> ## Documentation Index > Fetch the complete documentation index at: https://developers.respondent.io/llms.txt > Use this file to discover all available pages before exploring further. # Completion URL > Track task completion for unmoderated studies and surveys without triggering payment For unmoderated studies and surveys, researchers usually point participants to an external survey, prototype, or task. The **`completionUrl`** is how you get an authoritative signal that a participant finished that task — **without** moving them to `ATTENDED` and triggering payout. This separation matters for API partners. Because the API requires autopay to be enabled, [Mark as attended](/screener-responses/mark-as-attended) immediately starts the incentive payment. Most partners want to inspect the quality of a response (manually or via automated checks) before paying. `completionUrl` gives you a clean "task is done, participant is ready for review" signal in between those two states, and it's visible to both you and the researcher on the screener response. This page covers: * What `completionUrl` is and what the `cc` parameter means * All the ways a task can get marked complete (and what each one is for) * How task completion relates to marking a participant as **attended** ## What is `completionUrl`? When you create a project where `targetResearchMethodology` is `unmoderatedStudy` or `survey`, the [project response](/projects/retrieve-a-specific-project) includes a `completionUrl` field. It looks like this: ``` https://app.respondent.io/complete?cc= ``` * `completionUrl` is generated by Respondent. You cannot set it on create or update — it comes back on the project response. * The `cc` query parameter is the **project completion ID**: a unique identifier that lets Respondent associate the incoming participant with the right screener response on the right project. It is not a participant identifier on its own — Respondent also requires the participant to be signed in to their Respondent account in the same browser session. You should: 1. Place the URL of the external survey, study, or task in `unmoderatedStudyOrSurvey.remoteCommunicationDetails` when [creating the project](/projects/create-a-project) (see [Project deep dive](/docs/Projects/project-deep-dive#unmoderated)). 2. Configure the survey or task tool to redirect to `completionUrl` once the participant finishes. When the participant lands on `completionUrl`, Respondent: * Sets `task.status` to `complete` on their screener response * Sets `task.completedAt` to the current timestamp (this appears on the screener response object — see [Mark as attended](/screener-responses/mark-as-attended) response schema) * Stops any pending task-completion reminder emails for that participant ## How tasks get marked complete There are three ways `task.status` becomes `complete` on a screener response. Only the first one is something you, as an API partner, plug into directly. | Path | Who triggers it | When to use | | ------------------------------------------------- | ----------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Participant hits `completionUrl` | The participant, redirected from your task tool | The standard path for API partners. The participant finishes the external survey or study and your tool redirects them to `completionUrl`. | | First-party integrations (SurveyMonkey, Lookback) | Respondent, server-side | Only relevant when a researcher connects a SurveyMonkey or Lookback task on the Researcher Platform. Respondent receives a webhook from the third party and marks the task complete with the response payload. Not available over the public API. | | Inferred from "Mark as attended" | You, via the API | If you skip task completion entirely and just call [Mark as attended](/screener-responses/mark-as-attended), the participant moves to `ATTENDED` and payout starts. This does not flip `task.status` to `complete` — the two flags are independent — but for projects driven entirely from the API it's a valid shape if you don't need the intermediate "task done, review pending" state. | There is no public API endpoint to mark a task complete directly. If you want Respondent's UI and the screener response object to reflect "task done" before you decide on payment, the only lever is to send the participant through `completionUrl` at the end of your external task. ## Task complete vs. attended `task.status` and `screenerResponse.status` are independent. Hitting `completionUrl` only touches `task.status`; calling Mark as attended only touches `screenerResponse.status`. Neither one implies the other. For API partners, that gives you a three-stage lifecycle for unmoderated work: 1. **Invited** — you've sent the participant to the task. 2. **Task complete** — they finished the task and were redirected through `completionUrl`. `task.status = complete`, `task.completedAt` is set, reminder emails stop. The participant has not been paid. 3. **Attended** — you've reviewed the response and called [Mark as attended](/screener-responses/mark-as-attended). Status moves to `ATTENDED` and autopay fires. A typical lifecycle: 1. Researcher creates the project — `completionUrl` is returned on the response. 2. Participant qualifies, you invite them, they complete the external task. 3. The external tool redirects the participant to `completionUrl`. Respondent marks the task complete and stops reminders. 4. Your system (or a reviewer) inspects the response. 5. Once you're happy, your system calls [Mark as attended](/screener-responses/mark-as-attended) — `ATTENDED` + autopay. 6. If the response is unacceptable, call [Mark as rejected](/screener-responses/mark-as-rejected) or [Mark as no show](/screener-responses/mark-as-no-show) instead. Don't treat `completionUrl` as a payment trigger. It's a "ready for review" signal. Payment only starts when you call Mark as attended. ## How `cc` interacts with the other URL parameters The `cc` parameter on `completionUrl` is separate from the [URL parameters](/docs/Screener-responses/URL-Parameters-for-Project-Link) that Respondent appends to your `remoteCommunicationDetails` link (`respondent_profile_id`, `respondent_screener_response_id`, and so on). * The **outbound** link from Respondent to your task tool carries the `respondent_*` parameters so your tool knows which participant and screener response it is dealing with. * The **return** link back to Respondent (`completionUrl`) carries `cc` so Respondent can identify which project's task is being marked complete. The participant identity comes from the signed-in Respondent session, not from `cc`. You can pass `cc` through your survey tool as a hidden field and use it as part of the final redirect, or you can hard-code the project's `completionUrl` as the redirect target — both work. ## When `completionUrl` is and isn't returned | Methodology | `completionUrl` returned? | | ------------------------------------------------------------------ | ------------------------- | | `unmoderatedStudy` | Yes | | `survey` | Yes | | `diaryStudy` | No | | `oneOnOne`, `focusGroup`, `inRespondentHome`, `inRespondentOffice` | No | For moderated methodologies, task completion is determined by the meeting actually happening — there is no equivalent self-reported completion link.