If you're evaluating a task management API for client work, the real question is not whether it can create a task. Most can. The question is whether it can automate the operational work around tasks: onboarding, approvals, reminders, handoffs, reporting, and recurring delivery.
Most project management tools let you use them. Sydnee also lets you build on top of them.
The Sydnee public Task API gives you full programmatic control over client task boards — create tasks, update statuses, set priorities, move cards across sections, post comments, manage recurring rules, assign to team or portal users, and more. It's a REST task API with OAuth-secured API keys, cursor-based pagination, and detailed error envelopes built for automation scripts, integrations, and AI agents alike. If you want the broader product overview, Sydnee API Access walks through the full platform surface beyond tasks.
None of that is "crazy" in the sense that the UI can already do many of the same actions. The reason to reach for the API is not that clicking buttons is impossible. It's that the API lets Sydnee react to outside events, run the same workflow across dozens of clients, keep boards in sync after hours, and create tasks with data the UI would otherwise require someone to enter manually.
Use the UI when a person is making a one-off decision. Use the API when the work should happen automatically, repeatedly, or at scale.
The examples below focus on real operational use cases for a client-facing task API, not generic CRUD demos. Each one answers a practical question teams run into when they start comparing a task API against just managing work manually in the UI. If you're still evaluating whether Sydnee's API is the right fit at all, start with the API access overview and then come back here for the task-specific workflows.
Here are 10 concrete use cases, each with the exact API calls that power them.
1. Auto-Populate an Onboarding Board When a New Client Signs
Sydnee has task templates built in — you can build a standard onboarding checklist once, then apply it to any new account with two clicks (merge into existing sections or add as new ones). For most agencies, that's exactly what you need.
The API goes further. When a client signs a contract in your CRM or proposal tool, a script can apply your template logic automatically — no one has to remember to open Sydnee and do it manually. And critically, the API lets you assign portal users (your clients) to tasks at creation time, which the template UI doesn't currently support.
How it works:
- Your proposal tool or CRM fires a webhook when a contract is signed.
- Your script calls
GET /v1/accountsto confirm the account exists (Sydnee creates accounts automatically, or you look up by name). - It calls
GET /v1/accounts/{accountId}/task-boardsto get the default board ID. - Then loops through your onboarding template definition and fires one
POST /v1/accounts/{accountId}/task-boards/{boardId}/tasksper item — with assignees, due dates, and client visibility already set.
POST /v1/accounts/acct_123/task-boards/board_cuid_17/tasks
Authorization: Bearer YOUR_API_KEY
Content-Type: application/json
{
"title": "Send brand questionnaire",
"sectionId": "section_cuid_91",
"assigneeUserIds": [88],
"due": {
"kind": "SINGLE",
"startAt": "2026-06-05T17:00:00.000Z",
"endAt": null,
"startHasTime": true,
"endHasTime": false,
"repeating": null
},
"clientAccess": {
"visibleToClients": false,
"editableByClients": false
}
}A 30-client agency onboarding batch that used to take an hour of clicking now runs in seconds.
2. Create Client-Assigned Tasks That Templates Can't
Not all tasks are internal. When you need a client to take action — approve a logo, review copy, provide brand assets — you can create a task that shows up on their portal dashboard, with them set as the assignee.
If you're doing this once for one client, the UI is fine. The API becomes the better tool when that assignment should happen automatically from an intake form, proposal approval, or another system before anyone on your team opens the account.
This is where the API has a specific edge over task templates today: templates in the Sydnee UI don't currently support assigning portal users at the time a template is applied. If you want a client pre-assigned to a task when it's created, the API is the way to do it.
Set clientAccess.visibleToClients: true when creating the task and the client sees it the moment they log in. Set editableByClients: true and they can mark it done themselves. Pass their portal user ID from GET /v1/accounts/{accountId}/users in assigneeUserIds and it's assigned to them on creation.
{
"title": "Approve homepage hero copy",
"clientAccess": {
"visibleToClients": true,
"editableByClients": true
},
"due": {
"kind": "SINGLE",
"startAt": "2026-06-15T00:00:00.000Z",
"endAt": null,
"startHasTime": false,
"endHasTime": false,
"repeating": null
}
}This replaces the email thread that says "just circling back to see if you'd had a chance to look at the copy..." The client has a task. It has a due date. It either gets approved or it shows as overdue.
3. Roll Out a Campaign Kickoff Checklist to Every Client at Once
You're launching a new service package — brand refresh, say — and every client on that tier needs the same kickoff checklist: discovery call booked, brand audit requested, competitive review assigned to a strategist.
One loop. One script. Every client gets the same starting line. This is exactly the kind of rollout you would not want to click through manually in the UI if 40 existing clients need the same setup this afternoon.
const clients = await listAllAccounts(); // GET https://public-api.sydnee.app/#tag/accounts/GET/v1/accounts
for (const client of clients) {
const boards = await getTaskBoards(client.id);
const board = boards.defaultBoardId;
await createTask(client.id, board, {
title: "Submit existing brand assets",
sectionId: "section_kickoff",
due: {
kind: "SINGLE",
startAt: "2026-07-01T17:00:00.000Z",
endAt: null,
startHasTime: true,
endHasTime: false,
repeating: null,
},
clientAccess: { visibleToClients: true, editableByClients: false },
});
}You just turned a multi-day setup project into a 45-second script. Every client wakes up to the same kickoff task in their portal, and your team opens a consistent board for each one.
4. Escalate Overdue Tasks Automatically
A client deliverable slips past its due date. Another day goes by. The task is still sitting at NORMAL priority, invisible in a stack of other work. Instead of a producer manually triaging every morning, build a script that escalates priority automatically.
GET /v1/accounts/{accountId}/task-boards/{boardId}/tasksThe response includes due.isOverdue on every task. Loop through, find everything that's overdue and still at LOW or NORMAL priority, and bump it:
PATCH /v1/accounts/acct_123/task-boards/board_cuid_17/tasks/task_cuid_4401/priority
{ "priority": "URGENT" }Run this as a nightly cron. Your team opens Sydnee in the morning and the red URGENT badges are already there — no standup required to surface what's on fire.
5. Move Tasks Through Your Production Pipeline Automatically
If you set your task board up with sections like Brief, In Production, Client Review, and Approved, the API can move work between them automatically. When a designer marks a Figma file as ready in your design tool, or a video editor exports the final cut, that event should move the task forward automatically — not wait for someone to drag it.
POST /v1/accounts/acct_123/task-boards/board_cuid_17/tasks/task_cuid_4401/move
{
"sectionId": "section_client_review",
"index": 0
}The response confirms the new section name and position. The account manager opens their board and the card has already advanced to Client Review — no Slack message needed to hand off the work. Combine this with webhooks from Figma, Frame.io, or your internal render pipeline and you have a real production workflow, not just a to-do list.
6. Set Up Recurring Deliverable Cycles with Repeating Tasks
You manage social content for 15 clients. Every month: content calendar review, copy approval, creative sign-off, scheduling confirmation. Rather than recreating those tasks manually — or watching someone forget the second one — use the repeating field when creating them.
For a single board, the UI may be enough. The API matters when those dates, assignees, or reminder rules need to be generated from another calendar, applied across many accounts, or rebuilt from a system outside Sydnee.
{
"title": "Review monthly content calendar",
"due": {
"kind": "SINGLE",
"startAt": "2026-06-01T00:00:00.000Z",
"endAt": null,
"startHasTime": false,
"endHasTime": false,
"repeating": {
"freq": "MONTHLY",
"byMonthDay": [1]
}
}
}When someone marks a recurring task complete, the API response includes newRepeatingTask — the ID of the freshly created next occurrence. You can use that to immediately set the next cycle's assignee, wire up a reminder, or log it in your reporting pipeline.
7. Append Context from External Tools to Task Descriptions
Your project intake form captures scope notes. Your time-tracking tool logs a scope change. Your client sends a Loom with revision feedback and your team logs a summary.
Instead of opening Sydnee and typing it all in manually, pipe those notes directly into the task description using append mode:
PATCH /v1/accounts/acct_123/task-boards/board_cuid_17/tasks/task_cuid_4401/description
{
"mode": "append",
"format": "plain-text",
"content": "Client Loom review 5/29 — wants headline shortened and CTA moved above the fold."
}The API returns both html and plainText representations of the updated description so you can store it in your system of record too. No copy-paste. No "I thought someone updated that."
The win here is not that typing in the UI is hard. The win is that the source information already exists somewhere else, and the API keeps Sydnee synced to that source automatically.
8. Post Structured Updates as Task Comments
Need a full revision trail, not just a description append? Comments are the right tool. They're timestamped, attributed, and surface in the task activity feed — useful when a client later asks "why did we change this?"
Again, this is not about avoiding one manual comment. It's useful when another system, workflow, or agent should leave a structured audit trail the moment work changes.
POST /v1/accounts/acct_123/task-boards/board_cuid_17/tasks/task_cuid_4401/comments
{
"content": {
"format": "plain-text",
"content": "Round 2 complete — incorporated all client feedback. Pending final sign-off."
}
}You can also GET the comment thread to pull a task's full revision history into your reporting pipeline, client-facing dashboard, or AI summarization layer.
9. Reassign Work When an Account Switches Hands
A senior designer goes on leave. A client account moves to a new strategist. You don't want a board full of tasks silently attributed to someone who's no longer on the project — especially when the client can see some of them.
If one task needs to move, the UI is faster. If a handoff affects dozens of open tasks across one or more accounts, the API is the safer way to sweep everything at once.
PATCH /v1/accounts/{accountId}/task-boards/{boardId}/tasks/{taskId}/assignees
{ "assigneeUserIds": [91] }Run this across all open tasks for the departing team member. Every task flips to the new assignee in one sweep. No orphaned work, no missed handoff.
10. Point an AI Agent at the API and Let It Work
The Task API endpoints were designed with AI access in mind — the error envelopes include an agentHint field, API keys scope to a single organization, and the cursor-based pagination is deterministic and resumable so agents can pick up where they left off. The rate limits (300 reads / 100 writes per minute) are generous enough that an AI can scan an entire client's board and take meaningful action in a single pass.
What that actually looks like in practice:
Board cleanup. Point an AI at a board with a hundred stale tasks. It lists them, reads the descriptions and due dates, archives anything that's been completed and untouched for 60+ days, bumps anything overdue to URGENT, and posts a comment on anything ambiguous explaining what it did and why.
Inbox-to-task. A client emails with revision notes. The agent creates a task, assigns the right team member, appends the email content as the description, and posts a comment with a link back to the original thread.
Weekly digest. Every Friday, an agent scans all open tasks across your active accounts, reads the comment threads, and posts a summary comment on anything that hasn't moved in a week — surfacing the stuck work without anyone having to triage manually.
Scope change logging. A call ends, someone pastes the notes into a chat window. The agent finds the relevant tasks, appends the scope change to each description, and flags any task that's now likely to slip its due date by bumping priority.
None of this requires anything beyond an API key and a language model that can make HTTP calls. The full REST surface is already there.
The Full API Surface
Here's the complete list of task endpoints in the Sydnee public API:
Read and create
GET /v1/accounts/{id}/task-boards— List all task boards for a client.GET /v1/accounts/{id}/task-boards/{boardId}/sections— List sections (Kanban columns).GET /v1/accounts/{id}/task-boards/{boardId}/tasks— List tasks, optionally filtered by section.POST /v1/accounts/{id}/task-boards/{boardId}/tasks— Create a top-level task.GET /v1/accounts/{id}/task-boards/{boardId}/tasks/{taskId}— Fetch full task detail.POST /v1/.../tasks/{taskId}/subtasks— Create a subtask under a parent.
Update and move
PATCH /v1/.../tasks/{taskId}/status— Mark complete or reopen.PATCH /v1/.../tasks/{taskId}/priority— SetLOW,NORMAL,HIGH, orURGENT.PATCH /v1/.../tasks/{taskId}/due— Set or clear a due window (SINGLEorRANGE).PATCH /v1/.../tasks/{taskId}/description— Replace or append the description.PATCH /v1/.../tasks/{taskId}/assignees— Replace the full assignee set.POST /v1/.../tasks/{taskId}/move— Move a task to a section and position.PATCH /v1/.../tasks/{taskId}/archive— Archive or restore a task.
Reminders and comments
POST /v1/.../tasks/{taskId}/reminders— Add a reminder rule.DELETE /v1/.../tasks/{taskId}/reminders/{id}— Remove a reminder rule.GET /v1/.../tasks/{taskId}/comments— Fetch the comment thread.POST /v1/.../tasks/{taskId}/comments— Post a comment.
Getting Started
API keys live in your Sydnee settings under Integrations → API. The full OpenAPI spec is available at https://public-api.sydnee.app/openapi.json — drop it into your HTTP client, import it into Cursor, or feed it to your AI agent.
If you want the human-readable reference instead of the raw spec, the main task docs live at public-api.sydnee.app, with direct docs for task boards, create task, update due, and comments.
For the higher-level product and pricing context around API access, see sydnee.app/api-access.
Rate limits are per-key with Retry-After headers on 429 responses, so scripts can back off gracefully without manual intervention.
The best production systems are the ones that feel invisible. The Task API is built so you can build exactly that.
