[ForeignKeyCN]

Summary

Brings the To Do plugin in line with Outlook (#4163), Teams (#4164), OneDrive (#4165) and Excel (#4166), and with n8n's Microsoft To Do node. The plugin was built on two third-party packages (pymstodo, dify-easy) and on requests-oauthlib; this PR replaces them with direct Microsoft Graph calls through a shared tools/graph_client.py.

Fixed: credential validation always failed and put secrets in its message. _validate_credentials ended with a debugging leftover that raised unconditionally with f"token: {token} ... credentials: {credentials}", i.e. the access and refresh tokens and the client secret, shown wherever the validation error is displayed. Validation now reads the task lists and reports a plain message; a test checks that no secret appears in it.

1. Base (existing workflows keep working)

• The 8 tools keep their names, parameters and output ({"data": [...]} / the object in json, str() of it in text), including the historical quirks: get_tasks returns the task lists, and the task tools return only tasks that are not completed by default. Dates keep their previous text form.
• OAuth authorizations made before 1.0.0 stored the whole token as JSON text under token; tools read it, the refresh accepts it and writes the new fields (access_token, refresh_token, graph_base_url). The refresh no longer sends scope. The OAuth scopes are unchanged (openid offline_access Tasks.ReadWrite, the ones pymstodo requested).
• No more class-level state: the old OAuth code set ToDoConnection._redirect globally on every request.
• IDs are path-segment encoded, paging only follows Graph's own links, and a stored Graph host other than a Microsoft Graph endpoint is refused.
• OAuth tenant and national clouds: optional Tenant ID (default common, as before) and Microsoft Cloud; scopes are qualified outside the global cloud (openid / offline_access excepted).
• Typed output variables on every tool.
• YAML used zh_CN, which Dify does not show; now zh_Hans.

2. Auth modes (API Key credential)

• Service Principal (n8n has it): application permission Tasks.ReadWrite.All; tools work on /users/{owner}/todo, the owner coming from the tool's Task Owner setting (form-only, never chosen by the LLM) or the credential's default. Saving with a default owner reads their lists to check the permission.
• Each user signs in, same design as the other Microsoft plugins: authorization code + PKCE through a plugin endpoint (GET /todo/callback) that never holds the secret; per-user tokens Fernet-encrypted in plugin storage, keyed by a hash of client_id | Dify user ID; never in tool output or logs. Scopes: OAuth's plus User.Read (to name the signed-in account). Sign Out of To Do (todo_sign_out).

3. n8n parity (new tools carry a todo_ prefix: the new Agent rejects duplicate tool names across plugins)

n8n	Tool
List: Get Many / Get	get_lists / get_list_by_id (existing)
List: Create / Update / Delete	todo_create_list / todo_update_list / todo_delete_list
Task: Get Many / Get	get_tasks_by_list_id (new status_filter, limit) / get_task_by_id (existing)
Task: Create	create_task, now with n8n's reminder_datetime, importance, status besides due_date and body_text
Task: Update / Delete	todo_update_task / todo_delete_task
Linked Resource: Create / Get / Get Many / Update / Delete	todo_create_linked_resource / todo_get_linked_resource / todo_list_linked_resources / todo_update_linked_resource / todo_delete_linked_resource

get_all_tasks and complete_task stay; get_all_tasks takes the same options and adds each task's list_id / list_name.

Version 0.0.8 → 1.0.0. README rewritten (the existing setup screenshots are kept; it now also lists the API permissions to add, which it did not before) and PRIVACY updated. Dependencies: pymstodo, dify-easy, requests-oauthlib, structlog, pydantic removed; cryptography added.

Release Notes

• Fixed: saving an authorization always failed with an error that included the access token and client secret.
• Each user signs in: a new authorization for chat agents; each person signs in once with their own Microsoft account and the tools work on their own tasks. Needs the new sign-in endpoint registered as a Web redirect URI on the app.
• Service Principal authorization (app-only), working on a named user's tasks.
• OAuth: optional Tenant ID and Microsoft Cloud (US Government, DoD, China/21Vianet). Existing authorizations keep working.
• New tools matching n8n: create, rename and delete lists; update and delete tasks; create, read, list, update and delete linked resources. Create Task gains reminder, importance and status; the task lists can include completed tasks.
• Every tool returns typed output variables; Chinese labels now show.

Change Type

• Documentation / non-plugin change
• Non-LLM plugin (tools, extensions, datasource, etc.)
• LLM plugin

Screenshots / Videos

The setup screenshots in the README are the existing ones. The per-user flow is the same as in #4163–#4166 (screenshots there).

Testing

• Unit tests: 77 passed (pytest; the plugin had none). They cover: the Graph context for OAuth (new and pre-1.0.0 token JSON credentials), Service Principal and per-user, national clouds and the Graph-host check; ID encoding; every tool's output variables on success and on a Graph error (a test checks every tool in the provider is covered); the pre-1.0.0 output shapes (task fields, date texts, get_tasks returning lists); the default "not completed" filter and the other filters; paging staying on the Graph host; the n8n task fields and their validation; linked resources (fields, URL check); OAuth URLs per tenant and cloud with the old scopes; refreshing a pre-1.0.0 credential; validation messages without secrets (and a working token now passing); the per-user sign-in flow and validation.
• On a self-hosted Dify (Community 1.16.1): the plugin installs and upgrades, the sign-in endpoint answers, and an Each user signs in credential validates against Microsoft Entra ID (client ID and secret checked).
• Not run end to end: the tools against a live To Do account (sign-in through a chat, reading and changing lists, tasks and linked resources), Service Principal against a real user, and an upgrade of a real pre-1.0.0 authorization. These are covered by the unit tests above.

Checklist

• I have read the contribution guidelines
• Version bumped in manifest.yaml (0.0.8 → 1.0.0)