|
|
@@ -8,30 +8,32 @@ English | [中文](2026-09-05-workspace-files-service.zh.md)
|
|
|
|
|
|
The Web client needs to look at files inside a session's workspace from a browser that may not be on the Host machine: a file the agent produced, the path a `read` tool row names, later a file tree and previews of files that are neither small nor text. The one endpoint that read a workspace file over the wire lived on the Session Controller as `workspace-file.ts`, beside session lifecycle it had nothing to do with. It returned a whole file under one total byte cap, so a large log could not be looked at even in part and a binary could not be looked at at all; it had no `stat`, no listing, and no change signal, so a preview could not learn that the agent had rewritten the file without re-reading it; and its result named the file by a Host `url`, a spelling nothing on the Client used as an address.
|
|
|
|
|
|
-Two constraints frame any answer. Reads through `ctx.fs` are deliberately unconfined — the sandboxing backend fences writes and edits only and says so — so a web-facing read endpoint must own every fence itself, and the fences must survive a symlink that leaves the workspace, which a string-prefix test cannot see. And `dsh-fs` exposed one raw-byte read, `readBytes(target, signal, maxBytes)`, which refuses any file longer than its cap: correct for an image the model ingests whole, useless for one window of a large file.
|
|
|
+Two constraints frame the service. File reads through `ctx.fs` use the Session's composed filesystem backend, whose read authority may extend outside the workspace, while directory-tree and change-feed consumers are workspace-rooted. The service preserves the backend's read decisions for regular files while enforcing file-kind and bounded-buffer checks; `list` and `changes` retain workspace containment. And `dsh-fs` exposed one raw-byte read, `readBytes(target, signal, maxBytes)`, which refuses any file longer than its cap: correct for an image the model ingests whole, useless for one window of a large file.
|
|
|
|
|
|
## Decision
|
|
|
|
|
|
-`packages/api/workspace-files` (`@deepseek-ai/dsh-api-workspace-files`) owns the Host `ctx.workspaceFiles` service, the `workspaceFiles` Remote namespace, and the Client `file` provider that turns `stat` and `changes` into live metadata for the [resource model](2026-09-05-client-resource-model.md); [dual-face packaging](2026-09-07-workspace-files-dual-face-package.md) governs their package organization. Every method confines itself to the workspace root the sandbox policy resolves for the addressed session, names files by their absolute path in the filesystem's execution world, and pages or windows content so that no method ever buffers a whole file. The byte window rides on a new `dsh-fs` seam, `FileSystem.readByteRange`, implemented by every provider. The Session Controller carries no workspace-file code.
|
|
|
+`packages/api/workspace-files` (`@deepseek-ai/dsh-api-workspace-files`) owns the Host `ctx.workspaceFiles` service, the `workspaceFiles` Remote namespace, and the Client `file` provider that turns `stat` and `changes` into live metadata for the [resource model](2026-09-05-client-resource-model.md); [dual-face packaging](2026-09-07-workspace-files-dual-face-package.md) governs their package organization. File methods resolve relative paths from the workspace root but inherit the Session filesystem backend's read authority; `list` and `changes` remain workspace-scoped. The [workspace file read authority](2026-09-09-workspace-file-read-authority.md) owns this split and its security consequences. Results name files by their absolute path in the filesystem's execution world, and content is bounded by page, byte window, or complete-file cap. The byte window rides on a new `dsh-fs` seam, `FileSystem.readByteRange`, implemented by every provider. The Session Controller carries no workspace-file code.
|
|
|
|
|
|
### Package topology
|
|
|
|
|
|
-[dual-face packaging](2026-09-07-workspace-files-dual-face-package.md) supersedes this note's choice of separate Host and Client packages; the file service, authorization, paging, and change-feed decisions here remain in force. Host and Client compile in separate leaf configurations, share wire types, and the Client does not import the Host runtime entry.
|
|
|
+[dual-face packaging](2026-09-07-workspace-files-dual-face-package.md) supersedes this note's choice of separate Host and Client packages; the file service, paging, and change-feed decisions here remain in force. The [workspace file read authority](2026-09-09-workspace-file-read-authority.md) supersedes the original workspace-containment choice for file methods. Host and Client compile in separate leaf configurations, share wire types, and the Client does not import the Host runtime entry.
|
|
|
|
|
|
| Face | Package | Files | Depends on |
|
|
|
|---|---|---|---|
|
|
|
| Host | `api/workspace-files/tsconfig.host.json` | `src/index.ts` (`WorkspaceFiles`, `Config`, gates, pager), `src/changes.ts` (`WorkspaceChangeFeed`), `src/types.ts` (wire types, error codes) | `dsh-fs`, `dsh-sandbox-policy`, `dsh-typert-protocol`, `dsh-agent`, `dsh-session` |
|
|
|
| Client | `api/workspace-files/tsconfig.client.json` | `src/client/index.ts` (plugin body), `provider.ts`, `change-feed.ts`, `remote.ts`, `types.ts`, and shared `src/types.ts` | `dsh-api-gateway/client`, `dsh-api-session-controller/client`, `dsh-client-resources`, `dsh-util-workspace-path`, `dsh-typert-protocol`, and the package's generated `./remote` |
|
|
|
|
|
|
-`api/remotes` and both root aggregates reference the matching Host/Client leaf. The package exports `.`, `./client`, `./types`, `./typert`, and `./remote`, with one `workspace-files` web-app row supplying both faces. The Client plugin injects `['resources', 'remote', 'remote.workspaceFiles', 'sessions']`; the resource model takes result types directly from the protocol package, and the text preview owns the Sidebar parameter declaration, so the Client compilation graph has no reverse dependency on Remote assembly or Sidebar UI.
|
|
|
+`api/remotes` and both root aggregates reference the matching Host/Client leaf. The package exports `.`, `./client`, `./types`, `./typert`, and `./remote`, with one `workspace-files` web-app row supplying both faces. The Client plugin injects `['resources', 'remote', 'remote.workspaceFiles']`; the resource model takes result types directly from the protocol package, and the text preview owns the Sidebar parameter declaration, so the Client compilation graph has no reverse dependency on Remote assembly or Sidebar UI.
|
|
|
|
|
|
### The `workspaceFiles` Remote namespace
|
|
|
|
|
|
-Every Host method takes the target `Agent` first, resolved by the Gateway from the Session identity on the wire, so a Client calls `remote.workspaceFiles.stat(sessionId, path, signal)` and never names a root. The five signatures, as `src/index.ts` declares them:
|
|
|
+Every Host method takes the target `Agent` first, resolved by the Gateway from the Session identity on the wire, so a Client calls `remote.workspaceFiles.stat(sessionId, path, signal)` and never names a root. The seven signatures, as `src/index.ts` declares them:
|
|
|
|
|
|
```ts ignore-check
|
|
|
@Remote async read(agent: Agent, path: string, range: WorkspaceFileRange, signal: AbortSignal): Promise<WorkspaceFileText>
|
|
|
@Remote async readBytes(agent: Agent, path: string, range: WorkspaceByteRange, signal: AbortSignal): Promise<WorkspaceFileBytes>
|
|
|
+@Remote async readAll(agent: Agent, path: string, signal: AbortSignal): Promise<WorkspaceFileBytes>
|
|
|
+@Remote async readRelated(agent: Agent, path: string, relativePath: string, signal: AbortSignal): Promise<WorkspaceFileBytes>
|
|
|
@Remote async stat(agent: Agent, path: string, signal: AbortSignal): Promise<WorkspaceFileStat>
|
|
|
@Remote async list(agent: Agent, path: string, signal: AbortSignal): Promise<WorkspaceDirectoryListing>
|
|
|
@Remote({ mode: 'stream' }) changes(agent: Agent, signal: AbortSignal): AsyncIterable<WorkspaceFileWatchFrame>
|
|
|
@@ -40,25 +42,26 @@ Every Host method takes the target `Agent` first, resolved by the Gateway from t
|
|
|
- **`stat`** returns `WorkspaceFileStat { absolutePath, version, bytes? }`: the file's identity, its opaque freshness token, and its size when the backend reports one. It accepts a regular file only.
|
|
|
- **`read`** returns one window of lines, `WorkspaceFileText = WorkspaceFileStat & { offset, text, lines, eof }`; `lines` counts the page's lines, so a page holding one empty line (`text: ''`, `lines: 1`) and a page past the end (`lines: 0`) read differently. `range.offset` is the 1-based first line and defaults to 1; `range.limit` is the largest number of lines and defaults to `maxLines`, which it may not exceed. Lines end at `\n` and a final `\n` terminates the last line rather than opening an empty one; `text` joins the page's lines with `\n` and carries no terminator; `eof` is true when the page includes the last line, and an offset past the end returns an empty page with `eof` true. The pager walks `streamText`, counts the lines before the window without keeping them, admits each in-window segment against `maxBytes` before buffering it, and returns at the first character past the window, so a file of any size costs one page of memory. The `version` and `bytes` on a page are the stat's, taken before the stream.
|
|
|
- **`readBytes`** returns one window of raw bytes, `WorkspaceFileBytes = WorkspaceFileStat & { offset, data, eof }`. `range.offset` is the 0-based first byte and defaults to 0; `range.length` is the largest byte count and defaults to `maxBytes`, which it may not exceed. `data` is base64, shorter than `length` where the file ends and empty at or past it; `eof` is true when the window includes the last byte. Nothing is decoded and nothing is refused as binary. `read` pages by lines and never by bytes; a byte window is `readBytes`.
|
|
|
+- **`readAll` and `readRelated`** return complete `WorkspaceFileBytes` under `maxFileBytes`. `readRelated` resolves a relative filesystem path from the base file's directory; the Host applies the same regular-file checks and backend read authority to both files. [Document Preview](2026-09-08-document-preview-operations.md) owns their loading and address semantics.
|
|
|
- **`list`** returns `WorkspaceDirectoryListing { path, entries, truncated }`: the listed directory as a workspace path relative to the root (empty for the root), its direct children in the backend's stable name order as `{ name, type, size? }`, and whether `maxEntries` cut the list. `type` is `file`, `directory`, or `other`; a symlink child reports the type of what it points to and a dangling one is `other`, while opening such a child still fails the link gate below. Dotfiles are listed; nothing is filtered.
|
|
|
- **`changes`** yields `WorkspaceFileWatchFrame`: `{ kind: 'ready' }` after the observation queue is registered and the workspace root resolves, followed by `{ kind: 'change', change }`. The `WorkspaceFileChange` payload is `{ absolutePath, version }` for a present file or `{ absolutePath, absent: true }` for one observed gone. Its source is `fs/observed` inside the workspace root, never an OS watcher. Observations after the first pull are queued, including during root resolution; cancellation or plugin disposal ends the generation.
|
|
|
|
|
|
### Paths on the wire
|
|
|
|
|
|
-Two path vocabularies leave the service, and each method uses exactly one. `read`, `readBytes`, `stat`, and `changes` name a file by `absolutePath`: its absolute path in the filesystem's execution world, symlinks resolved (`ctx.fs.processPath(target)`), so the Client provider matches a change frame to an open address by absolute path: the Client sends the address's path unchanged to the Host and binds the follower only to a successful `stat.absolutePath`, without reading a Session summary's cwd. `list` speaks workspace paths — the same syntax its `path` argument accepts, absolute or relative to the root — because its consumer is a tree rooted there. The field is called `absolutePath` and not `url` because it is not a resource address; the address grammar belongs to `dsh-util-workspace-path` and is described with the resource model. Input paths to `read`, `readBytes`, `stat`, and `list` are absolute or relative to the session's workspace root, never to the backend's own cwd.
|
|
|
+Two path vocabularies leave the service, and each method uses exactly one. `read`, `readBytes`, `readAll`, `readRelated`, `stat`, and `changes` name a file by `absolutePath`: its absolute path in the filesystem's execution world, symlinks resolved (`ctx.fs.processPath(target)`), so the Client provider matches a change frame to an open address by absolute path: the Client sends the address's path unchanged to the Host and binds the follower only to a successful `stat.absolutePath`, without reading a Session summary's cwd. `list` speaks workspace paths — the same syntax its `path` argument accepts, absolute or relative to the root — because its consumer is a tree rooted there. The field is called `absolutePath` and not `url` because it is not a resource address; the address grammar belongs to `dsh-util-workspace-path` and is described with the resource model. Input paths to `read`, `readBytes`, `readAll`, `readRelated`, `stat`, and `list` are absolute or relative to the session's workspace root, never to the backend's own cwd.
|
|
|
|
|
|
`version` is an opaque string a consumer compares for equality and never parses: the local backend derives it from device, inode, size, and nanosecond mtime and ctime, so a rewrite that leaves the content identical still changes it. `offset` means a line on `read` and a byte on `readBytes`; the two units never mix, and `eof` on either means the window reached the file's end.
|
|
|
|
|
|
-### The four gates
|
|
|
+### File checks and workspace containment
|
|
|
|
|
|
-Every `read`, `readBytes`, `stat`, and `list` passes four gates in order, and the constraints are the service's own because the filesystem does not confine reads. The path is inspected before containment is decided, so a caller learns whether an outside path exists and what kind it is before `outside-workspace` refuses it; that is accepted because the caller is the Session's own owner, who can already read the Host through the Agent.
|
|
|
+`read`, `readBytes`, `readAll`, `readRelated`, and `stat` share regular-file checks and then rely on the filesystem backend's read authority. `list` shares path inspection but also checks workspace containment, while `changes` filters observations to the workspace root. The service applies the following checks:
|
|
|
|
|
|
1. **The path itself.** `lstat` inspects the path before anything follows it: a missing path is `not-found`, and a symlink — wherever it points, including back inside the workspace — is `not-regular-file` (kind `symlink`) for the file methods and `not-directory` for `list`. An empty path is a `gateway/bad-request`.
|
|
|
-2. **Containment.** The path resolves to a target and `ctx.fs.contains(root, target)` decides, where `root` is `sandboxPolicy.resolve({ session }).workspaceRoot` resolved the same way (the session's cwd, falling back to the policy's configured root). A `..` traversal or an absolute path outside the root is `outside-workspace`. A string-prefix comparison is never used: `resolve` realpaths, so a prefix test cannot see a link that leaves the root.
|
|
|
-3. **The caps.** A page or window above `maxBytes`, or a `read` asking for more than `maxLines`, is refused, never shortened, because a silently cut page reads as the whole page; a listing above `maxEntries` is cut and says so.
|
|
|
+2. **Workspace containment for `list`.** The directory resolves to a target and `ctx.fs.contains(root, target)` decides, where `root` is `sandboxPolicy.resolve({ session }).workspaceRoot` resolved the same way. A `..` traversal or an absolute directory outside the root is `outside-workspace`. `changes` applies the same backend containment predicate to observed targets.
|
|
|
+3. **The caps.** A page or window above `maxBytes`, or a `read` asking for more than `maxLines`, is refused, never shortened, because a silently cut page reads as the whole page; a listing above `maxEntries` is cut and says so. Complete and related-file reads are refused above `maxFileBytes`.
|
|
|
4. **Text.** For `read` only: content that is not UTF-8 up to the end of the page, a NUL byte in the backend's 8 KiB opening sample, or a NUL byte anywhere in the page is `not-text`; bytes past the page are not inspected.
|
|
|
|
|
|
-After the gates the file methods `stat` the target once more, because the file may have gone or changed kind between the inspection and the read: a vanished file is `not-found` and a replaced one `not-regular-file` with the new kind. The gate order has one visible consequence: an entry outside the root whose type already disqualifies it reports its kind, not its position.
|
|
|
+After path inspection the file methods `stat` the resolved target once more, because the file may have gone or changed kind before the read: a vanished file is `not-found` and a replaced one `not-regular-file` with the new kind. For `list`, an outside entry whose type already disqualifies it reports its kind before its position.
|
|
|
|
|
|
### Failures
|
|
|
|
|
|
@@ -67,20 +70,20 @@ Each failure is one `RemoteError` code with typed details, declared beside the t
|
|
|
| Code | When | Details |
|
|
|
|---|---|---|
|
|
|
| `workspace-file/not-found` | no entry at the path, or the file vanished after the gates | `{ path }` |
|
|
|
-| `workspace-file/outside-workspace` | the resolved target is not inside the workspace root | `{ path }` |
|
|
|
-| `workspace-file/too-large` | a page's text or a requested byte window exceeds `maxBytes` | `{ path, limit }` |
|
|
|
+| `workspace-file/outside-workspace` | a `list` target is not inside the workspace root | `{ path }` |
|
|
|
+| `workspace-file/too-large` | a page's text or byte window exceeds `maxBytes`, or a complete read exceeds `maxFileBytes` | `{ path, limit }` |
|
|
|
| `workspace-file/not-text` | invalid UTF-8 up to the page's end, or a NUL byte in the sample or the page (`read` only) | `{ path }` |
|
|
|
-| `workspace-file/not-regular-file` | `read`, `readBytes`, or `stat` on something that is not a regular file | `{ path, kind: 'directory' \| 'symlink' \| 'other' }` |
|
|
|
+| `workspace-file/not-regular-file` | `read`, `readBytes`, `readAll`, `readRelated`, or `stat` on something that is not a regular file | `{ path, kind: 'directory' \| 'symlink' \| 'other' }` |
|
|
|
| `workspace-file/not-directory` | `list` on something that is not a directory | `{ path, kind: 'file' \| 'symlink' \| 'other' }` |
|
|
|
| `workspace-file/unsupported-address` | Client-minted: a resource address this provider cannot serve | `{ address }` |
|
|
|
-| `workspace-file/unknown-workspace` | Client-minted: an `absolute` address with no current Session | `{ address }` |
|
|
|
+| `workspace-file/unknown-workspace` | Client-minted: an `absolute` address, which carries no Session | `{ address }` |
|
|
|
| `gateway/bad-request` | an empty path, or an `offset`, `limit`, or `length` that is not an integer in range | `{}` |
|
|
|
|
|
|
The set is append-only: a code may be added, and none is renamed or removed, because consumers branch on these strings across the wire.
|
|
|
|
|
|
### Configuration
|
|
|
|
|
|
-Three fields, all validated positive integers changeable from `cordis.yml`, and no other tunables: `maxBytes` (default 2,097,152, 2 MiB) is the inclusive cap on one page's text and on one byte window; `maxLines` (default 5,000) is the default and largest page in lines; `maxEntries` (default 2,000) is the cap on returned directory entries. The file itself has no size cap: a caller pages or windows through it.
|
|
|
+Four fields, all validated positive integers changeable from `cordis.yml`, and no other tunables: `maxBytes` (default 2,097,152, 2 MiB) is the inclusive cap on one page's text and on one byte window; `maxLines` (default 5,000) is the default and largest page in lines; `maxEntries` (default 2,000) is the cap on returned directory entries; `maxFileBytes` (default 33,554,432, 32 MiB) caps complete and related-file reads. Paged and windowed reads impose no whole-file size cap.
|
|
|
|
|
|
### The `readByteRange` seam in `dsh-fs`
|
|
|
|
|
|
@@ -96,27 +99,27 @@ It returns the bytes at `[offset, offset + length)`, shorter when the file ends
|
|
|
|
|
|
### The Client `file` provider
|
|
|
|
|
|
-The Client export registers one `ResourceProvider<'file'>` into `ctx.resources` for the plugin's lifetime and declares `ResourceProtocolMap.file`. The text-preview package registers this package's exported `WorkspaceFileParams` as `SidebarRightResourceParamsMap.file`.
|
|
|
+The Client export registers one `ResourceProvider<'file'>` into `ctx.resources` for the plugin's lifetime and declares `ResourceProtocolMap.file`. The Document Preview package registers this package's exported `WorkspaceFileParams` as `SidebarRightResourceParamsMap.file`.
|
|
|
|
|
|
-- **The value is metadata**, `WorkspaceFileResource { absolutePath, version, bytes?, changed }`; content never rides the stream because content can be arbitrarily large and a stream is for pushing change, not payload. A consumer reads pages with `read` (or windows with `readBytes`) and uses `version` and `changed` to know when they are stale.
|
|
|
-- **The address names the file; its scope selects the Session.** A `session` address's relative path reaches the Host unchanged for resolution and containment against that Session's workspace root; Client cwd is not a prerequisite. An `absolute` address reads through the current Session, failing with `workspace-file/unknown-workspace` when none is current. Unsupported grammar yields `workspace-file/unsupported-address`. These two Client errors end the stream and make reload a no-op.
|
|
|
-- **The frames.** The first frame is a `stat` (`changed: false`) or its failure as an `ok: false` frame; the provider throws and catches nothing, because the Remote face never rejects and a throw inside a provider stream is a programming error left to surface. A Host write carrying a version the value does not hold yields `changed: true` with the byte count kept and no stat; a frame carrying the held version is dropped. A reported disappearance stats again — still there is fresh metadata flagged `changed`, gone is a `not-found` frame with the previous value left for display. `reload(address)` stats again and yields `changed: false`. The follow is on the address, not the file: after a failed stat the stream continues, so the agent creating the file, or a reload, brings the resource live. Aborting the signal ends the stream silently.
|
|
|
+- **The value is metadata**, `WorkspaceFileStat { absolutePath, version, bytes? }`; content never rides the stream because content can be arbitrarily large and a stream is for pushing change, not payload. A consumer reads pages with `read` (or windows with `readBytes`) and compares versions to know when they are stale; freshness and refresh belong to each consumer, not the shared observation.
|
|
|
+- **The address names the file; its scope selects the Session.** A `session` address's relative or absolute path reaches the Host unchanged; the workspace root supplies the base for a relative path, and the Session filesystem backend decides read access. Client cwd is not a prerequisite. An `absolute` address has no Session and fails with `workspace-file/unknown-workspace`; no current or tab Session is borrowed. Unsupported grammar yields `workspace-file/unsupported-address`. These two Client errors end the stream.
|
|
|
+- **The frames.** The first frame is a `stat` or its failure as an `ok: false` frame; the provider throws and catches nothing, because the Remote face never rejects and a throw inside a provider stream is a programming error left to surface. A Host write carrying a version the value does not hold yields that version with the byte count kept and no stat; a frame carrying the held version is dropped. A reported disappearance stats again — still there is fresh metadata, gone is a `not-found` frame with the previous value left for display. The follow is on the address, not the file: after a failed stat the stream continues, so the agent creating the file brings the resource live. Aborting the signal ends the stream silently.
|
|
|
- **One `changes` subscription per Session.** The first follower opens `remote.$stream`, the last release disposes it, and successor streams and plugin teardown await pending closes. The Client starts its first `stat` only after accepting Host `ready`; sending a local WebSocket request is not Host acknowledgement. A follower registers by address, queues changes before its path is known, then filters queued and live frames by the successful stat's `absolutePath`, normalizing backslashes to slashes. Any Session write can trigger a re-stat before the first successful binding. Gateway supervision reconnects carrier loss; Host end or terminal failure ends followers and retains their last metadata until reopened.
|
|
|
- **Navigation parameters.** `SidebarRightResourceParamsMap.file` is `WorkspaceFileParams { line?: number }`, a 1-based line to reveal. A line travels as a navigation parameter and not as part of the address, because the file is one piece of content whether it opens at the top or at line 400.
|
|
|
|
|
|
### Related notes
|
|
|
|
|
|
-The [resource model](2026-09-05-client-resource-model.md) owns `ctx.resources`, `useResource`, the `dsh-resource://<type>/…` address grammar, and the reasoning for one resource per address; the [text preview and file tree](../feature/2026-09-05-sidebar-text-preview-and-file-tree.md) are the shipped consumers of `read`, `list`, and the `file` provider; the [right Sidebar docking infrastructure](../feature/2026-09-04-right-sidebar-docking-infrastructure.md) is the surface they open into; [workspace file links](../feature/2026-07-31-web-workspace-file-links.md) is where serving files over HTTP was rejected. Anyone extending this system reaches the same five methods through `remote.workspaceFiles` and the same `file` resource through `useResource<'file'>`; the wire types are published as `@deepseek-ai/dsh-api-workspace-files/types`.
|
|
|
+The [resource model](2026-09-05-client-resource-model.md) owns `ctx.resources`, `useResource`, the `dsh-resource://<type>/…` address grammar, and the reasoning for one resource per address; the [text preview and file tree](../feature/2026-09-05-sidebar-text-preview-and-file-tree.md) are the shipped consumers of `read`, `list`, and the `file` provider; the [right Sidebar docking infrastructure](../feature/2026-09-04-right-sidebar-docking-infrastructure.md) is the surface they open into; [workspace file links](../feature/2026-07-31-web-workspace-file-links.md) is where serving files over HTTP was rejected. Anyone extending this system reaches the same seven methods through `remote.workspaceFiles` and the same `file` resource through `useResource<'file'>`; the wire types are published as `@deepseek-ai/dsh-api-workspace-files/types`. The [workspace file read authority](2026-09-09-workspace-file-read-authority.md) owns Host read access and the HTML security trade-off; [Document Preview](2026-09-08-document-preview-operations.md) owns content loading and per-tab freshness.
|
|
|
|
|
|
## Alternatives considered
|
|
|
|
|
|
-**Keeping the workspace file endpoint on the Session Controller.** The first form: one `read` under a total byte cap, registered as a sub-plugin of the Session Controller because that is where the wire entry already was. Rejected because a Workspace File service is its own capability — reading, statting, listing, and observing files inside a workspace root — and everything that queries workspace files belongs to it, while the Session Controller's concern is session lifecycle. The move also let the service grow to five methods without the Controller's file gaining a second purpose.
|
|
|
+**Keeping the workspace file endpoint on the Session Controller.** The first form: one `read` under a total byte cap, registered as a sub-plugin of the Session Controller because that is where the wire entry already was. Rejected because a Workspace File service is its own capability — reading and statting files plus listing and observing the workspace — and those queries belong together, while the Session Controller's concern is session lifecycle. The move also let the service grow to five methods without the Controller's file gaining a second purpose.
|
|
|
|
|
|
**A dual-face package with reverse UI dependencies.** The split-package choice followed two project-reference cycles after `api/remotes` referenced the Client leaf: the resource model imported Remote assembly for result types, and the file provider imported Sidebar UI for its parameter map. TypeScript rejected these cycles with `TS6202`. [dual-face packaging](2026-09-07-workspace-files-dual-face-package.md) supersedes that split: result types come directly from the protocol package, and Sidebar parameter registration belongs to the text preview; both root aggregates retain explicit compiler entries.
|
|
|
|
|
|
**Serving workspace files over HTTP.** Already rejected by [workspace file links](../feature/2026-07-31-web-workspace-file-links.md) on origin grounds and not revisited: `read` and `readBytes` carry plain text and base64 over the authenticated Remote carrier, so no document is served, no URL is minted, and no origin question arises.
|
|
|
|
|
|
-**Log-reachable authorization for the read.** The one precedent that sends file content over the wire, command attachments, authorizes only files that appear in the session log. Enough for produced files, but a typed path or a directory tree could never open. Path containment inside the workspace root was chosen, with the endpoint owning the constraints the filesystem's unconfined reads do not, and containment decided by `fs.contains` on resolved targets so a symlink cannot escape it.
|
|
|
+**Log-reachable or workspace-contained authorization for file reads.** The one precedent that sends file content over the wire, command attachments, authorizes only files that appear in the session log. That excludes typed paths, while workspace containment excludes readable files elsewhere on the Session backend. The [workspace file read authority](2026-09-09-workspace-file-read-authority.md) instead makes the backend's read decision authoritative and keeps containment only for workspace-shaped operations.
|
|
|
|
|
|
**Whole-file read and slice for the byte window.** The interim form of `readBytes` read the file from its start to the window's end through `readBytes(target, signal, offset + length)` and sliced. It cannot read a window of a file longer than that end — the seam refuses such a file as too large — so no window could ever report `eof: false`, which contradicts the reason the method exists. Rejected in favour of the `readByteRange` seam, whose bound is the window.
|
|
|
|
|
|
@@ -124,28 +127,25 @@ The [resource model](2026-09-05-client-resource-model.md) owns `ctx.resources`,
|
|
|
|
|
|
**A default `readByteRange` in the `FileSystem` base class.** A non-abstract default over `readBytes` would have spared the test doubles a method but could only be implemented by reading the whole file up to the window's end, the very behaviour rejected above, or by passing an unbounded cap. Abstract, with every provider and double implementing it.
|
|
|
|
|
|
-**String-prefix containment.** Comparing resolved path strings against the root is simpler than `fs.contains`, but `resolve` realpaths, so a symlink that leaves the root resolves to a path outside it while a prefix test on the unresolved spelling passes; and a prefix test on the resolved spelling still needs the backend's notion of "same file". The filesystem decides containment.
|
|
|
+**String-prefix containment for workspace operations.** Comparing resolved path strings against the root is simpler than `fs.contains`, but `resolve` realpaths, so a symlink that leaves the root resolves to a path outside it while a prefix test on the unresolved spelling passes; and a prefix test on the resolved spelling still needs the backend's notion of "same file". The filesystem decides containment for `list` and `changes`.
|
|
|
|
|
|
## Consequences
|
|
|
|
|
|
- Workspace file access belongs to the Host/Client faces of `api/workspace-files`; the Session Controller carries neither implementation, and compiler and runtime entries stay separate.
|
|
|
-- A file of any size opens: text by line page, anything by byte window, each costing one page or window of memory on the Host and never a whole file; the cost is that a consumer assembles pages itself and that a single line above `maxBytes` has no page at all, because pages are cut by lines.
|
|
|
+- A file of any size opens: text by line page, anything by byte window, each costing one page or window of memory on the Host; complete reads instead enforce `maxFileBytes`; the cost is that a consumer assembles pages itself and that a single line above `maxBytes` has no page at all, because pages are cut by lines.
|
|
|
- Every filesystem provider now offers a windowed raw read. `fs-e2b` pays for it by transferring the skipped prefix, since its SDK cannot seek; `fs-local` seeks.
|
|
|
-- Paths on the wire are canonical: `absolutePath` and change frames spell a file with symlinks resolved. An address built from another spelling of the same file — a workspace root reached through a symlink — opens and stats it, but its change frames never match, so `changed` stays false until a reload.
|
|
|
+- Paths on the wire are canonical: `absolutePath` and change frames spell a file with symlinks resolved. A follower binds to successful `stat.absolutePath`, so another spelling of the same file — a workspace root reached through a symlink — uses that canonical change key.
|
|
|
- Change frames report the agent's own operations only. A file edited by the user's editor, a shell, or a subprocess raises no frame; an agent merely reading a file that something else changed does raise one, because the read observes a new version.
|
|
|
-- The gate order reports kind before position, a page's `version` may be one write behind its content, and a stalled `changes` consumer grows Host memory, because a generation's queue is unbounded; each is a known trade-off recorded in the package README.
|
|
|
+- File-kind inspection precedes backend reads, and `list` reports kind before an outside position. A page's `version` may be one write behind its content, and a stalled `changes` consumer grows Host memory because a generation's queue is unbounded; each is a known trade-off recorded in the package README.
|
|
|
- The `file` resource pushes change, not content, so a preview learns a file moved on without a payload and reads the pages it wants; a failed open keeps following the address, so the agent creating the file brings the tab live without user action.
|
|
|
-- `readBytes` has no shipped consumer yet: it is the wire form the image and binary previews build on.
|
|
|
+- `readBytes` has no shipped consumer yet; Document Preview uses `readAll` for complete-file formats.
|
|
|
|
|
|
## Testing
|
|
|
|
|
|
-Host specs in `packages/api/workspace-files/tests` exercise the paged read (whole file, nested path, empty file, multi-byte UTF-8, the line window's edges, defaults and refused limits, carriage returns kept), the byte window (defaults, a middle window with more following, tail windows exact and short, past-end and empty files, NUL and invalid UTF-8 round-tripping through base64, version parity with `stat`, the cap as `too-large`, bad ranges, a window of a file far above the cap, and `eof` inferred without a size), `stat`, `list` with truncation, symlink children, and `not-directory`, the `changes` stream driven by `fs/observed` and filtered by root, and every gate and code against a real local backend, because a fake filesystem would let a prefix test pass the symlink case the gate exists to catch. Client specs in `packages/api/workspace-files/tests` cover the provider's frames (opening stat, failure frames, writes without content, disappearance, reload, recovery, abort), the change feed (one stream per session, fan-out by normalized path, queued frames, ending on signal or Host close), the unsupported-address cases, and registration and disposal with the fiber. `fs/fs`, `fs-local`, and `fs-e2b` specs pin `readByteRange`'s range semantics — a middle window, a tail shorter than asked, past-end and zero-length windows, errors, aborts, and the e2b cancel — and `dsh-util-workspace-path` specs pin the file-address grammar. The connection fixture serves `stat`, paged `read`, `list`, and an opt-in `changes` frame for the web e2e suite.
|
|
|
+Host specs in `packages/api/workspace-files/tests` exercise the paged read (whole file, nested path, empty file, multi-byte UTF-8, the line window's edges, defaults and refused limits, carriage returns kept), the byte window (defaults, a middle window with more following, tail windows exact and short, past-end and empty files, NUL and invalid UTF-8 round-tripping through base64, version parity with `stat`, the cap as `too-large`, bad ranges, a window of a file far above the cap, and `eof` inferred without a size), `stat`, outside-workspace reads and backend refusals, `list` with containment, truncation, symlink children, and `not-directory`, and the `changes` stream driven by `fs/observed` and filtered by root. Client specs in `packages/api/workspace-files/tests` cover the provider's frames (opening stat, failure frames, writes without content, disappearance, recovery, abort), the change feed (one stream per session, fan-out by normalized path, queued frames, ending on signal or Host close), the unsupported-address cases, and registration and disposal with the fiber. `fs/fs`, `fs-local`, and `fs-e2b` specs pin `readByteRange`'s range semantics — a middle window, a tail shorter than asked, past-end and zero-length windows, errors, aborts, and the e2b cancel — and `dsh-util-workspace-path` specs pin the file-address grammar. `readAll` and `readRelated` specs cover complete-read caps, outside base and related paths, and Host backend authorization. The connection fixture serves `stat`, paged `read`, `list`, and an opt-in `changes` frame for the web e2e suite.
|
|
|
|
|
|
## Deferred
|
|
|
|
|
|
-- A web e2e chain through the Sidebar: open a file, have the agent write it, see `changed`, reload.
|
|
|
-- Aliasing a follower under the Host's canonical spelling once the first `stat` reveals it, so a symlinked workspace root still receives change frames.
|
|
|
- A bound on a `changes` generation's queue.
|
|
|
- The shipped consumer of `readBytes` (image and binary previews) and any write, search, or media route; the service is read-only.
|
|
|
- Scopes other than `session` in the file address; the grammar leaves room, the provider serves one.
|
|
|
-- Reload delivery per record: today `reload` re-stats every follower of the file's absolute path in the session, so two records naming one file — a `session` and an `absolute` address, or two readers with different addresses — clear each other's `changed` flag.
|
Yichen Jiang