Files
deepseek-harness/packages/fs
mektpoy b0ad792e6b fix(web): keep dedicated previews and the read-card lang domain
The shared code-language table must not claim a suffix a dedicated viewer
declares, and the Host read card must keep the `lang` values it already
persisted.

- Drop `csv` from the shared table: Code registers before Spreadsheet, so
  the earlier body would take `.csv` and the browser snapshot gate fails.
- Add `readLangHintForPath`, the read card's legacy projection over the
  shared table: the 43 pre-unification suffixes keep their old short ids
  byte for byte, new suffixes use the canonical id.
- Add an ownership regression test over the full preview registry that
  turns red when `csv` returns, plus byte-level and alias-normalized tests
  for the read projection.
2026-09-21 19:14:08 +08:00
..

description, kind
description kind
The filesystem package group: the ctx.fs provider contract, local and sandbox-enforcing backends, the read-before-edit policy plugin, and the model-facing file and search tools. package-group

packages/fs

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Summary

The fs/ group gives agents durable, policy-governed access to files: the ctx.fs service contract in fs/, the host-filesystem and sandbox-enforcing backends in fs-local/ and fs-sandbox/, the read-before-edit policy in fs-observation-policy/, and the model-facing tools in tool-fs/ (read, read_image, write, edit) and tool-fs-search/ (glob, grep). A deployment mounts one backend, loads the policy for freshness-guarded mutations, and registers the tool packages the model should see; backends swap without touching the tools or the policy. File I/O takes no timeout by design: a deadline would kill work the OS still finishes, so cancellation is a best-effort signal at syscall boundaries.

Table of Contents


Packages

Seven packages play the filesystem roles; the subsystem reference owns the exhaustive contracts and the error taxonomy.

Package Role ctx key
fs/ ctx.fs service contract: execution-world paths, bounded text I/O, and atomic mutations with an optional version guard ctx.fs
fs-local/ Host-filesystem backend: reads, writes, and edits real files on the local machine registers on ctx.fs
fs-sandbox/ Sandbox-enforcing backend: fences writes and edits by the per-call sandbox mode while reads pass through registers on ctx.fs
fs-observation-policy/ Read-before-edit policy: records observed presence or absence and guards write/edit through the fs/* events fs/* listeners
tool-fs/ Model-facing read, read_image, write, and edit tools plus their executor registers on ctx.tools
tool-fs-search/ Model-facing glob and grep discovery tools backed by the packaged ripgrep binary registers on ctx.tools
tool-str-replace-editor/ Standalone str_replace_editor tool: view, create, str_replace, and insert over ctx.fs registers on ctx.tools

The policy is a plugin, not a service the tools inject: removing it leaves the bare provider's unconditional mutation behavior instead of breaking the tools. The mode fence in fs-sandbox and the read-before-edit gate compose. tool-fs-search deliberately does not extend the provider contract — search is a process-backed ripgrep workflow, so filesystem backends stay free of a universal search API.


Start with the subsystem reference for the shared vocabulary and error taxonomy, then the decisions that shaped the family.

Dev Note

Working context for maintainers — click to expand

None.