx.sessionPersistence.list()).map(x => x.id)).toContain(m.id)
     await b2.dispose()
   })

packages/session-persistence/session-persistence/README.md

@@ -11,8 +11,7 @@ The persisted unit IS the existing `SessionEvent` (event-sourced model — the l
 | `create(meta): Promise<void>` | Register a new session's metadata. MAY defer the physical write until the first `append` (lazy materialization). |
 | `append(id, events): Promise<void>` | Durably persist a batch (from the `session/flush` drain). Append-only; first event `seq` == stored next-seq after any repair; rejects non-JSON-serializable data naming the offending type. |
 | `load(id): Promise<{ meta; events }>` | Reload meta + log. Preserves an interrupted (unclosed) final turn and closes it with synthetic closers — an error `tool/result` per unanswered `tool-call`, then `step/end?`+`turn/end {interrupted}` (a turn can be huge — never truncated); only a torn tail fragment is dropped. Events contiguous (`events[i].seq === i`); rejects a committed-region gap/parse error or unknown `version`. |
-| `list(): Promise<SessionHeader[]>` | Lightweight listing from metadata, no full-log parse. |
-| `has(id)` / `delete(id)` | Existence / removal. A zero-event lazily-materialized session is absent from `has`/`list`. |
+| `list(): Promise<SessionHeader[]>` | Lightweight listing from metadata, no full-log parse. A zero-event lazily-materialized session is absent from `list`. |
 
 ## Invariants every backend must honor
 
@@ -25,7 +24,7 @@ The persisted unit IS the existing `SessionEvent` (event-sourced model — the l
 
 The two first-party backends were byte-identical (or same-algorithm) for ALL of their write-path orchestration — the in-memory bookkeeping (per-id state, write-behind buffers, per-id serialization chains, per-session init promises), the `session/event` → buffer → `session/flush` drain, lazy materialization, crash-tail repair on load, the four `session/created` adoption cases (new / HMR-adopt / collision / ownerless-claim), and dispose-time quiescence. Only the STORAGE primitives differed (write bytes vs. INSERT rows).
 
-`PersistenceCoordinator` owns that orchestration once. A first-party backend composes one (`new PersistenceCoordinator(ctx, this)`), implements the small `PersistenceBackend` hook interface, and delegates its six public service methods to the coordinator. This keeps the duplicated, correctness-heavy orchestration in a single place (it used to receive the same fixes twice).
+`PersistenceCoordinator` owns that orchestration once. A first-party backend composes one (`new PersistenceCoordinator(ctx, this)`), implements the small `PersistenceBackend` hook interface, and delegates its four public service methods to the coordinator. This keeps the duplicated, correctness-heavy orchestration in a single place (it used to receive the same fixes twice).
 
 The `PersistenceBackend<TornMarker>` hooks (the only seam between the coordinator and storage):
 
@@ -36,7 +35,7 @@ The `PersistenceBackend<TornMarker>` hooks (the only seam between the coordinato
 | `loadLive(id, cwd)` | Read a stored prefix SCOPED to `cwd` (HMR live-adoption must only adopt a log at the SAME cwd; a same-id log elsewhere is a collision, not a resume). A globally-unique-id backend ignores `cwd`. |
 | `appendBatch(meta, events, isMaterialized)` | Durably append a contiguous batch, lazily materializing ATOMICALLY when not yet materialized. |
 | `commitRepair(meta, tornMarker, closers)` | Make a crash repair durable: truncate the torn tail (iff `tornMarker !== undefined` — a marker may be falsy, e.g. seq/offset `0`) and append `closers`. NOT required to be atomic. Used by load (truncate + closers) and live-adoption (truncate only). |
-| `deleteStored(id)` / `list()` | Remove a stored artifact / list all stored metadata. |
+| `list()` | List all stored metadata. |
 | `close?()` | Optional lifecycle teardown (e.g. close a db handle), awaited after the dispose drain. |
 
 The `tornMarker` is fully OPAQUE: the coordinator only tests `!== undefined` and round-trips it to `commitRepair`, never inspecting its value (the JSONL backend uses the byte offset to truncate to, the SQLite backend the seq to delete from). The public `SessionPersistence` service shape is unchanged, so a third-party backend MAY still implement the abstract service directly without the coordinator. See [the write-coordinator RFC](../../../docs/rfc/implemented/architecture/2026-06-18-shared-persistence-write-coordinator.md).

packages/session-persistence/session-persistence/src/coordinator.ts

@@ -14,7 +14,7 @@
  * {@link PersistenceBackend} hook object.
  *
  * The abstract {@link SessionPersistence} service's public API is independent of
- * this: a backend IS a `SessionPersistence` (its six public methods delegate to
+ * this: a backend IS a `SessionPersistence` (its four public methods delegate to
  * a coordinator it composes), so a third-party backend MAY implement the service
  * directly without using the coordinator at all.
  *
@@ -95,9 +95,6 @@ export interface PersistenceBackend<TornMarker = unknown> {
    */
   commitRepair(meta: SessionHeader, tornMarker: TornMarker | undefined, closers: readonly SessionEvent[]): Promise<void>
 
-  /** Remove the stored artifact for `id` (the coordinator clears in-memory state). */
-  deleteStored(id: SessionId): Promise<void>
-
   /** List all stored (materialized) sessions' metadata. */
   list(): Promise<SessionHeader[]>
 
@@ -119,13 +116,12 @@ interface SessionState {
    * SQLite row exists). `create()` registers state LAZILY — cursor 0,
    * materialized false, nothing on disk — so an empty session leaves no
    * artifact and the FIRST `appendBatch` writes the header + its events in ONE
-   * transaction (the "a row exists ⇔ it has events" invariant `has`/`list`
-   * rely on; a separate up-front materialize could crash leaving a row with
+   * transaction (the "a row exists ⇔ it has events" invariant `list`
+   * relies on; a separate up-front materialize could crash leaving a row with
    * zero events). The flag is the only signal that distinguishes a session
-   * registered-but-never-written from one durably present, which two callers
-   * need: `has()` (lazy-but-unwritten is not yet durable) and the reclaim path
-   * (an abandoned id with no artifact AND no buffered events is free to reuse;
-   * a materialized one is a real collision).
+   * registered-but-never-written from one durably present, which the reclaim
+   * path needs (an abandoned id with no artifact AND no buffered events is free
+   * to reuse; a materialized one is a real collision).
    */
   materialized: boolean
   /**
@@ -150,7 +146,7 @@ async function settledErrors(promises: Iterable<Promise<unknown>>): Promise<unkn
 /**
  * Owns the backend-agnostic session write-path orchestration. A backend
  * constructs one (`new PersistenceCoordinator(ctx, this)`), implements
- * {@link PersistenceBackend}, and delegates its six public service methods to
+ * {@link PersistenceBackend}, and delegates its four public service methods to
  * the matching coordinator methods.
  *
  * All per-id operations are serialized (a per-id promise chain) so concurrent
@@ -294,31 +290,6 @@ export class PersistenceCoordinator<TornMarker = unknown> {
   // through the coordinator would only forward to that same hook, so the
   // coordinator stays out of the listing path entirely.
 
-  /** Whether a session is durably present (materialized). */
-  async has(id: SessionId): Promise<boolean> {
-    const state = this.states.get(id)
-    if (state?.materialized) return true
-    // A TRACKED lazy session has a known cwd: probe that exact bucket via
-    // loadLive(id, cwd) — including the no-cwd bucket when its cwd is undefined.
-    // An UNTRACKED id has a genuinely UNKNOWN cwd, so it must scan ANY scope via
-    // loadStored — loadLive(id, undefined) would (correctly) look ONLY in the
-    // no-cwd bucket and miss a materialized session that lives in a real cwd.
-    const probe = state !== undefined
-      ? await this.backend.loadLive(id, state.meta.cwd)
-      : await this.backend.loadStored(id)
-    return probe !== undefined
-  }
-
-  /** Remove a session and all its persisted artifacts. */
-  delete(id: SessionId): Promise<void> {
-    return this.serialize(id, () => this.deleteCore(id))
-  }
-
-  private async deleteCore(id: SessionId): Promise<void> {
-    await this.backend.deleteStored(id)
-    this.states.delete(id)
-  }
-
   // --- per-id serialization + adoption helpers ---
 
   /**

packages/session-persistence/session-persistence/src/index.ts

@@ -103,7 +103,7 @@ export abstract class SessionPersistence extends Service {
   /**
    * Register a new session's metadata. A backend MAY defer the physical write
    * until the first {@link append} (lazy materialization), in which case a
-   * created-but-never-appended session is absent from {@link has}/{@link list}
+   * created-but-never-appended session is absent from {@link list}
    * — abandoned sessions leave nothing behind.
    */
   abstract create(meta: SessionHeader): Promise<void>
@@ -143,12 +143,6 @@ export abstract class SessionPersistence extends Service {
 
   /** Lightweight listing from metadata, without a full-log parse. */
   abstract list(): Promise<SessionHeader[]>
-
-  /** Whether a session is durably present (materialized). */
-  abstract has(id: SessionId): Promise<boolean>
-
-  /** Remove a session and all its persisted artifacts. */
-  abstract delete(id: SessionId): Promise<void>
 }
 
 export default SessionPersistence

packages/session-persistence/session-persistence/tests/contract.ts

@@ -142,24 +142,22 @@ export function runPersistenceContract(name: string, make: () => Promise<Contrac
       }
     })
 
-    it('has()/list() exclude a created-but-never-appended (zero-event) session', async () => {
+    it('list() excludes a created-but-never-appended (zero-event) session', async () => {
       const { persistence, dispose } = await make()
       try {
         await persistence.create(meta('empty'))
-        expect(await persistence.has(SessionId('empty'))).toBe(false)
         expect((await persistence.list()).map(m => m.id)).not.toContain(SessionId('empty'))
       } finally {
         await dispose()
       }
     })
 
-    it('has()/list() include a session once it has events', async () => {
+    it('list() includes a session once it has events', async () => {
       const { persistence, dispose } = await make()
       try {
         const m = meta('s2')
         await persistence.create(m)
         await persistence.append(m.id, oneTurnLog())
-        expect(await persistence.has(m.id)).toBe(true)
         expect((await persistence.list()).map(x => x.id)).toContain(m.id)
       } finally {
         await dispose()
@@ -227,19 +225,5 @@ export function runPersistenceContract(name: string, make: () => Promise<Contrac
         await dispose()
       }
     })
-
-    it('delete removes a session', async () => {
-      const { persistence, dispose } = await make()
-      try {
-        const m = meta('s6')
-        await persistence.create(m)
-        await persistence.append(m.id, oneTurnLog())
-        expect(await persistence.has(m.id)).toBe(true)
-        await persistence.delete(m.id)
-        expect(await persistence.has(m.id)).toBe(false)
-      } finally {
-        await dispose()
-      }
-    })
   })
 }

packages/session-persistence/session-persistence/tests/coordinator-contract.ts

@@ -625,7 +625,7 @@ export function runCoordinatorContract(name: string, makeFixture: () => Promise<
         const m = meta('empty-batch', WORK)
         await ctx.sessionPersistence.create(m)
         await ctx.sessionPersistence.append(m.id, [])
-        expect(await ctx.sessionPersistence.has(m.id)).toBe(false)
+        expect((await ctx.sessionPersistence.list()).map(h => h.id)).not.toContain(m.id)
       } finally {
         await fiber.dispose()
         await fix.cleanup()
@@ -643,17 +643,6 @@ export function runCoordinatorContract(name: string, makeFixture: () => Promise<
       }
     })
 
-    it('delete of a non-existent session is a no-op', async () => {
-      const fix = await makeFixture()
-      const { ctx, fiber } = await freshCtx(fix)
-      try {
-        await expect(ctx.sessionPersistence.delete(SessionId('ghost'))).resolves.toBeUndefined()
-      } finally {
-        await fiber.dispose()
-        await fix.cleanup()
-      }
-    })
-
     it('create rejects a duplicate id (in memory and on a persisted log)', async () => {
       const fix = await makeFixture()
       const first = await freshCtx(fix)

packages/session-persistence/session-persistence/tests/persistence.spec.ts

@@ -61,14 +61,6 @@ class MemoryPersistence extends SessionPersistence implements PersistenceBackend
     return this.coordinator.load(id)
   }
 
-  has(id: SessionId): Promise<boolean> {
-    return this.coordinator.has(id)
-  }
-
-  delete(id: SessionId): Promise<void> {
-    return this.coordinator.delete(id)
-  }
-
   /** White-box accessor: await a specific session's onCreated init. */
   get inits(): Map<Session, Promise<void>> {
     return this.coordinator.inits
@@ -114,10 +106,6 @@ class MemoryPersistence extends SessionPersistence implements PersistenceBackend
     if (closers.length > 0) entry.events.push(...structuredClone(closers) as SessionEvent[])
   }
 
-  async deleteStored(id: SessionId): Promise<void> {
-    this.store.delete(id)
-  }
-
   async list(): Promise<SessionHeader[]> {
     return [...this.store.values()].map(e => structuredClone(e.meta))
   }