dsh-fff

FFF (Fast File Finder) tools for DeepSeek Harness. Registers fffind (fuzzy file-path search / glob) and ffgrep (content grep) as model tools, backed by a resident @ff-labs/fff-node index whose root follows the current session workspace.

Install

dsh plugin --profile <name> add ./dsh-fff
# restart dsh web for the bundle layer to activate

This links the bundle into the profile's node_modules, appends it to dsh.profile.bundles, and inserts the fff-tools plugin row. Remove with dsh plugin --profile <name> remove dsh-fff.

The bundle declares @ff-labs/fff-node as a dependency, so pnpm installs the platform native binary (@ff-labs/fff-bin-<platform>) alongside.

How it works

The native fff SDK cannot load inside the harness process, so the plugin spawns a resident helper (lib/fff-server.mjs) that owns one FileFinder hot index and answers line-delimited JSON on stdio — the same spawn-a-native-binary pattern as @deepseek-ai/dsh-tool-fs-search.

Each tool call resolves the calling session's workspace from exec.agent.session.header.cwd. When it differs from the helper's current index root, the plugin asks the helper to reindex (and waits for the new scan, ~50–100 ms) before querying. This is what the MCP-injected fff-mcp could not do: its index root was fixed by the process cwd's git-root probe, so it searched the wrong tree for every session in another workspace.

Tools

Tool	Purpose	Parameters
fffind	Fuzzy file-path search (or glob)	query (req), pageSize, useGlob
ffgrep	Content grep (plain/regex/fuzzy)	query (req), mode, pageSize, beforeContext, afterContext, classifyDefinitions

Both return { base, totalMatched, totalFiles, items }; output.render presents the matches as model text.

Configuration

The fff-tools row accepts these keys (all optional):

Key	Default	Description
basePath	''	Fixed index root; empty resolves from the session workspace per call
scanTimeoutMs	30000	Wait budget for an index scan / reindex
toolCallTimeoutMs	30000	RPC timeout per tool call
serverPath	packaged copy	Absolute path to the helper script

Model Experience

Request context and condition

What the model sees

Two tool schemas (fffind, ffgrep) with descriptions that direct fuzzy/indexed search over the built-in ripgrep tools.

Token effect

Fixed: two tool definitions are always registered while the plugin is loaded; their descriptions are part of the assembled tool catalog.

KV Cache effect

The tool-catalog prefix is stable while the plugin is loaded; no per-request dynamic content is injected into the prompt.

Known Limitations and Deferred Work

• Concurrent sessions share one index root. The resident helper holds a single FileFinder; when two sessions in different workspaces interleave calls, each call reindexes to its own workspace (correct but pays the reindex cost on each switch). A per-session cache or the agent/session-start warm-up is future work.
• Native binary platform coverage is whatever @ff-labs/fff-node ships; an unsupported platform surfaces a clear tool error.
• No background file watcher (disableWatch: true): the index reflects the state at last reindex, not live filesystem changes. Reindex happens per workspace switch; within one workspace, files edited after indexing are picked up on the next reindex.