deer-flow/examples/deerflow-extension-workflows/README.md

Script workflows (Phase 3)

An opt-in packaged extension that runs inspectable JavaScript orchestration in the background. Scripts call full DeerFlow Agents through the public AgentRuns capability. A chat tool or authenticated plugin action returns a workflow run ID promptly; Script workflows shows the script, argument hashes, execution limits, progress, child conversation/run identities, and final result.

Versioned definitions, retained output snapshots, explicit same-process pause/resume, and authenticated human checkpoints support staged inspection reports. Agent success, script verdicts, tool permission approval and human output approval remain separate facts. Compatible workflows can be recovered explicitly after a single Gateway restart. No arbitrary JavaScript continuation serialization or hard monetary budget is provided.

Install and enable

Requires a POSIX Gateway (Linux/macOS), Python 3.12+, the public extension API 0.2.8, and a single Gateway process per storage file. Windows execution is unsupported. The package holds an exclusive process lock; another process using that same file fails service startup rather than recovering another worker's live workflows. Use only a trusted operator-installed package.

Pinned QuickJS 1.19.4 provides CPython 3.12 wheels for macOS universal2 and Linux x86_64. Python 3.13/3.14 and Linux arm64 installations build its source distribution: install a C compiler and matching Python development headers first (for example, Xcode Command Line Tools on macOS, or build-essential plus the matching python3-dev package on Debian/Ubuntu). Source-build compatibility depends on your Python/toolchain; use CPython 3.12 on a wheel-supported platform if the build fails. This also applies to backend development dependency installation and arm64 containers.

From the repository root:

make extension-install SOURCE="$(pwd)/examples/deerflow-extension-workflows"

Set the installed plugin's operator-owned config.yaml entry:

plugins:
  - name: workflows
    use: deerflow_extension_workflows:install
    enabled: true
    config:
      enabled: true
      storage_path: /absolute/deployment-owned/workflows.sqlite
      agents: [lead_agent]  # Add explicitly authorized existing Custom Agent names.
      concurrency: 2
      global_concurrency: 4
      max_calls: 16
      max_workflows: 4
      max_workflows_per_owner: 2
      timeout_seconds: 300
      admission_timeout_seconds: 10
      pause_timeout_seconds: 86400  # Separate bound for each human/pause wait, maximum 7 days.
      cpu_seconds: 5
      memory_bytes: 16777216

Find Script workflows in the workspace extension directory for the installation guide. Its catalog listing does not indicate installation or activation; the operator configuration above and Gateway runtime registration determine availability.

Restart Gateway. The namespace is community.workflows; the page is /workspace/extensions/community.workflows/runs. The UI and tools are disabled by default. agents restricts target selection in addition to normal host permissions; it does not grant access to otherwise unauthorized models, tools or Agents. Only supported host session/auth-disabled credentials supply a retained AgentRuns handle; PAT/internal/channel callers cannot acquire one.

Run an example

Open Script workflows, paste examples/checks.workflow.js, and enter:

{"product":"Synthetic sample","formula":["ingredient A"],"claims":["sample claim"]}

Click Launch workflow. An accepted launch shows its run ID immediately; if refreshing the list or details fails, use Retry inspection. Inspection retries do not launch another workflow. Resubmitting unchanged script/arguments retains the same request ID, including after a lost launch response; changing either creates a new launch identity. The example sequences evidence collection, fans out two checks, performs at most two review calls, and branches on a structured verdict. It returns findings for human review, never a product-pass or approval claim. This invokes your configured real Agents and can incur provider costs.

In chat, ask the lead to write an inspectable workflow script and launch it with launch_workflow, retaining a stable request_id. Host tool names are derived from the namespace. Use inspect_workflow on demand to inspect outcomes and cancel_workflow to request cancellation; do not ask the lead to poll continuously. The plugin page refreshes active progress every two seconds.

Script API

A script is an async function body, not a Node module. No imports, module loader, process, shell, filesystem, network, credentials, or Python callbacks are exposed. Frozen args is a JSON object.

const first = await agent({stepId:'first', agentRef:'lead_agent', task:args.task});
const checks = await parallel([
  () => agent({stepId:'a',agentRef:'lead_agent',task:{evidence:first.output}}),
  () => agent({stepId:'b',agentRef:'lead_agent',task:{evidence:first.output}})
]);
log('Two checks finished');
return checks.map(check => check.output);

agent() resolves to {output, threadId, runId, status: 'success', artifactVersion}. output is the last attributable non-tool assistant answer: parsed JSON if valid, otherwise text or content blocks. There is no provider-enforced structured output schema in this API; validate verdicts in the script before branching. Every Agent call must be awaited, including fan-out calls. Returning while child promises are outstanding fails the workflow and interrupts tracked children.

Agent task inputs allow 16,000 serialized JSON bytes, including wrapping fields and file references; step outputs allow 12,000. This leaves room to pass a saved output to the next Agent with a short task instruction. JSON escaping counts toward these limits. Larger material must use the file workflow described below.

parallel() takes lazy thunks and preserves order. The service, independently of JavaScript promises, bounds admitted children per workflow and globally. A rejected call rejects its promise; failures are not silently converted to null. Scripts may catch ordinary failures and use explicit bounded revisions with new step IDs. Limit faults, human-input waits, and uncertain admissions stop the supervisor even if script code catches their promise rejection.

Step IDs contain 1–80 ASCII letters, digits, underscores or hyphens and cannot repeat within a workflow. Attempts are currently always 1. task is JSON and becomes an ordinary human message on a distinct, stably named owned child thread. The host binds that thread's target Agent, checks current authorization on each operation, and uses its normal agent assembly, models, tools, skills, memory and checkpoints. The ledger records the requested agent reference and child IDs; it does not claim to record a per-run effective assembly fingerprint.

Saved versions, live resume and human review

Use Workflow name → Save workflow version, then select an exact saved version. The immutable version is the SHA-256 of the script; identical saves are idempotent. Definitions are owner-scoped (100 versions per owner). Launching the same saved version with new arguments requires a new request ID and records both argument and script hashes. Saved scripts never silently follow the latest version. Editing the script detaches it from the selected definition. Chat tools save_workflow and list_workflows provide the same library; launch_workflow accepts either script or definition: {name, version} with args and request_id.

const evidence = await agent({stepId:'evidence',agentRef:'lead_agent',task:args.product});
await humanCheckpoint({
  stepId:'confirm-evidence', sourceStepId:'evidence', artifactVersion:evidence.artifactVersion
});
await pause({stepId:'before-report'});
return await agent({stepId:'report',agentRef:'lead_agent',task:{evidence:evidence.output}});

Checkpoints must be awaited alone after all outstanding calls. They share the unique step-ID namespace; each attempt is 1 and has at most one decision. Up to max_calls checkpoints are allowed in addition to the Agent call limit. A pause retains the same isolated worker and its live JS variables. Resume this checkpoint continues there, reusing completed values without reading newer thread state or replaying earlier script code. It cannot retry a failed/cancelled workflow, answer a child's graph interrupt or change script/arguments. After restart use Recover workflow first, then resume or decide the retained checkpoint. An old resume request names its exact step/attempt and cannot release a later pause. Paused workers consume normal active workflow slots and memory; cancel unused waits. The execution wall budget is suspended while waiting; each wait has its own pause_timeout_seconds deadline (default 24 hours, maximum 7 days). CPU, call and log limits remain cumulative; worker CPU limits apply per worker incarnation. Expiry fails closed and never approves anything.

The host records an opaque durable declarative configuration revision: app configuration, extension configuration, and allowed Custom Agent config/SOUL. It rechecks this revision before each new child and when continuing a checkpoint; changes require a new workflow. Operator limits/allowlist changes also invalidate continuation. This is deliberately conservative (even unrelated declarative config changes invalidate), and not a full effective-assembly fingerprint: mutable memory, referenced Skill/tool file contents, remote provider state and external side effects are not attested. Completed results are historical snapshots, not a claim that rerunning against changed external data would produce the same result. Each new child still goes through ordinary current authorization and Agent assembly.

Review exact output displays the captured source-step output. Only then are Approve this version / Reject this version offered. The host decision action requires an authenticated browser session for the owner, exact checkpoint ID, attempt and server-derived output hash. Model tools, internal/PAT callers and auth-disabled sessions cannot approve. Auth-disabled deployments can run workflows and ordinary pauses, but must enable login to use human checkpoints. Approvals cannot be submitted through script messages; model-written “approved” has no effect. Matching duplicate decisions return the saved receipt without duplicate dispatch; a contradictory decision conflicts. Rejection stops downstream execution.

For files, use captureArtifact({stepId, sourceStepId, path}) after the source Agent completes. This stores independent bytes with SHA-256 and an immutable version, rather than approving a mutable path. Pass the capture step/version to humanCheckpoint. The browser reads that version, verifies its hash, and offers safe text/image/PDF preview or an exact-version download before approval. Completed checkpoint records retain this review/download entry after approval and when reopened; only pending checkpoints offer decision controls. A failed saved-definition lookup blocks launch until a version loads or the user explicitly selects a new script or edits the editor. agent({..., artifacts:[version]}) admits only approved versions and includes version/hash references in the child input. The child reads bytes through read_workflow_artifact; scripts can use readArtifact({artifactVersion, offset}). Both return base64 chunks with next_offset (null at EOF). Neither reopens the source path. Limits: 2 MiB/file, 16 files/workflow, 64 MiB retained bytes/owner, and 16 KiB per read. Deleting a retained workflow also deletes its snapshots. See examples/file-review.workflow.js. JSON/text output checkpoints remain supported; links inside them require explicit file capture. No Agent success or reviewer verdict implicitly approves a version.

Each completed child also retains host assembly evidence, bound to its run ID. The host records it before graph execution from resolved instructions, actual model/parameters, authorized tools, Skills and middleware/policies. Only safe numeric parameters and opaque keyed component versions are exposed, never raw prompts, provider kwargs or credentials. get_step exposes this historical proof; missing proof fails the workflow step. This is separate from the declarative preflight guard above. Versions compare within one host lifetime; stored proof survives restart. It describes assembly-time configuration, not later external service state, runtime tool results or deterministic replay.

The UI exposes retained outputs one at a time to keep responses bounded. Checkpoint receipts retain who decided, when, source attempt and output version. On restart these records remain inspectable. Compatible runs become recoverable; a fresh authenticated browser session must explicitly recover them. No credentials or capability handles are serialized. Start new work only after considering prior effects.

Limits and status

Limits are deployment-controlled, not writable by generated script or browser input. Defaults are in the configuration above; ceilings are concurrency 4, global concurrency 8, calls 32, active workflows 8 (4 per owner), wall time 600 seconds, admission 20 seconds, cumulative worker CPU 10 seconds, JS memory 32 MiB.

Each JS engine entry has a 50 ms CPU interruption limit; stack is 256 KiB. The isolated worker additionally has a cumulative POSIX CPU limit, no core dumps, zero file-write size allowance, a temporary working directory and a minimal credential-free environment. The parent kills/reaps it on termination. This is a capability-restricted JS interpreter in a separate process, not a general OS sandbox or a guarantee against native engine vulnerabilities.

Wall time (timeout_seconds) is the only clock bound on a run. A separate cap of 10,000 worker turns stops scripts that spin the JS job queue; idle waits on pending Agent calls do not exchange frames with the worker and do not consume turns, so long child runs are limited only by the wall deadline. The local wait checks worker exits every 20 ms alongside cancellation and faults; an exit triggers prompt failure handling and cleanup of pending child runs.

IPC frames are bounded to 48 KiB. Script JSON encoding is at most 16,000 bytes, arguments 4,000 bytes, task 8,000 bytes, each captured Agent output/final result 12,000 bytes. There are at most 20 progress messages of 160 JSON bytes each and 100 retained workflows per owner. Inspect responses are bounded to 60 KiB. Unicode limits apply to the JSON encoding too, including escapes. Oversized results fail explicitly instead of truncating evidence silently. Latest list returns 20 records; keep a workflow run ID to inspect older retained records.

There is no hard dollar-cost limit. Call/time/CPU limits and ordinary host token policies do not constitute a shared workflow currency budget. Unknown configuration keys such as max_cost_usd are rejected. Add a generic, authoritative host budget reservation/enforcement contract before advertising that guarantee.

State	Meaning
queued / running	Supervised execution in this Gateway process
completed	Script and awaited child calls returned; output is unapproved task data
failed	Script, resource limit (including wall deadline), attribution, child execution or observation failed
cancelled	Stop requested and known active children interrupted or already terminal
paused / waiting_approval	Live worker retained at an explicit script checkpoint; occupies an active workflow slot
waiting_input	Child has a graph interrupt or human-input artifact; downstream stopped
needs_reconciliation	Admission/cancellation outcome uncertain; inspect child identities before new work
recoverable	Restart/shutdown retained a compatible execution; sign in and select Recover workflow
interrupted	Legacy record, cancelled startup record, or externally interrupted supervisor; inspect child effects

Wall-clock expiry reports failed with Execution deadline exceeded and cleans up tracked children and the worker. A timeout after child admission reports child observation failure and interrupts/observes the known run; only uncertain cleanup escalates it to needs_reconciliation. Admission timeouts without a known run ID retain the stable child thread identity for reconciliation.

Allowlist order does not change request identity; adding or removing allowed Agent references does. Matching retries still return the retained record after restart.

Cancel is asynchronous and never rolls back side effects. The service retains in-flight admission until its bounded response returns, records the actual child run ID, then explicitly interrupts and observes that child. If admission times out or authorization is revoked during cleanup, it retains needs_reconciliation with stable thread/input/idempotency identity. It never automatically retries an uncertain admission. Stable request IDs return an existing workflow record; they never themselves resume it or reexecute completed work; use the explicit checkpoint action. Changed scripts/args/limits with the same request ID conflict. Definition versions are pinned; editing a definition creates a new version.

Caller cancellation during launch does not abandon a committed record: the service owns persistence through supervisor publication, including shutdown coordination. A matching retry returns that same supervised record rather than an unowned queued launch. This does not add execution replay or resume. Cancellation of a recoverable workflow is also service-owned: disconnecting the caller does not abandon child cleanup or its final status write. Shutdown drains that cleanup before releasing the store's process lock. If a background action fails after disconnection, the Gateway logs its exception type at error level so operators can inspect retained workflow and child records.

Result collection anchors on the visible human input, including the host's canonical __user rewrite after dynamic context injection. Hidden system/memory reminders cannot become the anchor; genuinely later human input still conflicts. Result collection checks input message/run attribution and rejects an intervening human turn, because get_state() is the thread's latest state, not immutable run output. Results are copied before further script calls. Per-step inputs remain private. Owner-scoped get_step returns one immutable retained output with its attempt and artifact version; run inspection returns bounded metadata. Child conversations remain accessible through normal host authorization.

At startup, compatible unfinished records become recoverable; legacy or cancelling records become interrupted. Retained IDs do not recreate a capability by themselves. Gateway revokes handles during shutdown, so cleanup may require reconciliation. Paused/approval records become recoverable; committed decisions retain their exact version and can continue through the recovery contract below. Neither graph resume nor tool permission approval is interpreted as authenticated approval of an artifact version.

Verify

Backend CI installs QuickJS as a POSIX development dependency; the extension declares its own pinned runtime dependency. No provider keys are required for these checks.

cd backend
uv run pytest tests/test_workflow_plugin.py -q
make test
make test-blocking-io
make format

Browser checks use a synthetic loopback fixture, not a deployed Gateway:

node examples/deerflow-extension-workflows/verify_browser.mjs
# If using an installed Chrome instead of downloaded Playwright Chromium:
PLAYWRIGHT_CHANNEL=chrome node examples/deerflow-extension-workflows/verify_browser.mjs

Install frontend dependencies first, or set PLAYWRIGHT_MODULE to an absolute Playwright ES module path. The suite exercises launch, inspect, child navigation, cancel, escaped output, deletion and disposal. Backend tests include the real Gateway/LangGraph bridge with deterministic test nodes, plus controlled admission races, limits, owner scope, service shutdown and restart records.

The implementation uses an original small JSON bridge. deer-workflow was evaluated for API shapes but is not imported or copied: its dynamic Node module loader, unbounded fan-out and external CLI Agent adapters are not used here.

Phase 3 recovery contract

Recovery is explicit and owner-scoped. In Script workflows, select a recoverable run and Recover workflow. This is a browser action, not a model tool. It obtains a fresh session-bound AgentRuns capability and checks current permissions, declarative configuration, operator limits, script/arguments, and runtime compatibility before starting a replacement worker. Recovery itself does not approve pending human output; review the same retained version and approve or reject it separately. Duplicate recovery requests share one active worker.

The extension persists a versioned bridge journal: each emitted request frame is committed before host operations; each response batch is committed before it is returned to JavaScript. Recovery evaluates the unchanged script from its start, verifies its request frames against that journal, and feeds back recorded responses in their original order. Confirmed Agent results are reused rather than dispatched again. It reconstructs script variables without serializing a JS heap. Date and Math.random are unavailable; pass timestamps/random values in args. A divergent history stops before issuing new effects. The journal is bounded at 4 MiB and the complete record at 8 MiB per run; the worker has a 10,000-round limit.

Crash boundaries have explicit outcomes:

Boundary	Recovery behavior
Before child admission intent	A queued step may be admitted with its original identity/input/key
After admission intent, before run ID is stored	needs_reconciliation; never resubmit an uncertain Agent call
Known child run, before result is stored	Observe that run without starting it again; validate success, message attribution and host evidence before retaining the result
Child interrupted/failed or external outcome uncertain	Stop; inspect child identities and reconcile effects before starting new work
Approval persisted, before downstream dispatch	Reuse that exact decision and continue through the recorded boundary
File captured, before workflow metadata is stored	Recover the immutable stored bytes by capture step; never overwrite with a newer source

There is no automatic retry or operator override of uncertain external effects. Cancellation requests interruption of known children and cannot undo committed business effects. Recovery does not resume a child's interrupted graph. Legacy Phase 1/2 records have no replay journal and remain inspection-only after restart. Normal shutdown preserves compatible pending waits; interrupted active children may require reconciliation.

Execution time remaining is retained. A crash during active execution consumes elapsed wall time including downtime; a persisted human/pause wait suspends the execution budget, but its original absolute wait expiry still applies. Replay also consumes the remaining execution budget. The CPU limit is per worker; Agent-call and log quotas are retained across recovery.

The workflow runtime source and QuickJS version must match. Incompatible code, script/arguments, configuration or operator-limit changes reject recovery rather than silently migrating execution. The durable configuration digest uses a purpose-separated HMAC derived from the host's persisted signing secret. Preserve that secret and the Gateway's durable run/thread/checkpoint data across restart; secret rotation invalidates recovery. Stored assembly evidence remains historical and is distinct from this configuration preflight check.

Phase 3 and Phase 4 share the design: stable step/attempt and idempotency identities, conditional record revisions, a durable intent/result journal, and fresh authority are the foundations for later leases and fenced dispatch. Phase 3 still requires one Gateway process per workflow store. It does not implement replica routing, leases, automatic takeover or cluster-wide quotas; these belong to Phase 4. Keep the exclusive process lock until those guarantees exist.