Storage inspector experimental by Light2Dark · Pull Request #8299 · marimo-team/marimo

Light2Dark · 2026-02-13T11:15:33Z

📝 Summary

Adds storage inspector feature under a feature flag.

🔍 Description of Changes

📋 Checklist

I have read the contributor guidelines.
For large changes, or changes that affect the public API: this change was discussed or approved through an issue, on Discord, or the community discussions (Please provide a link if applicable).
Tests have been added for the changes made.
Documentation has been updated where applicable, including docstrings for API changes.
Pull request title is a good summary of the changes - it will be used in the release notes.

vercel · 2026-02-13T11:15:38Z

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marimo-docs	Ready	Preview, Comment	Feb 21, 2026 0:25am

## 📝 Summary  - Adds a feature flag to enable storage inspector - Implements frontend features for storage inspector including: - Downloading a file - Searching a file (must have been expanded, only client-side search). This is consistent with cloudflare / aws where they do client-side searching rather than server-side search which can be expensive. - UI display for file types, file size, last modified - Refactors UI components across session-panel for reuse here. <img width="437" height="537" alt="image" src="https://github.com/user-attachments/assets/21f3230b-5444-4359-949c-16dbff845b6b" /> https://github.com/user-attachments/assets/96bedd6a-ee0e-44cb-967e-8d71e1a42d67 **Future improvements** - ~Add 'copy' feature, copy the full URL~. Maybe 'copy Python snippet' to read locally in Python - Preview file (open file in external browser / sidepanel / expanded) - ~Refresh connection~ ## 📋 Checklist - [x] I have read the [contributor guidelines](https://github.com/marimo-team/marimo/blob/main/CONTRIBUTING.md). - [x] For large changes, or changes that affect the public API: this change was discussed or approved through an issue, on [Discord](https://marimo.io/discord?ref=pr), or the community [discussions](https://github.com/marimo-team/marimo/discussions) (Please provide a link if applicable). - [x] Tests have been added for the changes made. - [ ] Documentation has been updated where applicable, including docstrings for API changes. - [x] Pull request title is a good summary of the changes - it will be used in the [release notes](https://github.com/marimo-team/marimo/releases).

## 📝 Summary  adds docs + link to docs from the editor. small fix to capitalize the display_name of storages. <img width="1512" height="824" alt="image" src="https://github.com/user-attachments/assets/077c8dcd-e50c-4f9a-b128-5853cef5ee45" /> video https://github.com/user-attachments/assets/d3f7d33c-4fb8-4290-a9b7-054662d33f30 ## 📋 Checklist - [x] I have read the [contributor guidelines](https://github.com/marimo-team/marimo/blob/main/CONTRIBUTING.md). - [x] For large changes, or changes that affect the public API: this change was discussed or approved through an issue, on [Discord](https://marimo.io/discord?ref=pr), or the community [discussions](https://github.com/marimo-team/marimo/discussions) (Please provide a link if applicable). - [ ] Tests have been added for the changes made. - [x] Documentation has been updated where applicable, including docstrings for API changes. - [x] Pull request title is a good summary of the changes - it will be used in the [release notes](https://github.com/marimo-team/marimo/releases).

Copilot

Pull request overview

Adds an experimental “Storage Inspector” (remote storage browser) behind a feature flag, wiring new backend storage commands/notifications through to new UI state, panel, and API endpoints.

Changes:

Add runtime/server support for listing and downloading external storage entries (commands, callbacks, notifications, HTTP endpoints, OpenAPI updates).
Add frontend storage state + request registry and a new Storage Inspector UI in the Files panel under an experimental flag.
Add docs + examples and comprehensive unit/integration tests across backend and frontend.

Reviewed changes

Copilot reviewed 49 out of 52 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tests/_session/state/test_session_external_storage.py	Adds SessionView tests for merging/filtering storage namespaces and notification behavior.
tests/_server/api/endpoints/test_storage_endpoints.py	Adds endpoint tests for storage list/download and read-mode authorization.
tests/_runtime/test_virtual_file.py	Adds tests for `VirtualFile.create_and_register` behavior with/without context and empty buffers.
tests/_runtime/test_runtime_external_storage.py	Adds runtime tests for storage list/download success and error paths (incl. thread dispatch).
tests/_data/_external_storage/test_storage_models.py	Adds tests for `download_file()` and `display_name` behavior for storage backends.
tests/_data/_external_storage/test_get_storage.py	Updates namespace conversion expectations to use backend `display_name`; removes nullable-name case.
pyproject.toml	Removes default enabling of `storage_inspector` under experimental config.
packages/openapi/src/api.ts	Adds storage endpoints + storage command/notification schemas; updates `StorageNamespace.name` to required string.
packages/openapi/api.yaml	Adds storage endpoints + schemas mirroring runtime/server changes; updates `StorageNamespace.name` to non-null.
mkdocs.yml	Renames nav group and adds Remote Storage guide to “Working with data”.
marimo/_session/state/session_view.py	Stores/merges `StorageNamespacesNotification` and filters namespaces by variable scope.
marimo/_server/models/models.py	Adds request models for storage list/download that map to kernel commands.
marimo/_server/api/router.py	Registers new `/api/storage` router.
marimo/_server/api/endpoints/storage.py	Adds `/list_entries` and `/download` endpoints dispatching control requests.
marimo/_runtime/virtual_file/virtual_file.py	Adds `VirtualFile.create_and_register` helper with fallback to data URLs.
marimo/_runtime/runtime.py	Registers new storage commands and implements `ExternalStorageCallbacks` (list/download).
marimo/_runtime/commands.py	Introduces `StorageListEntriesCommand` and `StorageDownloadCommand` in the command union.
marimo/_messaging/notification.py	Adds `StorageEntriesNotification` and `StorageDownloadReadyNotification` to notification union.
marimo/_data/_external_storage/models.py	Makes namespace name non-null; adds `DownloadResult`, `download_file()`, and `display_name` mapping.
marimo/_data/_external_storage/get_storage.py	Uses backend `display_name` when building `StorageNamespace`.
marimo/_cli/development/commands.py	Includes storage request models in generated server API schema.
frontend/src/core/websocket/useMarimoKernelConnection.tsx	Handles storage notifications and resolves deferred storage requests; filters storage by in-scope variables.
frontend/src/core/wasm/bridge.ts	Adds unimplemented stubs for storage requests in wasm bridge.
frontend/src/core/storage/types.ts	Adds storage types/utilities including storage path keys and URL construction.
frontend/src/core/storage/state.ts	Adds Jotai reducer/atoms and `useStorageEntries` hook for lazy entry loading + caching.
frontend/src/core/storage/request-registry.ts	Adds deferred request registries for list/download storage operations.
frontend/src/core/storage/tests/useStorageEntries.test.tsx	Tests `useStorageEntries` caching/fetching behavior.
frontend/src/core/storage/tests/types.test.ts	Tests storage key helpers and URL composition.
frontend/src/core/storage/tests/state.test.ts	Tests storage reducer actions: namespaces, entries caching, and filtering.
frontend/src/core/network/types.ts	Extends request client types with storage list/download requests.
frontend/src/core/network/requests-toasting.tsx	Adds toast messages for storage request failures.
frontend/src/core/network/requests-static.ts	Adds static-mode “not in edit mode” stubs for storage requests.
frontend/src/core/network/requests-network.ts	Implements network POSTs for `/api/storage/list_entries` and `/api/storage/download`.
frontend/src/core/network/requests-lazy.ts	Ensures storage requests wait for websocket connection.
frontend/src/core/islands/main.ts	Marks new storage notifications as unsupported in islands mode.
frontend/src/core/islands/bridge.ts	Adds unimplemented stubs for storage requests in islands bridge.
frontend/src/core/config/feature-flag.tsx	Adds `storage_inspector` experimental feature flag (default false).
frontend/src/components/storage/storage-inspector.tsx	Implements the Storage Inspector UI: namespaces, tree browsing, searching, copy URL, download.
frontend/src/components/storage/components.tsx	Adds protocol and file-type icon helpers for storage inspector UI.
frontend/src/components/editor/file-tree/tests/file-explorer.test.ts	Adds tests for filtering hidden files/directories in file explorer tree.
frontend/src/components/editor/chrome/panels/session-panel.tsx	Refactors to shared panel accordion components.
frontend/src/components/editor/chrome/panels/file-explorer-panel.tsx	Adds remote storage accordion section above Files panel under feature flag.
frontend/src/components/editor/chrome/panels/components.tsx	Introduces shared styled accordion components for sidebar panels.
frontend/src/components/databases/icons/google-cloud-storage.svg	Adds Google Cloud Storage icon asset for protocol rendering.
frontend/src/components/databases/engine-variable.tsx	Stops propagation on click to avoid toggling parent accordion/row interactions.
frontend/src/components/app-config/user-config-form.tsx	Adds Settings toggle for experimental Storage Inspector.
frontend/src/mocks/requests.ts	Extends request client mocks with storage request methods.
examples/storage/general.py	Adds example notebook/script demonstrating storage backends.
docs/guides/working_with_data/remote_storage.md	Adds Remote Storage guide for using the Storage Inspector.
docs/guides/working_with_data/index.md	Updates “Working with data” index to include Remote Storage.
docs/guides/editor_features/panels.md	Updates Files panel description to mention remote storage inspection.

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mscolnick · 2026-02-23T13:21:51Z

+
+    name: ClassVar[str] = "storage-download-ready"
+    request_id: RequestId
+    url: Optional[str] = None


i dont know if the file in sharememory will be cleaned up, but something to monitor. because taking out of GA, we may want to check and instead just pass the raw bytes
cc @dmadisetti

mscolnick · 2026-02-23T13:22:18Z

+            return return_data_url()
+
+        vfile = VirtualFile(filename=vfile_name, buffer=buffer)
+        ctx.virtual_file_registry.add(vfile, ctx)


we may never remove this, so could lead to a leak

mscolnick · 2026-02-23T13:38:39Z

+        _, sep, suffix = filename.rpartition(".")
+        ext = suffix if sep and suffix else "bin"
+        return DownloadResult(
+            file_bytes=file_bytes,


another approach would would relieve some memory pressure in the marimo server and handle larger files (but also wont work for all cases), is creating a a signed url to hand back to the frontend:

https://developmentseed.org/obstore/latest/api/sign/#obstore.sign

(something to consider for a followup)

Yeah.., maybe you are right to not rely on vfiles, and return bytes as a fallback.

Light2Dark changed the title ~~Sham/storage endpoints~~ external storage endpoints Feb 13, 2026

github-actions Bot added the bash-focus Area to focus on during release bug bash label Feb 13, 2026

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Light2Dark added enhancement New feature or request preview Experimental or preview-only feature labels Feb 13, 2026

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mscolnick reviewed Feb 13, 2026

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Comment thread marimo/_data/_external_storage/models.py

mscolnick reviewed Feb 13, 2026

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Comment thread marimo/_runtime/runtime.py Outdated

Comment thread marimo/_messaging/notification.py

Comment thread marimo/_server/api/router.py Outdated

vercel Bot deployed to Preview February 13, 2026 15:07 View deployment

Light2Dark changed the title ~~external storage endpoints~~ add external storage endpoints Feb 13, 2026

vercel Bot deployed to Preview February 19, 2026 18:57 View deployment

github-actions Bot added the documentation Improvements or additions to documentation label Feb 20, 2026

vercel Bot deployed to Preview February 20, 2026 18:27 View deployment

Light2Dark changed the title ~~add external storage endpoints~~ Storage inspector experimental Feb 21, 2026

Light2Dark added 11 commits February 21, 2026 20:24

add models for download and list entries

33b8554

handle storage namespaces in session_view

0cd5ed6

add virtual file download handling

b56446a

rename file-explorer test

2bb9230

add external storage router

9132180

rename to external storage for session_view

e3bd221

comment

d15656e

test file for session_view

4186eaa

comment

f59f84d

filename fix

91fb0f6

add frontend handling

979892f

Light2Dark and others added 7 commits February 21, 2026 20:24

update openapi spec

1e9fead

use async func

f667adf

add test case for empty path

822cf2e

rename to /storage endpoints

2f76257

add handling for vfile edge cases

e0bf1f6

Light2Dark force-pushed the sham/storage-endpoints branch from 6e0040c to 299edd4 Compare February 21, 2026 12:25

vercel Bot deployed to Preview February 21, 2026 12:25 View deployment

Light2Dark marked this pull request as ready for review February 21, 2026 12:45

Light2Dark requested review from akshayka, dmadisetti and manzt as code owners February 21, 2026 12:45

mscolnick requested a review from Copilot February 22, 2026 23:17

Copilot started reviewing on behalf of mscolnick February 22, 2026 23:18 View session

Copilot AI reviewed Feb 22, 2026

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Comment thread frontend/src/core/storage/types.ts

Comment thread docs/guides/working_with_data/remote_storage.md

mscolnick reviewed Feb 23, 2026

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mscolnick approved these changes Feb 23, 2026

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mscolnick reviewed Feb 23, 2026

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Light2Dark merged commit 82fa744 into main Feb 23, 2026
61 of 77 checks passed

Light2Dark deleted the sham/storage-endpoints branch February 23, 2026 18:00

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Storage inspector experimental#8299

Storage inspector experimental#8299
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