---

dsh-fovea adapts pi-fovea into a native DeepSeek Harness plugin and bundle. It compiles a repository into a typed, weighted graph, turns a question or change set into an interest field, diffuses relevance through that graph, and spends a bounded context budget where it matters.

The implementation composes with Harness rather than building a parallel host: DSH owns tools, policy, lifecycle, logs, filesystem access, subprocesses, and optional spills. Fovea adds four repository-intelligence tools, continuous structural drift detection, a slash command, and a runtime skill.

What it provides

Surface	Purpose
fovea_sketch	Survey feature basins, routes, hubs, and extraction coverage.
fovea_focus	Center on a symbol, route, concept, or file and reveal its semantic neighborhood.
fovea_dwell	Widen the current focus without repeating disclosed periphery.
fovea_impact	Rank the blast radius and review order of files, symbols, worktree changes, or a base-ref diff.
/fovea	Human-facing status, reset, sketch, focus, dwell, and impact commands when ctx.commands is present.
fovea skill	Model/user guidance registered when ctx.skills is present.
Continuous sync	Quiet baselining plus logged steering when repository drift is structurally surprising.

Every model tool returns one canonical JSON value:

{ text: string, tokens: number, details: Record<string, JSONValue> }

Harness renders text to the model while Code Mode and other programmatic callers retain tokens and details. Fovea does not replace native grep or exact file reads: use it to decide where and why, then inspect the selected source precisely.

Requirements

• Node.js ^22.19.0 || >=24.0.0
• pnpm 11.20.0 for this checkout
• DeepSeek Harness services pinned to 0.1.0-rc.6
• Cordis ^4.0.1
• Git for tracked-file discovery, base-ref impact, and co-change history (plain directories still work)

@ast-grep/cli is a runtime dependency. Executable resolution is: FOVEA_AST_GREP, then the packaged CLI, then a bare ast-grep on the active subprocess provider's PATH. A remote subprocess provider cannot execute the host package's binary, so install ast-grep in that execution world or set FOVEA_AST_GREP to its provider-visible path.

Install from this checkout

The safe local installer builds this package, records any prior profile dependency, asks the pinned DSH CLI to add the checkout link, and verifies the composed dsh-fovea row. It never starts or restarts DSH.

# Defaults to the web profile
pnpm run install:local

# Select another profile
pnpm run install:local -- --profile tui

# Reuse already-built artifacts
pnpm run install:local -- --skip-build

# Use a non-default DSH home
DSH_HOME=/path/to/home pnpm run install:local

Reload or restart the selected running profile after installation. Verify composition directly with:

pnpm dlx @deepseek-ai/dsh@0.1.0-rc.6 --profile web --dump-config

Uninstall only the link owned by this checkout and restore the exact previous dependency, if any:

pnpm run uninstall:local
pnpm run uninstall:local -- --profile tui

After an npm release exists, the equivalent profile operation is expected to be:

pnpm dlx @deepseek-ai/dsh@0.1.0-rc.6 plugin --profile web add dsh-fovea

Model tool reference

All roots come from the calling agent's session cwd; no Fovea tool accepts an arbitrary filesystem root. Tool max_tokens values are clamped to 256–16000.

fovea_sketch(max_tokens?)

Use once near the start of work in an unfamiliar repository. It emphasizes production anchors and structural hubs while collapsing tests and distant regions.

fovea_focus(query, max_tokens?, fresh?, path?, language?, kind?)

query may be a symbol, route, concept, or repository-relative file. Optional filters narrow by path, language, or graph-node kind. Set fresh to reset disclosure even when the nucleus matches the previous focus.

Supported kinds are function, method, class, interface, type, field, decl, file, and anchor.

fovea_dwell(factor?, max_tokens?)

Widen the current agent-scoped focus. The default diffusion multiplier is 2; values below 1.2 are raised to 1.2, and diffusion time is capped internally.

fovea_impact(files?, symbols?, include_uncommitted?, base?, max_tokens?)

Seed a hypothetical or real change and rank consequences with causal paths. With no explicit seeds it includes uncommitted work; supplying base computes a base...HEAD comparison unless include_uncommitted is also requested.

A productive sequence is:

1. fovea_sketch for an unfamiliar repository.
2. fovea_focus on the most concrete task noun.
3. Native reads/grep on the suggested windows.
4. fovea_dwell only if the first neighborhood is too narrow.
5. fovea_impact before finishing a cross-file change.

Human command

When the profile provides ctx.commands, dsh-fovea registers:

/fovea status
/fovea reset
/fovea sketch
/fovea focus <query>
/fovea dwell [factor]
/fovea impact [files...]

/fovea <query> is also a focus shortcut. Command output uses the configured default budget.

Configuration

The bundle patch inserts one row with id dsh-fovea. Override it in the selected profile's $DSH_HOME/profiles/<profile>/cordis.patch.yml (or a later --patch layer):

- id: dsh-fovea
  config:
    defaultBudget: 768
    toolTimeoutMs: 120000
    sync:
      mode: enabled
      scope: session
      budget: 512
      steerThreshold: 0.15
      pushFocus: true
      ackClean: false
      warmMutations: true

Key	Default	Valid values
defaultBudget	512	integer 256–16000
toolTimeoutMs	120000	integer 1000–2147483647
sync.mode	enabled	enabled, hidden, or disabled
sync.scope	session	session or repository
sync.budget	512	integer 128–8192
sync.steerThreshold	0.15	finite number 0.02–8
sync.pushFocus	true	boolean
sync.ackClean	false	boolean — tiny "nothing new" ack after a clean structural check
sync.warmMutations	true	boolean

Unknown configuration keys fail plugin loading. enabled emits plugin notice messages; hidden uses plugin instructions messages for the model; disabled removes sync and mutation-attribution hooks while keeping explicit tools, command, and skill. The deployment-level FOVEA_TURN_SYNC=off (also 0 or false) escape hatch always forces disabled mode.

Advanced environment controls

These are deployment-level tuning controls read when modules load:

Variable	Default	Range / meaning
FOVEA_AST_GREP	packaged CLI	Execution-world ast-grep path/name override
FOVEA_TURN_SYNC	unset	off, 0, or false disables continuous sync
FOVEA_MAX_FILES	8000	100–100000 discovered files
FOVEA_MAX_FILE_BYTES	1048576	65536–67108864 bytes per source
FOVEA_MAX_ROOTS	2	1–32 resident workspace graphs
FOVEA_MAX_AGENT_SESSIONS	32	1–4096 resident agent/session attention states
FOVEA_SPAWN_CONCURRENCY	3	1–32 concurrent subprocess stages
FOVEA_IO_CONCURRENCY	32	4–512 concurrent provider I/O operations
FOVEA_MAX_SUBMODULE_DEPTH	4	1–16 nested repository depth
FOVEA_AST_GREP_CHUNK	160	32–2048 files per parser chunk
FOVEA_PROBE_TTL_MS	1200	200–60000 send-path Git probe interval
FOVEA_MEMORY_HALF_LIFE_HOURS	48	1–8760 surprise-memory half-life
FOVEA_COCHANGE_HALF_LIFE_DAYS	30	1–3650 co-change half-life
FOVEA_WALK_GAP_MS	4000	500–300000 plain-root relist gap
FOVEA_SWEEP_GAP_MS	20000	2000–600000 plain-root full sweep gap

Invalid integer environment values fall back to the listed default.

Continuous sync

The lifecycle integration is active unless sync.mode is disabled:

1. agent/session-start begins indexing asynchronously and establishes a quiet content-hash baseline.
2. Successful tools named write or edit with a string file_path receive best-effort before/after hash attribution without replacing those tools.
3. tools/result can warm graph refresh and impact math after such mutations.
4. agent/pre-step performs a deferred drift check and appends model context only when a prepared red verdict exists.
5. agent/turn-stopping performs the full correctness check and calls agent.steer(...) only for a red verdict.
6. With sync.ackClean: true, a clean structural check outside silent-baseline paths emits one tiny "nothing new" ack — appended like a deferred update so it can never restart an idle agent.
7. Branch checkout generations re-baseline quietly; charged cascades cool over time instead of echoing every turn.

Shell side effects, external editors, and other mutation paths remain unattributed. Provenance distinguishes current-session, other-session, mixed, and unattributed transitions when exact hash chains permit it. Current DSH provenance is process-memory scoped, bounded to 2,048 records, and pruned after seven days.

All injected context uses DSH message sources under plugin dsh-fovea, so Harness owns transcript durability and presentation.

The math behind the graph, heat kernel, literal bridges, co-change seeding, inferred basins, discovery mode, and the turn-sync surprise gate is documented in docs/heat-diffusion.md.

Architecture and adaptation boundary

flowchart LR
  Agent[DSH Agent] -->|tool call| Tools[ctx.tools / ToolRuntime]
  Agent -->|session-start, pre-step, turn-stopping| Sync[Continuous sync]
  Tools --> Adapter[DshFoveaRuntime]
  Sync --> Adapter
  Adapter --> FS[ctx.fs]
  Adapter --> Proc[ctx.subprocess]
  Adapter --> Spill[optional ctx.spillStore]
  Adapter --> Core[Reusable Fovea core]
  Core --> Shared[(Graph + facts by FsTarget targetKey)]
  Core --> Scoped[(Focus + disclosure + sync memory by workspace and agent)]
  Sync -->|red verdict: agent.steer| Agent

Layer from pi-fovea	dsh-fovea strategy
Graph types, joins, basins, extraction facts, heat diffusion, ranking, rendering	Reused with minimal algorithmic change.
Filesystem discovery, ast-grep, Git, caches, provenance, overflow	Retained behind the FoveaRuntime capability seam and DSH providers.
Focus, dwell, disclosure, sync baselines, surprise memory	Agent/workspace-scoped rather than root-global.
Pi entry point, event names, TUI widgets/settings, hidden-message API, grep takeover	Not reused; replaced by Cordis plugin loading, canonical DSH tools, agent events, command, skill, and system-prompt guidance.

There is intentionally no browser client plugin: dsh-fovea contributes server/runtime behavior and appears through existing Harness tool, command, skill, and transcript surfaces.

Execution-world rules

• Repository paths resolve from the calling agent's session cwd through ctx.fs.
• Provider FsTarget.targetKey identifies shared graph/fact state; ctx.fs.processPath(...) crosses only into the matching subprocess provider.
• Git and ast-grep run through ctx.subprocess, with bounded output, timeout, cancellation, and process-tree ownership.
• DSH cache/provenance entries are bounded in-memory data: 32 MiB per entry and 128 MiB total. They do not survive a DSH process restart.
• The standalone Node adapter uses private temporary-disk cache files instead.
• Complete overflow lists use optional ctx.spillStore only for top-level tool calls that carry session/call ownership. Command and sync rendering stays bounded without creating unowned spills.

Indexing, coverage, and limits

Fovea keeps the graph complete only within its configured indexing envelope; every rendered answer remains token-bounded.

• Default discovery stops at 8,000 supported files.
• Sources over 1 MiB, generated/minified bundles, unreadable files, and parser-failed chunks are omitted or degraded and reported in details and /fovea status.
• Ignored directories include .git, node_modules, dist, vendor, virtual environments, build outputs, coverage, target, and common dependency caches.
• Nested repositories/submodules are progressively enrolled when observed work touches them instead of being traversed eagerly.
• Plain non-Git roots use provider directory walks. Git roots additionally gain tracked/untracked discovery, base diffs, and recency-decayed co-change history.
• Repository-owned .fovea/rules.json is loaded automatically and extends built-in anchor/file-route rules. Treat repository rule files as trusted project configuration.

The implemented language tiers are:

• Full symbol/call extraction: TypeScript, TSX, JavaScript, Python, Go, and Rust.
• Outline-symbol extraction: Elixir, Ruby, C, C++, Java, Kotlin, Lua, PHP, Swift, Scala, Haskell, and Bash.
• Literal/config joins: YAML, JSON, TOML, env, Terraform/HCL, Markdown, and route conventions including OpenAPI-style paths.

Framework and language coverage is tiered; an empty result is not proof of absence when extraction reports degraded coverage.

Repository rule example

{
  "rules": [
    {
      "id": "custom-http-route",
      "langs": ["TypeScript"],
      "pattern": "$R.endpoint($P, $$$H)",
      "methods": "^endpoint$",
      "kind": "route"
    }
  ],
  "fileRoutes": [
    {
      "id": "custom-file-route",
      "re": "(?:^|/)endpoints/(.+)\\.ts$",
      "verbs": "suffix",
      "kind": "route"
    }
  ]
}

Malformed or invalid entries are ignored and built-in rules remain active.

Programmatic core API

The dsh-fovea/core export supports local Node consumers through the same runtime seam:

import {
  NodeFoveaRuntime,
  sketch,
  withFoveaRuntime,
} from 'dsh-fovea/core'

const runtime = new NodeFoveaRuntime(process.cwd(), { scopeKey: 'example' })
const result = await withFoveaRuntime(runtime, () =>
  sketch(runtime.processRoot, 512),
)
console.log(result.text)

Implementations embedding the engine can provide their own FoveaRuntime; operations must always execute inside withFoveaRuntime(...).

Development and verification

pnpm install --frozen-lockfile
pnpm run typecheck
pnpm run build
pnpm run test
pnpm run verify

# Complete release gate
pnpm run check

# Dev probe: build stats + anchor coverage for one or more repos
pnpm tsx scripts/probe.ts <repo...>

The tests cover core math/rendering/configuration, workspace/agent isolation, real DSH fs and subprocess execution, canonical tool values, optional command/skill registration, lifecycle steering, mutation provenance, and spill behavior. The verifier imports built entry points and checks bundle, exports, artifacts, and Pi-host dependency hygiene.

Pinned baseline: DeepSeek Harness 0.1.0-rc.6. Harness is in developer preview, so compatibility is reviewed release by release.

Relationship to the other projects

• pi-fovea is the original implementation and source of the graph, diffusion, rendering, and repository-intelligence design.
• dsh-fabric established the out-of-tree DSH bundle and installer conventions followed here.
• DeepSeek Harness owns the agent loop, session log, tools, policy, execution providers, and browser shell with which this plugin composes.

License and acknowledgments

MIT © Tom Nguyen. See LICENSE and THIRD_PARTY_NOTICES.md.

Built for DeepSeek Harness, adapted from pi-fovea, with Fovea's original direction inspired by a request from Alp for better repository intelligence.