# Protocol Backlog Backend RPC methods and event types exposed by the ZCode CLI (`zcode app-server`) that are **not yet wired into the bridge**, tracked for potential future support. Last audited against **app-server 0.16.5 bundled in ZCode desktop 3.12.3** (2026-09-18; the CLI still self-reports "0.16.5" across desktop versions — the app version, not the CLI string, dates a bundle). Method names were extracted from the `zcode.cjs` method-name enum (`session/create` → 65 entries) and the v4 enum; event types from the zod event-envelope union. **Source of truth (2026-09-21)**: ZCode open-sourced — local checkout at `~/Develop/NoBackup/ZCode` (remote `github.com/zai-org/ZCode`; desktop 3.14.0 = app-server `apps/zcode-cli` 0.16.9, the exact binary the bridge runs). The protocol enum and zod schemas live unminified at `packages/shared/src/zcode-protocol/index.ts`; the protocol server dispatch at `apps/zcode-cli/packages/bootstrap/src/zcode-protocol/` (server.ts, server-operations.ts); the agent runtime at `apps/zcode-cli/packages/core/` (`packages/zcode-server-cli` is only a thin CLI shell). Prefer reading source over the bundle-extraction method in "Verification method" (kept for released versions newer than the checkout — pull the checkout before auditing a new version). Full audit detail with `file:line` evidence: `.zcode/scratch/alignment-protocol.md` (protocol surface) and `.zcode/scratch/alignment-hacks.md` (Gotchas verification). **3.14.3 audit (2026-09-24, commit `328c1a0` — no bridge impact)**: the single upstream release commit is entirely the dynamic-workflow subsystem (runtime concurrency adjustment, modify/restart reuse, large-run status rendering, script-submit token cost) plus bot delivery (`botDeliveryTarget` on `session/send` and `automation/create` — both OPTIONAL fields the bridge never sends — and the bots providers: feishu/telegram/weixin/webhook). app-server stays `0.16.9`; `server-operations.ts` touches only the botDeliveryTarget passthrough (stop's `activeAbortController` and compact's `state.updated` swallow unchanged); provider bootstrap / runtime headers / setModel / goal / fork untouched. `bundled-skills.ts` is the DWF skill pack's own distribution channel (explicitly not in the settings page or `$` panel) — no overlap with the bridge's filesystem skill discovery. **3.14.0 audit (2026-09-20, app-server 0.16.9 — live-probed end to end)**: the dynamic-workflow family (ten model tools led by `CreateWorkflow`) is OFF by default headless and enabled per PROCESS via `workspace/updateDynamicWorkflowPolicy` — the flag is process-global (the `workspace` param is echoed, never used for lookup), has no persistence, and mid-session flips do not reach live sessions. The `session/requestRuntimePreferences` response schema is `.strict()` and cannot carry the flag; `session/create` / `session/resume` accept a `dynamicWorkflowEnabled` param that ORs with the global. (Source-confirmed 2026-09-21: the in-agent gate defaults ON — only an explicit `false` removes the tools — so the fail-closed default lives only at the protocol layer and the per-session create param is sufficient; closing the gate also removes the `dynamic-workflows` skill and `/workflow` command, `core/src/tool/handlers/index.ts:177-183`, `bootstrap/src/app/create-app.ts:755-807`.) Run observability lives OUTSIDE the `session/event` stream: `workflow.lifecycle` (phases are exactly `actor-spawned` / `run-settled`) arrives on `v4/telemetry/event`, and `sess_dwf-*` child sessions push their turn/tool events on `computer-use/operation-event`. Bridge wiring (opt-in enable + narrow observability tap) is designed in ADR-0024, not yet implemented. ## Removed upstream in 0.16 (verified live: `-32601`) | Method | Replacement | Bridge action | | ----------------------- | ---------------------------------------------------- | --------------------------------------------------- | | `session/steer` | v4 command/conversation API | Dropped the ACP extension + `/steer` slash command | | `session/rewind` | `v4/conversation/fileRewindPreview` + v4 rewind flow | Dropped the ACP extension + `/rewind` slash command | | `session/rewindCascade` | v4 rewind flow | Dropped the ACP extension | Also absent from the 0.16.9 method enum (source-verified 2026-09-21 — bundle audit had kept them as candidates or "not planned"): the whole workspace-defaults/provider cluster — `workspace/readState`, `workspace/setDefaultMode`, `workspace/setDefaultModel`, `workspace/setDefaultThoughtLevel`, `workspace/upsertModelProvider`, `workspace/removeModelProvider`, `workspace/updateProviderRegistry`. The only `workspace/*` methods left: `readPresentation`, `hooks/trustGrant`, `updateInteractionPreferences`, `updateModelIoPreferences`, `updateOffPeakToolPolicy`, `updateDynamicWorkflowPolicy`, `generateText`, `cancelGenerateText` (`index.ts:3597-3611`). `session/fork` (branch from checkpoint) is the remaining v3 alternative for rewind-like UX. The backend still emits `rewind.triggered` / `checkpoint.created` events, so a client can observe rewinds initiated elsewhere. ## Deprecated in source (0.16.9 enum comments, wire cases kept) The protocol enum now labels these `@deprecated` (`index.ts:3573-3645`); wire cases remain, so calls still work, but plan for the v4 successors: | Method | Source note | Bridge call site | | ------------------------------ | --------------------------------------------------------------------------------------------------- | ----------------------------------- | | `session/send` | Main path converged on v4 `sendText`; only the adapter-attachment fallback branch still consumes | the turn loop (fine until v4 lands) | | `session/stop` | Host client method deleted (stop converged on the v4 stop command) | `stopBackendTurn` (dual-send) | | `session/cancelBackgroundTask` | Replacement: v4 `cancelBackgroundWork` | `handlers/extensions.ts` | | `session/fork` | Desktop host client chain deleted; v4 `forkAssistant` (via `forkSessionAtMessage`) is the successor | `handlers/extensions.ts` | | `usage/stats` | Host consumption moved to `v4/usage/stats`; wire-compat case only | not used | | `session/usage` | Host moved to `v4/conversation/usage`; slated for removal with `usage/stats` | candidate only | ## Candidate methods (optional enhancements) Available in the backend but with no ACP-side counterpart yet. Pick them up when a concrete ACP/editor need appears. Ranked shortlist in "Alignment opportunities" below. | Method | Purpose | Current bridge behavior | | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `session/subagents` (`index.ts:1520-1618`) | Sub-agent states: `running{status: running\|waiting\|blocked}`, `ended{total, items[{status: success\|failed\|cancelled\|lost}], nextCursor}` | Sub-agent info is parsed from the `Agent` tool result (`_meta.subagent`); the RPC adds waiting/blocked/lost states for stuck-subagent detection (pairs with the watermark liveness logic in `runEventTurn`) | | `session/events` (`{sessionId, afterSeq?, limit?}`, `index.ts:1667-1674`) | Pull-mode event history | Not used; gap-fill after the drain gate's close-escalation reload (re-subscribe + replay only the missed window), durable audit for `/debug` | | `session/subscribe` `afterSeq` + `includeSnapshot` (`index.ts:1496-1513`) | Resume the event stream from a seq watermark, optionally with a full state snapshot | Not used; crash-safe resubscribe instead of full replay | | `session/usage` / `v4/conversation/usage` | Per-session cumulative usage: input/output/reasoning/cache tokens, `modelRequestCount`, `modelErrorCount` (`index.ts:1627-1646`) | Per-turn billing usage is now carried on the ACP `session/prompt` result (`usage` + `_meta.zcode.usage`), sourced from `turn.completed`; this RPC remains a candidate for session-cumulative reconciliation (deprecated upstream, see table above) | | `session/compact` `instructions` + `result.compact` (`index.ts:1829-1853`) | Custom compact instructions; result acks `{state: accepted\|already_running, inputId?, operationId?}` | Not forwarded — `/compact ` could pass instructions; the backend's own `already_running` ack can backstop the bridge's `autoCompactInFlight` single-flight | | `session/debug` (`index.ts:3571`, `bootstrap/src/zcode-protocol/session-debug.ts`) | Per-session debug snapshot accumulated from the live event stream | Not used; `zcode-acp` diagnostics command / `/debug` extension | | `session/list` rich params (`sessionIds` incl. hidden, `includeArchived`, `limit`, `index.ts:1600-1609`) | Explicit identity lookup, archived sessions | Not used | | `session/create` extras: `toolAllowlist`/`toolDenylist` (per-session tool face — could move Cron* hiding off process-wide `--disallowed-tools`), `importedHistory` (claudeCode / sharedContext+sha256 provenance), `persistence:"immediate"\|"deferred"`, `titleGenerationEnabled:false` (bridge sets its own titles), `parentSessionId` (`index.ts:1558-1580`) | Session-creation knobs | Not forwarded; `session/resume` also takes `toolAllowlist`/`toolDenylist` — a resume WITHOUT them drops the tool face on cold recovery (`index.ts:1589-1595`) | | `mcp/list` `mode:"status"` (`index.ts:686-723`) | Status without connecting: per-server `{status, transport, toolCount, failureKind(19-value enum), authorization{authorizationUrl}}` | Not used; editor MCP health panel + OAuth start URL without new transport | | `process/childProcesses` (3.12.3) | List a session's child processes (`{pid, serverName, mcpSource, pluginName?}`, pure memory) | Not used; potentially useful for background-task diagnostics | | `skills/referenceCatalog`, `plugins/referenceCatalog[WithCategory]` (categorized variant new in 0.16.9) | Session-scoped FROZEN catalogs — the authoritative per-session view vs the bridge's live disk reads | Not used; fixes the stale-catalog class of bug (backend freezes discovery at session start) | | `workspace/readPresentation` (3.12.3) | The backend's own view of workspace mode + slash-command list | Not used; cross-check the bridge's disk-based slash discovery for drift | | `workflows/*` family (NEW 0.16.9: `list/get/updateMeta/delete/runs/move`, `index.ts:2685-2937, 3618-3625`) | Session-less management of saved dynamic workflows (`/.zcode/workflows/`, project+global scopes), run history with `artifacts`, cross-cwd runs query | **WIRED (2026-09-24, ADR-0029)**: proxied under `/settings/workflows*` + the local `/workflows` slash listing; availability is the remote `/client/configs` verdict (`src/config/workflow-gate.ts`), and `v4/command startSavedWorkflow`/`resumeWorkflowRun` + the `workflowRun*` queries are wired with it (see the v4 section below) | | `provider/testModelConnectivity` (3.12.3) | Probe a provider/model endpoint | Not used; model availability comes from the `session/create` response | | `runtime/capabilities` (3.12.3; returns `{independentPlanState:true}`) | Trivial capability handshake | Not used; cheap preflight for a `zcode-acp doctor` command | | `interaction/providerRuntimeHeadersCancelled` notification (`index.ts:336, 2396-2406`) | Backend cancels a pending runtime-headers refresh (workspace/session/requestId scoped) | Not handled; drop pending answerers immediately on turn cancel instead of waiting them out | | `workspace/generateText` / `workspace/cancelGenerateText` (0.16.5) | Workspace-scoped one-shot text generation | Not used; no ACP counterpart | | `workspace/updateInteractionPreferences` / `workspace/updateModelIoPreferences` | Client preference updates | Not used | | `offPeak/{create,list}`, `workspace/updateOffPeakToolPolicy` (3.12.3) | Off-peak (discounted-hours) task family | Not used; `session/send` carries the matching `offPeakTaskId`/`offPeakRunType` params — candidate if a client wants to schedule discounted-hours runs. Off-peak tools are fail-closed at the protocol layer with three unlock channels (per-session param OR'd, process policy method, `offPeakPort` injection) | | `automation/{create,update,list,delete,checkTaskBinding}` (3.12.3) | Scheduled (cron) task family — served by the host over `automation/*` requests | Not planned (see below) | | `plugins/{list,setEnabled,overview,install,uninstall,update,cancelOperation,restoreBuiltin,configure,resetConfig,validate,describe}` + `plugins/marketplace/{add,remove,update}` (3.12.3) | Full plugin management + marketplace family | Not used — **compat watchpoint**: if upstream moves plugin distribution to the marketplace, the bridge's disk-based discovery (`config/plugin-commands.ts`) may go stale | ### `session/send` params (0.16.9-verified, `index.ts:1730-1768`) Actual field list: `sessionId, modelSelection, modelExecution, inputId, queryId, content, attachments, browserAmbientContext, expectedRevision, expectedProviderRevision, automationId, offPeakTaskId, offPeakRunType, toolDenylist`. Not forwarded by the bridge today: - `modelSelection` — per-message model override `{providerId, modelId, options:{reasoningLevel?}}` (`packages/shared/src/model-selection.ts`); the previously-listed `runtimeModel` does NOT exist in 0.16.9 (bundle-audit error). Enables per-turn model switching without a `session/setModel` round-trip. - `modelExecution` — requires `modelSelection` (superRefine); carries per-turn credentials `requestAuth:{apiKey?, headers?}` plus sub-agent policy (`subagents:{foregroundModel, background}`) and `memoryExtraction:"skip"`. Complements `answerProviderRuntimeHeaders`. - `toolDenylist` — per-message tool deny list. - `browserAmbientContext` — browser context for the turn. - `expectedRevision` / `expectedProviderRevision` — optimistic concurrency guards. (`expectedModelRuntimeRevision`, previously listed, does not exist.) - `automationId` / `offPeakTaskId` / `offPeakRunType` — scheduled/off-peak tasks. ### Event vocabulary (0.16.9 envelope union — exactly 25 types, `index.ts:1100-1126`) `session.created`, `session.resumed`, `session.updated`, `session.titleUpdated`, `session.closed`, `turn.started`, `turn.steerQueued`, `turn.steerDrained`, `turn.completed`, `turn.failed`, `message.upserted`, `message.removed`, `part.started`, `part.delta`, `part.upserted`, `part.removed`, `model.streaming`, `tool.updated`, `permission.requested`, `permission.resolved`, `userInput.requested`, `userInput.resolved`, `checkpoint.created`, `rewind.triggered`, `streamRecovery.updated`. Notes per type (the ones with known bridge relevance): | Event | Notes | | ------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `session.titleUpdated` | **Wired** — `SessionTitleListener` adopts `generated`/`custom` pushes | | `message.upserted` / `message.removed` | Message-granular upsert/remove; the projection differ reconciles instead | | `part.started` / `part.delta` / `part.upserted` / `part.removed` | Message-PART granular streaming (the v4 conversation model on the v3 envelope) | | `permission.requested` / `permission.resolved` | Interaction lifecycle OBSERVER events; the bridge serves the request methods | | `userInput.requested` / `userInput.resolved` | Same, for user-input interactions | | `checkpoint.created` / `rewind.triggered` | Checkpoint + rewind lifecycle (rewinds initiated elsewhere are observable) | | `streamRecovery.updated` | Stream recovery progress — payload is an untyped `jsonObjectSchema` upstream; useful for the replay/gap-fill path | | `turn.started` payload extras (`index.ts:1168-1186`) | `executionKind:"agent"\|"controlOnly"` (controlOnly = no model turn — the bridge's own boot-resume ack could be classified by this instead of text-matching), `foregroundExecutionId` (feeds the precise v4 stop), `backgroundSource`, `intent`, `originMeta` | | `turn.steerQueued` / `turn.steerDrained` payloads (`index.ts:1191-1229`) | Queue length, `commandKind`, `delivery`, `targetTurnId`, drained `injectedMessageIds` — enough to render a proper "queued behind running turn" ACP update. Steer is only reachable via v4 delivery semantics (see Gotchas) — a steer caused by ANOTHER client on the same backend is visible here | | `turn.completed` `resultType` + `cacheStats` (`index.ts:1230-1261`) | `resultType: success\|cancelled\|error_max_turns\|error_max_budget\|error_during_execution\|error_max_tool_calls`; `cacheStats{totalMessages, cachedMessages, lastCacheHit, cacheReadTokens?}` — rich terminal lines + cache-health visibility | | `turn.failed` `turnPhase` (`index.ts:1262-1269`) | Failure phase string for better triage | | `model.streaming` kinds (`index.ts:987-1014`) | 13 kinds incl. `reasoning_*` deltas — relevant if thinking streams are ever surfaced directly | | `session.updated` with `state.updated` mutation reasons | Compact terminal state IS observable here: `session_compacted` / `session_compact_cancelled` / `session_compact_failed` (source: `server-operations.ts:2082-2119`) — the bridge can report real compact failures instead of assuming success from the RPC ack | **Corrected 2026-09-21 (source)**: `rewind.started` / `rewind.failed` / `rewind.completed`, `turn.attachments.resolved`, `usage.delta`, and `turn.terminal` are NOT in the 0.16.9 union — bundle-audit false positives; rows removed. Unknown event types fall through the translator's else-chain untranslated and silently — new backend events never produce noise or errors, so additions here are informational, not blocking. Not on this stream (verified live 2026-09-20, 3.14.0): `workflow.lifecycle` arrives on `v4/telemetry/event`, and `sess_dwf-*` workflow child sessions push their own turn/tool events on `computer-use/operation-event`; neither is a `session/event` type. The bridge ignores both channels today — the workflow observability design (ADR-0024) taps them narrowly and re-attributes child events to the parent session. ### CLI→host notifications (bridge IS the host — currently ignored) `startup/storageState` (DB phases checking/waiting_for_lock/migrating/ committing/ready/failed — could drive a real "backend starting" indicator; control frames `startup/storagePath|storagePrepared|storagePathReady`), `process/mcpTelemetry` (process_start/process_crash/session_startup/memory), `process/mcpResourceSamples` (5-min MCP RSS/CPU), `process/toolExecResource` (bash completion facts), `process/resourceSample`, `plugins/operationProgress` (`index.ts:334-451, 3696-3713`). ## v4 protocol family (strategic) 0.16 ships a parallel **v4** API used by the desktop client, alongside the v3 `session/*` surface this bridge speaks. Full method table: `packages/shared/src/zcode-protocol-v4/transport.ts:307-359` (larger than the list below — see source for the authoritative set). `v4/connection/flow`, `v4/controller/{subscribe,resync,unsubscribe}`, `v4/conversation/{subscribe,resync,unsubscribe,rowsRange,plans,fileChanges, fileRewindPreview,usage,attachmentRead,attachmentStat,frame,backgroundBashOutput, workflowRunEvents,workflowRuns,workflowRunArtifacts,workflowRunArtifactData, workflowRunArtifactRead,workflowRunWorkspace,workflowRunNodeResult}`, `v4/attachment/{begin,chunk,commit,abort,read,previewSource}` (≤512KiB chunks), `v4/usage/stats`, `v4/conversation/usage`, `v4/commands/query` (idempotency probe), `v4/command`, `v4/command_fact`, `v4/shared_context_import`, `v4/telemetry/event`, `v4/telemetry/local-ttft`, `v4/cua/permission-observation`, `v4/fork_start_failure`. Topic model (`transport.ts:83-161`): subscribe with `{topic, base:{logEpoch, seq}, visibility}` → ACK `{subscriptionId, mode: snapshot|resume, logEpoch}`; frames are `(fromSeq, toSeq]` deltas — the watermark/CAS vocabulary row-targeting commands require (`baseRevision` + `baseLogEpoch`, `command.ts:293-317`). The bridge already speaks `v4/command` (the dual stop), and since 2026-09-24 also `startSavedWorkflow` / `resumeWorkflowRun` (Settings API launch routes, ADR-0029 — the ack is terminal, awaited via `request()`) plus the seven `v4/conversation/workflowRun*` read queries (run progress poller + run-detail routes). The launch consent is the API call itself (upstream skips the permission popup for hub clicks). Its payload union (`command.ts:43-244`) is a single-method stepping stone to rewind/edit-turn/feedback/queue UX over ACP without implementing the v4 subscription mesh: `sendText (requestedDelivery startNow|queue|guide, heldQueueDisposition)`, `stop (expectedForegroundExecutionId — obtainable from `turn.started`; the CLI uses it to reject late stops that would kill a newer unrelated execution)`, `compact`, `forkAssistant`, `applyFileRewind`, `editUserQuery`, `retryTurn`, `setAssistantFeedback`, queue ops (`sendQueuedNow`, `editQueueItem`, `reorderQueueItem`, `deleteQueueItem`, `setAutoDrain`), `resolveInteraction`, `snoozeInteractionAutoResolution`, `switchModelConfig`, `switchCollaborationMode (build|edit|plan|yolo)`, `pauseGoal`/`resumeGoal`, `cancelBackgroundWork`, workflow ops (`startSavedWorkflow`, `resumeWorkflowRun`, `amendWorkflowRunSettings`), `renameSession`, `deleteSession`, `discardSharedContext`. Hook trust is also v4 now: `respondWorkspaceHookReview` / `toggleWorkspaceHookReviewItem` / `revokeWorkspaceHookTrust` / `requestWorkspaceHookReview` (`command.ts:186-200`). The v3 `workspace/hooks/trustGrant` is CLI-HOSTED (host→CLI; the CLI's dispatch handles it — `bootstrap/src/zcode-protocol/server.ts:607-625`), so the bridge will never RECEIVE it (previous BACKLOG framing was wrong). ## Not planned (client/config layer) These methods belong to the desktop client or workspace configuration layer and have no ACP equivalent. Listed for completeness only — the bridge does not intend to surface them. `automation/*` (scheduled tasks), `usage/stats`, `workspace/generateText`, `workspace/cancelGenerateText`, `mcp/list` (connect mode), `plugins/*` (the bridge reads plugin commands from disk instead). **Automation tool gating, corrected against source (2026-09-21)**: there is NO backend env gate — `ZCODE_ENABLE_AUTOMATION_TOOLS` exists only in the bridge (`src/backend/resolve.ts`). The backend registers `CronCreate/CronList/ CronUpdate/CronDelete` whenever an `automationPort` is injected (`core/src/runtime/helpers/runtime-tools.ts:66`), and the legacy protocol server injects one for every session create (`server-operations.ts:3370`) — so the backend ALWAYS registers them in app-server mode. Opting out is entirely the bridge's `--disallowed-tools` (or per-session `toolDenylist`). Bonus: `AUTOMATION_MUTATION_TOOL_NAMES = [CronCreate, CronUpdate, CronDelete]` gets special turn-loop treatment (`turn-loop-state.ts:23`). ## Alignment opportunities (2026-09-21, source-verified — ranked) Status markers updated after the 2026-09-21 implementation pass. Details and `file:line` in `.zcode/scratch/alignment-protocol.md`. 1. ~~**Precise ESC**~~ **WIRED (already present)** — `stopBackendTurn` already captures `foregroundExecutionId` from `turn.started` and sends it in the v4 stop, with a compaction guard for never-started turns; the source pass only corrected the outdated comment. 2. ~~**`/compact `**~~ **WIRED** — instructions forwarded (trimmed); `already_running` ack surfaced; falls through to the same lock wait. 3. ~~**Real compact failure reporting**~~ **WIRED** — `state.updated` reasons (`session_compact_failed`/`_cancelled`) recorded via `ZcodeBackend.onCompactOutcome` → `server.compactOutcomes`; compact() reports `__compactFailed` (slash + auto-compact paths); usage refresh suppressed on failure. Regression tests: `tests/compact-outcome.test.ts`. Bonus fix from the same source pass: `waitForTurnIdle`'s lock probe now matches 0.16.9's "A prompt is already running" wording (previously only the 0.16.5 "prompt is running" substring — on 0.16.9 every probe fell to the NON-LOCK branch and relied on the 30s grace). 4. ~~**Drain-gate simplification**~~ **WIRED (behavior-adaptive, 2026-09-21)** — `server.observedSendBusyReject`: once this backend process has rejected a send with -32010 "A prompt is already running for this session" (code AND message — -32010 is shared by unrelated errors), the drain gate's pre-send poll (and its close-escalation) is skipped and the send busy-retry loop is the single authority. Parity kept: one-shot queued note on busy waits, post-accept differ re-baseline (`sendAttempt > 1` ⇒ the abandoned turn unwound during our retries). Backends that never showed the rejection keep the full legacy gate. Regression tests: `tests/drain-gate-fast-path.test.ts`. 5. ~~**`session/subagents`** + **`session/events` afterSeq**~~ **WIRED (2026-09-21)** — sub-agent status text lines during silent phases: the stall-reconcile probe polls `session/subagents` and surfaces roster CHANGES as one-line `agent_message_chunk` updates (running/waiting/blocked - a one-shot ended summary with failed/cancelled counts; best-effort, -32601 backends are silent). Gap-fill landed via the ALREADY-WIRED subscribe channel instead of the pull RPC: `resubscribe` consumes the missed window the backend returns IN the subscribe response (`events`, seq-ordered, deduped against the watermark), and the initial `subscribe` now OMITS `afterSeq` — the old explicit `afterSeq: 0` made the backend materialize the FULL event log into a response the bridge discarded, every turn. `session/events` itself stays a `/debug`-only candidate. Regression tests: `tests/subagent-status.test.ts`, `tests/resubscribe-gap-fill.test.ts`. 6. ~~**`mcp/list mode:"status"`**~~ **WIRED (2026-09-21)** — `/mcp` upgraded to a live health panel (per-server `name · status · N tools · failureKind`, OAuth `authorizationUrl` indented beneath its server; any RPC failure falls back to the local-discovery card). Regression tests: `tests/mcp-health.test.ts`. 7. ~~**Retire `session/updateRuntimeModelConfig`**~~ **DONE** — the ACP extension method and handler were removed (absent from the 0.16.9 enum, every call answered -32601); `setModel` + `applyModelSwitch` cover the path on all builds. 8. ~~**Cancel stale header answerers**~~ **DONE (minimal)** — the responder answers at frame arrival, so nothing is ever pending; `interaction/providerRuntimeHeadersCancelled` is now logged-and-acked instead of silently ignored. 9. ~~**`turn.completed` `resultType`/`cacheStats`**~~ **WIRED (2026-09-21)** — one turn-end status line per reply (agent_message_chunk, distinct messageId): success renders prompt-cache stats (`cache N/M messages · cache-read tokens`), non-success resultTypes surface verbatim as a warning line. Regression tests: `tests/turn-info-line.test.ts`. 10. **Per-session `toolDenylist` at create/resume** — move Cron* hiding off process-wide `--disallowed-tools`; note a resume WITHOUT the lists drops the tool face on cold recovery. PENDING. 11. **v4/command channel** as the single implementation surface for rewind/edit/feedback/queue UX later. PENDING. ## Verification method The bundled CLI is minified, so a literal `grep "session/rewind"` returns 0 hits even when the method is fully supported — and vice versa, string absence proves nothing. To audit reliably: ```sh cd /Applications/ZCode.app/Contents/Resources/glm # 1. Extract the RPC dispatch switch (all `case XX.method:` labels). # The `default:` branch throws -32601, so a method with no case is gone. python3 - <<'EOF' import re src = open('zcode.cjs', encoding='utf-8', errors='replace').read() i = src.find('case rr.sessionCreate') start = src.rfind('switch', 0, i) cases = re.findall(r'case (?:rr|Pc)\.([a-zA-Z]+)', src[start:start+20000]) print(' '.join(dict.fromkeys(cases))) EOF # 2. Confirm with a live call — the envelope has NO `jsonrpc` field: # {"id":1,"method":"session/steer","params":{...}} → -32601 means removed. ``` Never conclude a method was removed from a single string-literal search; a missing dispatch case plus a live `-32601` is the proof. With the open-source checkout available, prefer reading `packages/shared/src/zcode-protocol/index.ts` - the dispatch switch in `apps/zcode-cli/packages/bootstrap/src/zcode-protocol/server.ts` first; fall back to this method only for released versions newer than the checkout.