dsh-ctm — Context Transparency Manager

English | 中文

Turns the model's context into a visible, editable, effectiveness-scored first-class object, published as a self-contained bundle plugin for DeepSeek Harness.

Features

• Full visibility: a turn → segment flow view colored by role / tokens / cache status / effectiveness, with markdown rendering and paging.
• Token accounting (provider-measured): the KPI strip uses MECE buckets — uncached input / cache hit / output (cache write appears separately only when > 0) — plus a derived cache hit rate (hit ÷ bucket sum; hidden when the denominator is 0) and the model. All figures are whole-session cumulative, read preferentially from the tokenUsage session projection, falling back to a full-log event fold when the projection is unavailable (the summary's usageSource marks which path was taken). Turn headers show the sum of that turn's step requests; step headers show that single request's measured usage (tooltips state the exact semantics); the latest request's prompt size and context-window occupancy (when the contextPressure projection is readable) sit in the KPI tooltip. Segment-level token counts remain local heuristic estimates and are explicitly labeled as estimates.
• Live refresh: event-driven (reactive useSession subscription) — new messages, tool results and turn boundaries update immediately; no polling.
• System prompt: Session V3 compatible. CTM treats the newest system/message on the current surface as the editable effective system prompt and displays it under the stable segment-0 identity; migrated historical sessions use the same path.
• Editable: replace, delete, rollback, snapshot restore, undo, effectiveness override (manual), and copy segment content (to re-send a rolled-back message, copy the original into the host input box — the host chat UI does not expose its input box to plugins). The initial system prompt is replaceable; all other system-injected content (runtime context etc.), tool results, and CTM placeholder markers are read-only in the UI.
• Effectiveness engine: automatic effective / redundant / stale / injected verdicts with manual override. The 2-gram similarity sets are LRU-cached (500-entry cap), never rebuilt from scratch per request.
• Apply for real (off by default): when enabled, replace / delete / rollback no longer intercept requests — they are written into the session log as surface replace events at agent/pre-step (same timing, same mechanism as official compaction), honoring DSH's model-visible ⟺ logged invariant: replay / fork / token accounting always match what the model actually saw. Edits are badged "pending" until logged. Deletes and rollbacks are carried by placeholder user/message nodes (grouped under "User input" in the UI, read-only protected — not classified as system injections); assistant revisions are carried as user messages by role demotion; tool-call/result pairs are never split (deletion always shadows a minimal balanced range: deleting a tool result absorbs the assistant message carrying its tool-call, so the model never sees a dangling call). Undo = a queued (not yet logged) edit is simply dequeued; an already-logged edit is reversed by a counter-replace with the original content (only the most recent operation is undoable); undoing a rollback or a multi-node delete uses a restore group: the placeholder node is replaced by the first shadowed item and the rest append to the tail in original order, all demoted to user messages (an append-only log cannot re-add assistant/tool roles), and a restore group is itself undoable (undoing it re-shadows the run). Logging failures are recorded and surfaced at the top of the view. Mutations carrying expectedVersion are checked optimistically — a version mismatch rejects the request with zero side effects.
• System prompt editing: a replacement of segment 0 is stored as an override and swapped into the section list by the system-prompt/assemble waterfall at the next prompt assembly; the agent loop logs the valid system/message replacement.
• i18n: Chinese / English UI.
• Zero coupling: host↔client runs over plain HTTP POST /ctm — no Typert @Remote / dsh-api-remotes; zero runtime dependencies (the tool-pair balance check is re-implemented locally instead of depending on @deepseek-ai/dsh-compaction).

Architecture

src/
├── contract.ts       # shared contract: TS types + Zod runtime validation (single source of truth)
├── host.ts           # host half: POST /ctm route + the agent/pre-step & system-prompt/assemble waterfalls
├── usage.ts          # MECE bucket conversion / summation / full-log fold for usage (pure logic, unit-tested)
├── surface-edits.ts  # edit logging layer: replace-event construction, tool-pair balancing, edit-queue application (pure logic, unit-tested)
├── bigrams.ts        # 2-gram sets + LRU cache for the effectiveness engine (pure logic, unit-tested)
└── client/           # browser half: conversation.view tab + fetch('/ctm')

• contract.ts: the host validates requests with it, the client validates responses with it. Types are inferred from Zod schemas, and runtime validation provides cross-version tolerance — the key to a community plugin shipping on its own cadence. New fields are always .optional() (e.g. segment pending, usage; state applyError); the single exception was the summary usage rework (old inputTokens/cachedTokens/... → MECE total/lastRequest/usageSource) — host and client ship in one package, so that one breaking change was made directly.
• host.ts: registers POST /ctm via webServer; injects sessionQuery / sessions / tokenMeter. Reads Session V3 surface events from readSurface, marks the newest system/message as the stable system-prompt segment 0, reads full logs through snapshotEvents(), and resolves individual events through eventAt(). Usage has two channels: assistant segments carry the provider-measured usage of a single request from the assistant/message event; session-level totals prefer sessionProjections.snapshot() (an optional service captured through an ctx.inject child context — cordis throws on any read of a service not declared in inject, optional chaining does not help) for the tokenUsage / contextPressure projections — the projection folds the complete log, immune to compaction/shadowing — falling back to summing the full log event by event (correct but O(log) per read), with the summary's usageSource marking the channel actually used. With apply for real on, edits enter a per-session queue and are appended group by group in the agent/pre-step waterfall (the turn is open and the request not yet built, so edits take effect in that very request; edits to an idle session queue up and land on the next step). The system-prompt override swaps the whole section list in the system-prompt/assemble waterfall. Memory is bounded: session store LRU capped at 50, 20 snapshots per session, 50 trash entries per session.
• client/: registers a "Context" tab in conversation.view; every operation round-trips through fetch('/ctm') with responses validated by ctmResponseSchema; refresh is triggered reactively via useSession. A "pending" badge distinguishes queued-but-unlogged edits from applied ones.

Wire protocol

POST /ctm; the body is an op-discriminated union (JSON), and every request carries a sessionId:

op	extra fields
getState	—
replace	segmentId, content (UI allows replacing only the initial system prompt and non-system-injected segments; queued for logging when apply for real is on)
delete	segmentId
rollback	turnIndex
restore	snapshotId
reset	—
undo	—
override	segmentId, value (string | null)
setRealtime	enabled

Response: { ok: true, state: CtmState } | { ok: false, error: string }.

Every op may additionally carry an optional expectedVersion (the version of the last state the client applied): the host compares it before any side effect and rejects mismatches with a stale_version error notice (optimistic concurrency against multi-client / stale-page races).

Known limitation: undoing a rollback or a delete involving tool pairs restores the removed content as user messages (the first item replaces the placeholder node, the rest append to the tail) — an append-only log cannot re-add assistant/tool roles. This is the same role-demotion scheme as assistant edits.

The bundled client does not currently send expectedVersion; the host check is available to callers that supply it, not a guarantee for every UI edit. The transcript view belongs to the host and may still show shadowed messages. Compatibility with a newer DeepSeek Harness revision should be checked against the host APIs used by this plugin.

Install / uninstall

# Install from GitHub (pinning a tag is safer; on first install pnpm will ask you
# to add the package to allowBuilds in the profile's pnpm-workspace.yaml — git
# installs pull source only, and the package's prepare script builds it at install time)
dsh plugin --profile <name> add github:ac0033/dsh-ctm#v1.0.0
dsh plugin --profile <name> remove dsh-ctm

add automatically writes the package into the profile's dependencies + dsh.profile.bundles (because it declares dsh.bundle) — no manual cordis.patch.yml edits; remove cleans up the dependency, the bundle layer and node_modules together.

Local development

pnpm install
pnpm build            # produces dsh/index.js (host) + dsh/client.js (client)

Publishing

• Run pnpm build before publishing (e.g. a "prepublishOnly": "pnpm build" script); community users then receive the prebuilt dsh/index.js + dsh/client.js with zero build steps.
• Zero runtime dependencies: zod is inlined into both bundles; react resolves from the shell's module table.
• When moving to your own scope, update both name in package.json and the name: row in cordis.patch.yml.

License

MIT © YuanLumen