deer-flow/docs/ARCHITECTURE.md
Hyeonsang Cho 556975f284
fix(gateway): gate github_token and disable_clarification on internal callers (#5338)
* fix(gateway): gate github_token and disable_clarification on internal callers

`non_interactive` is honored only for internally-authenticated callers
because it strips `ask_clarification` from the lead-agent toolset. The two
sibling run-context keys reproduced that effect without the gate.

`merge_run_context_overrides` forwarded `_CONTEXT_RUNTIME_ONLY_KEYS`
regardless of `internal`, and `strip_internal_context_keys` scrubbed only
`_CONTEXT_INTERNAL_CALLER_KEYS` -- so any session or PAT caller could set
`disable_clarification` through `body.context`, or through the free-form
`body.config` that `build_run_config` copies verbatim. That is not a milder
flag than `non_interactive`: ClarificationMiddleware answers every
clarification -- `risk_confirmation` included -- with "proceed without
asking" instead of interrupting, and SandboxMiddleware reads the two keys as
the same non-interactive signal. `github_token` rode the same path into
`runtime.context`, where the bash tool exports it as `GH_TOKEN`/`GITHUB_TOKEN`,
and a copy smuggled through `body.config['configurable']` reached the
checkpoint store the context-only rule exists to avoid.

Both keys are produced server-side by the channel run policies, which reach
the Gateway over the internally-authenticated request channel, so gate them
the same way: forward them only when `internal=True`, and scrub the union
`_INTERNAL_ONLY_CONTEXT_KEYS` from both config sections for every other
caller. Destination stays an orthogonal axis -- `_CONTEXT_RUNTIME_ONLY_KEYS`
still land in `context` alone, never in checkpoint-persisted `configurable`.

Regression coverage in tests/test_gateway_services.py pins both smuggling
surfaces and replays the real start_run assembly order for a session caller
and for an internal one, so the GitHub channel keeps carrying its minted
token.

* docs(changelog): record the internal-only run-context key gate (#5338)

* docs(agents): keep the run-context note inside the AGENTS.md budgets

The AG002 inherited-chain check failed at this head. The new backend section
and the root scheduled-task sentence added 993 B to the root and backend
guidance both the sandbox and middlewares chains inherit, pushing sandbox 6 B
over the 98304 B hard limit and growing the middlewares chain, which main
already exceeds by 155 B. An already-over chain is only tolerated while it does
not grow, so the shared ancestors had to come back to their base size.

Condensed the new material and removed prose the root file was duplicating:

- The trust-boundary section keeps both gated surfaces, both helpers, the
  trust-vs-destination split, and the disable_clarification note in half the
  space.
- The root scheduled-task bullet names all three internal-only keys and both
  smuggling surfaces while staying under its previous size.
- Dropped the root `scheduler.recursion_limit` bullet, which restated
  backend/AGENTS.md:18 almost verbatim; its one unique fact (a YAML edit needs
  no Gateway restart) moved to that bullet.
- Deduplicated the nginx routing sentence, which already deferred to the
  backend routing table, and tightened the waiver note's sequencing tail.

Root and backend guidance now sit 50 B under their combined base size, so the
sandbox chain returns to 97310 B and the middlewares chain no longer grows.
Every file stays under its AG001 soft budget.
2026-09-11 11:33:52 +08:00

196 lines
11 KiB
Markdown

# DeerFlow Architecture
This document is the **top-level architecture overview** for DeerFlow. It explains the
"big picture" — how the services, layers, and cross-cutting subsystems fit together — and
points to the module-level guides that own the depth:
- Backend depth → [`backend/AGENTS.md`](../backend/AGENTS.md) and [`backend/docs/ARCHITECTURE.md`](../backend/docs/ARCHITECTURE.md)
- Frontend depth → [`frontend/AGENTS.md`](../frontend/AGENTS.md)
DeerFlow 2.0 is a ground-up rewrite of the original Deep Research framework (see
[`README.md`](../README.md)); it shares no code with v1.
---
## 1. What DeerFlow Is
DeerFlow (**D**eep **E**xploration and **E**fficient **R**esearch **Flow**) is an
open-source **super-agent harness** built on LangGraph. A single "lead agent" orchestrates
**sub-agents**, **persistent memory**, **sandboxed code execution**, and **extensible
skills/tools** — all isolated per conversation thread. The frontend is a Next.js chat UI;
external IM platforms (Feishu, Slack, Telegram, Discord, DingTalk) bridge into the *same*
agent through the Gateway.
---
## 2. Service Topology
A single `make dev` (or Docker stack) runs four cooperating services; Nginx is the only
public entry point.
| Service | Port | Role |
| --------------- | ------ | ------------------------------------------------------------------- |
| **Nginx** | `2026` | Unified reverse proxy — open this in the browser |
| **Gateway API** | `8001` | FastAPI REST API + embedded LangGraph-compatible agent runtime |
| **Frontend** | `3000` | Next.js web interface |
| **Provisioner** | `8002` | Optional — only when sandbox is in provisioner/K8s mode |
**Nginx routing** (the key entry-point contract):
- `/api/langgraph/*` → Gateway's LangGraph-compatible runtime (rewritten to native `/api/*`)
- `/api/*` (other) → Gateway REST routers
- `/*` (non-API) → Frontend
This lets standard LangGraph SDK clients talk to DeerFlow without a separate LangGraph
server. Both compose files publish nginx as `"${BIND_HOST:-127.0.0.1}:${PORT:-2026}:2026"`
**loopback by default**; the Gateway's `8001` is never published. Any new published port
must carry an explicit bind address (`backend/tests/test_compose_default_bind_host.py`
pins this for every service in both compose files).
---
## 3. Backend: Harness / App Split
The backend is two layers with a **strict one-way dependency**:
- **Harness** (`backend/packages/harness/deerflow/`, import prefix `deerflow.*`) — the
publishable agent framework: orchestration, tools, sandbox, models, MCP, skills, memory,
config. Everything needed to *build and run* agents.
- **App** (`backend/app/`, import prefix `app.*`) — unpublished application code: the
FastAPI Gateway and IM channel integrations.
**Rule**: App imports `deerflow`, but `deerflow` never imports `app`. This boundary is
enforced in CI by `backend/tests/test_harness_boundary.py`. A thin third package,
`deerflow-extension-api` (`backend/packages/extension-api/`), defines the host-independent
extension contract that plugins implement.
There is also an **embedded Python client** (`deerflow.client.DeerFlowClient`) used by
scheduled tasks and tests to drive the same run lifecycle programmatically.
### Agent runtime path
All run modes (local `make dev`, Docker, prod) execute the agent through the Gateway via
`RunManager` + `run_agent()` + `StreamBridge` (`packages/harness/deerflow/runtime/`). The
agent is assembled by `make_lead_agent()` and wrapped in a **middleware chain** that runs
before the model call:
1. ThreadDataMiddleware — set up `workspace`/`uploads`/`outputs` paths
2. UploadsMiddleware — inject uploaded file list
3. SandboxMiddleware — acquire sandbox
4. SummarizationMiddleware — context reduction (if enabled)
5. TitleMiddleware — auto-generate conversation title
6. TodoListMiddleware — task tracking (plan mode)
7. ViewImageMiddleware — vision-model image handling
8. ClarificationMiddleware — handle `ask_clarification`
SSE streaming carries both per-chunk messages and bounded `values` snapshots; with
`stream_subgraphs`, delegated subagents publish namespaced SSE events (`values|<ns>`,
LangGraph Platform style) rather than impersonating root frames, so SDK clients don't lose
the parent thread view.
### State, tools, sandbox
- **`ThreadState`** extends LangGraph's `AgentState` with `sandbox`, `artifacts`,
`thread_data`, `title`, `todos`, `viewed_images`. Each thread gets isolated data dirs
under `backend/.deer-flow/threads/{thread_id}/`.
- **Tools** come from three sources, merged by `get_available_tools()`: built-ins
(`present_files`, `ask_clarification`, `view_image`, `review_skill_package`), configured
tools (`bash`, `read_file`, `write_file`, `str_replace`, `ls`, web search/fetch), and
MCP tools.
- **Sandbox** is an abstract `SandboxProvider` with `LocalSandboxProvider` (dev, direct
execution) and `AioSandboxProvider` (Docker, production isolation). Agent code executes
inside sandbox boundaries with virtual path mapping (`/mnt/user-data/...`).
---
## 4. Frontend: Stateful Chat over LangGraph SDK
Next.js 16 / React 19 / TypeScript / Tailwind v4. Stack: LangGraph SDK (`@langchain/langgraph-sdk`)
for orchestration + streaming, TanStack Query for server state. Requires Node 22+ and pnpm
10.26.2+.
The frontend is a **stateful chat app**: users create **threads** (conversations), send
messages, set thread-scoped `/goal` completion conditions, and receive streamed responses.
The backend may produce **artifacts** (files/code), **todos**, and goal-state updates.
**Source layout** (`frontend/src/`):
- `app/` — App Router routes: `/workspace/chats/[thread_id]` (authenticated chat),
`/workspace/agents/[agent_name]` (custom agents), `/showcase/[thread_id]` (allowlisted
public read-only demos), `/api/*` route handlers, `(auth)/{login,setup,auth/callback}`.
- `core/` — the business-logic heart. Domains: `threads/` (creation, streaming, state),
`api/` (LangGraph client singleton), `agents/`, `auth/`, `artifacts/`, `channels/`,
`integrations/`, `memory/`, `skills/`, `mcp/`, `models/`, `tasks/`, `todos/`, `tools/`,
`workspace-changes/`, `config/`, `i18n/` (en-US, zh-CN), and more.
- `components/``workspace/` (chat), `landing/`, `docs/`; `ui/` and `ai-elements/` are
registry-generated (Shadcn / Vercel AI SDK) and must not be hand-edited.
- `hooks/`, `lib/` (`cn()`), `content/` (MDX), `styles/`.
**Streaming data flow**: `core/threads/` subscribes to the LangGraph run stream via the
`core/api/` client singleton, normalizes SSE events (messages, `values`, `task_*`,
artifact deltas) into TanStack-Query-managed thread state that components render. Subtask
progress rides root-namespace `task_*` custom events (the web frontend does not request
subgraph streaming).
By default the frontend connects through nginx: `NEXT_PUBLIC_LANGGRAPH_BASE_URL=/api/langgraph`
and `NEXT_PUBLIC_BACKEND_BASE_URL=` (empty). Leave these unset for the standard `make dev`
/ Docker flow.
---
## 5. Cross-Cutting Subsystems
These span both layers and require reading multiple files to understand:
- **Config system** — lives at repo root: `config.yaml` (models, tools, sandbox,
summarization, scheduler) and `extensions_config.json` (MCP servers + skills). Both are
gitignored, generated from the `*.example.*` templates, and editable at runtime via the
Gateway API. Operator-controlled third-party `plugins:` live only in `config.yaml`
(never the API-writable `extensions_config.json`) because that list causes code import.
- **Skills** — `skills/public/` (committed) and `skills/custom/` (gitignored); managed
integration packs are global at `.deer-flow/integrations/skills/{provider}/`. Skills are
discovered/loaded lazily by the harness; `skills/public/skill-reviewer/` is a read-only
quality reviewer using the harness `review_skill_package` tool.
- **Sub-agents** — background delegation via `SubagentExecutor` (server-side `execution_id`)
correlated to provider `tool_call_id` for `ToolMessage`/SSE/lifecycle/persistence. Scheduled
tasks reuse the *same* Gateway run lifecycle (scheduler decides *when*, not *how*).
- **Scheduled tasks** — workspace page `/workspace/scheduled-tasks` + a background scheduler
gated by `config.yaml → scheduler.enabled`; non-interactive runs drop `ask_clarification`
and client-supplied `non_interactive` (see the run-context trust boundary in §6).
- **Long-running MCP** — a durable `McpTaskService` (leased rows, DB as source of truth)
keeps remote task IDs/polling out of the agent loop.
- **Version sources** — a release version must match in `backend/pyproject.toml`,
`frontend/package.json`, and `deploy/helm/deer-flow/Chart.yaml` (`version` + `appVersion`);
pushing a `v*` tag triggers CI that runs `scripts/verify_versions.sh` and blocks all
publishing on drift. See [`RELEASING.md`](../RELEASING.md).
---
## 6. Security & Isolation Model
- **Thread isolation**: each conversation has separate data dirs; uploads are validated
against path traversal and staged as `.upload-*.part` before atomic replace.
- **Sandbox isolation**: production should use the Docker `AioSandboxProvider`; local
sandbox is dev-only direct execution.
- **MCP isolation**: each MCP server runs in its own process with runtime env-var
resolution; servers toggle independently.
- **Run-context trust boundary**: run context reaches the agent from two client-writable
surfaces — `body.context` and the free-form `body.config` — so every server-produced key
is gated on both. `non_interactive`, `disable_clarification`, and `github_token` are
honored only for internally-authenticated callers (the scheduler and IM/webhook channel
policies) and scrubbed from a non-internal caller's config; identity and sandbox
lifecycle fields are cleared unconditionally and restamped from auth state.
- **Loopback-by-default ingress**: nginx is the only published surface; the Gateway's `8001`
is container-internal and never published. A bare `"${PORT}:2026"` bind (0.0.0.0) is
rejected by convention and CI. See the Security Notice in [`README.md`](../README.md) before
any non-loopback deployment.
---
## 7. Where to Go Next
- System topology & component depth → [`backend/docs/ARCHITECTURE.md`](../backend/docs/ARCHITECTURE.md)
- Backend commands, TDD, harness/app boundary, config reload → [`backend/AGENTS.md`](../backend/AGENTS.md)
- Frontend commands, source layout, streaming data flow → [`frontend/AGENTS.md`](../frontend/AGENTS.md)
- Setup & install → [`Install.md`](../Install.md), [`CONTRIBUTING.md`](../CONTRIBUTING.md)
- Release process → [`RELEASING.md`](../RELEASING.md)
- User-facing features & deployment sizing → [`README.md`](../README.md)