LLeMbas-CLI/harness/filesystem.md

The file system a session works in

Spec 3.0.0. Two worlds, one harness. A chat (a conversation on the server) works in the server's file system: a tree kept by the instance, which may hold repositories mounted from a forge. An agent session (LLeMbas CLI, Desktop's agent, or an agent chat the web UI runs on a linked device) works in its working directory on its own machine. Neither sees the other's files. What the two share is this contract: how paths read, what kinds of node there are, how access is said, what an error says, how a listing and a search look, and how instruction files are collected. The tools are the same names and schemas on both sides (tools/*.json, sessions); where a tool exists on one side only, it says so there.

The conformance areas are fs_access (the view and its errors) and instructions (the instruction chain). An agent session's local disk is the special case of one node kind less (no mounts) and one access level for the whole working directory, decided by the CLI's permission rules and modes (permission/) rather than by the table below.

Paths

• Absolute paths begin with /, the root of the tree: the organisation's root on the server, the file system's root on a device.
• Relative paths resolve against the session's start directory (its working directory).
• . and .. are resolved by their text, before anything is looked up; .. above / stays at /. Repeated / count as one, and a trailing / changes nothing. On the server there are no links: a path is what it says. On a device, a link is followed, and where the CLI's rules look at a path they look at where it really is (an AGENTS.md committed as a link to a file outside the project is not read).
• Every answer names a path in its absolute, resolved form, whatever the call gave.
• Names are case-sensitive, /-separated, and never empty, . or ...

Node kinds

Kind	What
dir	a directory of the tree
file	a file: bytes, with a content hash (SHA-256)
mount	a directory that is a repository on a forge, at one branch. Below it, every node is a dir or a file of that repository. Server only

A session has a boundary (what it may see at all: the root, a directory, one repository) and a start directory inside it. On a device the boundary is the project root (the directory the CLI's trust is given to) and the start directory is where the session started.

Access levels

Each path is at one of four levels for a session:

Level	Name	Read	Change	Commit
none	no access	no	no	no
ro	read-only	yes	no	no
stage	read/write, stage	yes	yes	no
commit	read/write, commit	yes	yes	yes

• Inside a mount, stage means a change goes into the session's working copy (kept by the instance) and stops there; commit means the session may also send it to the forge (commit, branch, pr, merge, tag, release). Outside mounts there is nothing to commit, and the two write levels mean the same: write.
• A grant names a path and a level, and covers everything below the path. The most specific grant wins: / at ro and /Notes at stage make /Notes/a.md writable and /b.md read-only; /Notes/Private at none takes that directory away again.
• A floor is a maximum level per path, set where the session cannot widen it (the data group's). The most specific floor entry applies; the level a session has is its grant, lowered to the floor.
• A path with no grant on it or above it is at none. Only what is at ro or above exists for the model. On a mount, the forge decides first: a level is never above what the user's own forge account may do there.
• The levels a session has are told to the model (prompts/blocks/workspace.md, {{view}}): every granted path with its level, so it knows the full paths it may use.

A granted path under a path that is not

The tree /AGENTS.md, /Dir1/, /Dir1/FILE1.txt, /Dir1/Dir3/, /Dir2/, with /AGENTS.md and /Dir1/Dir3/ granted and nothing else:

• The model sees /AGENTS.md and /Dir1/Dir3/, each by its full path, and everything below /Dir1/Dir3/.
• / and /Dir1 are passages: at none, with something granted below. A passage is denied for reading and writing alike: list /Dir1, read /Dir1/FILE1.txt, write /Dir1/new.txt and mkdir /Dir1/x all answer Access denied: … is not open to this session.
• A listing never reveals a sibling: nothing lists /Dir1, and a listing of a granted directory shows only its entries at ro or above.
• A path the session cannot see is answered by what the model already knows: by its nearest ancestor that is either visible or a passage. Under a visible directory it is No such file or directory; under a passage, Access denied. So /Dir2/b.md (hidden) and /Nope.md (missing) get the same answer here — both under the passage / — and a hidden entry under a granted directory reads exactly as a missing one.
• A search (glob, grep, search) rooted at a granted directory finds what is granted below it, however it is reached; one rooted at a passage is denied like a listing.
• An instruction file in a passage is not loaded (below).

One thing cannot be hidden, and the spec accepts it: under a directory the session may write, a name taken by an entry at none cannot be created. Making it answers Access denied for that path, which says the name is taken and nothing else — not its kind, its size or what is in it.

What each operation needs

Operation	Tools	Needs
look	list, read, glob, grep, search, show, python's files, skill_view, skills_list	ro
change	write, edit, mkdir, mv (the source and the target's directory), rm, python's save, skill_manage	stage
commit	commit, branch, pr, merge, tag, release	commit, inside a mount

A new path takes the level of the most specific grant above it. mv between a mount and the rest of the tree, or between two mounts, is refused; rm of a mount itself is refused (a mount is removed by whoever mounted it, not by a session). rm on the server moves to the trash, restorable from the file explorer; inside a mount it stages the deletion.

Errors

A tool's error is its result (loop.json parallel). The texts, exactly, with {path} the resolved absolute path:

Case	Text
not visible (missing, or at none), and its nearest visible-or-passage ancestor is visible	No such file or directory: {path}
a passage; not visible with a passage as that ancestor; a name taken by an entry at none	Access denied: {path} is not open to this session.
a change at ro	Read-only: {path} can be read in this session but not changed.
a commit at stage	Not committed: this session may change {path} but not commit it; the change stays staged.
a commit outside every mount	Nothing to commit: {path} is not in a repository.
a directory where a file was meant	Is a directory: {path}
a file where a directory was meant	Not a directory: {path}
mv's target, or a file mkdir was asked to make	Already exists: {path}
a tool whose requires is not met at the time of the call	the tool's unavailable text

A device's own errors (a file too large, a binary file, a protected path) are the CLI's and stay as they are; the ones above it says the same way.

A listing

list and a directory given to read: one entry per line, directories (and mounts) with a trailing /, then — in a chat — a mount marked [mount] and an entry the session can read but not change, in a directory it can, marked [read-only]. Directories first, then by name.

A search

search(query, path?, limit?) ranks passages by meaning (embeddings) and by words (full-text) fused by rank, then keeps only what the session's view allows — after scoring, so a hidden file changes neither the results nor how many there are. A result is the passage's path and line range, then the passage:

/Notes/setup.md:12-30
<the passage>

grep is the exact counterpart (text or a pattern), over the same view.

Indexing, by tokens

What search reads is built when a file is written (a mount: its default branch, and again for the files a new commit changes). The index is keyed by content hash, so a file in many places, or unchanged across commits and branches, is embedded once; a rename or a move costs nothing.

Text is cut into pieces by tokens, not by characters: an embedder refuses input past its context (512 tokens is common), and dense text — another language than English, code, hashes — holds far more tokens per character than prose. A piece is at most 480 tokens (size; room for the embedder's own markers under 512) and repeats the last 64 tokens (overlap) of the one before it. The cut rules are the character splitter's (conformance/chunk.json) measured in tokens: the window is the longest stretch of at most size tokens; the cut is just after a paragraph break, else a line break, else a sentence's . , looked for in the window's last third (by characters), else at the window's end; the next piece begins at the start of the token overlap tokens before the cut. Pieces under 40 characters are dropped; a text that fits is one piece.

Tokens are counted with the embedder's own tokenizer where the server says how (llama.cpp's /tokenize, for one). Where it does not, a count of ceil(UTF-8 bytes / 2) stands in — an estimate, not a bound: it has not been measured against a real tokenizer. A piece the embedder still refuses for its length is split in two at the best cut and both are embedded; nothing is dropped. conformance/chunk_tokens.json fixes the rules with a stand-in tokenizer (a token is a run of non-whitespace), so both projects can be checked without an embedder.

Instruction files, stacked

Instruction files are collected from the boundary down to the start directory, outermost first: every directory on the way may contribute one, and all of them go to the model — the root's, then a section's, then a repository's. (Before 3.0.0 the CLI took only the nearest one.)

• The names, in order of preference within one directory: AGENTS.md, then CLAUDE.md. A directory contributes the first of them that is a file the session can read; never both.
• Only what the session can read is loaded. A file at none — in a passage, or taken away under a granted directory — is not loaded, and the walk goes on below it: the next directory down may still contribute. A file granted on its own (/AGENTS.md ticked while / is not) is loaded.
• A start directory outside the boundary is read as the boundary.
• On a device the boundary is the project root, a file counts only when it really is a file inside the project (a link to elsewhere is not read), and the CLI's global AGENTS.md comes before the chain, the instructions named in its configuration after it.
• Below the start directory, a file under a directory with its own instruction file hands the model that file the first time something under it is read, once per session (the CLI's "nearby instructions"), by the same reading rules.
• Each is given to the model under its path relative to the boundary.

conformance/instructions.json gives the cases, including the passage.

Skills

A skill is a directory with a SKILL.md (frontmatter name, description), and skills_list, skill_view and skill_manage are its meaning over files on both sides: the index in the prompt (prompts/blocks/skills.md), skill_view to load one, skill_manage to make or change one, which checks the frontmatter, the name and the size; edit works on the file too. In a chat, skills live in the tree (/skills/<name>/SKILL.md, and a skills repository mounted there); on a device they are local files, as before. Neither side syncs skills on its own.

Memory

Memory is records, not files, and the server keeps them for both sides: a chat's memory is its data group's partition, and a device logged in to an instance reads and writes the same records through the instance (acp.md, The HTTP API), for a session the web UI opened in that chat's data group, and for a session of its own in the group of the session's model. The memory tool is the same tool on both sides (tools/memory.json); what each offers of its targets is its narrow.