HiAPI TASK_FAILED Error: Causes and How to Fix It

When you submit an async job to the HiAPI task API, a successful submission returns HTTP 200 with a taskId. The job then runs in the background, and when you poll it, it can end in a terminal fail state. The poll response looks like this — note the HTTP call itself is still 200:

{
  "code": 200,
  "data": {
    "taskId": "tk-hiapi-01M4RK...",
    "model": "seedream-5.0-lite/image-to-image",
    "status": "fail",
    "error": { "code": "TASK_FAILED", "message": "task failed" },
    "created": 1791827316,
    "completed": 1791827352,
    "storage": "temp"
  },
  "message": "success"
}

This is what people mean by a "TASK_FAILED error": the request was accepted, the task ran, and it finished unsuccessfully. It is not an HTTP 4xx error and not a timeout. This guide shows how to read that payload and fix each cause.

First: TASK_FAILED is not an HTTP status

The single most important thing to understand:

• The HTTP status of the poll call is 200. The envelope even says "message": "success" — that only means the API call succeeded, not that your job did.
• "status": "fail" (inside data) is how you know the job failed. For a finished job, data.status is either "success" or "fail".
• "TASK_FAILED" is the value of data.error.code, not the status. Some failures carry a more specific code and a more useful message (see below).

So always poll GET /v1/tasks/{taskId} and branch on data.status. Never decide success from the HTTP code alone.

Common causes of a terminal fail

Ordered roughly by how often they show up.

1. A broken or non-public input image/video URL

This is the most common cause for image-to-image and image/video-to-video jobs. If your input references a URL the platform cannot fetch, the task is accepted but fails while running. A real terminal payload:

"error": {
  "code": "INVALID_REQUEST",
  "message": "The image URL could not be downloaded. Please provide a reachable public HTTP(S) URL and try again."
}

Here the message is explicit. Other models surface the same root cause as the generic TASK_FAILED / "task failed".

Fix: host the input on a public HTTPS URL and verify it before submitting:

curl -I "https://your-host.example.com/input.png"
# must return 200 and a direct image/video content-type
# not 401/403/404, and not an HTML page

Expired pre-signed URLs, localhost/private addresses, and links that require a login are the usual culprits.

2. A transient or upstream generation failure

Sometimes a well-formed job fails with the generic error.code: "TASK_FAILED", message: "task failed" and no further detail. These are usually transient.

Fix: retry the job once or twice. If it keeps failing with identical input, simplify the input (shorter prompt, drop optional fields) and re-run to isolate the trigger.

3. An option the model rejects

Most invalid parameters are caught at submission time as an HTTP 400 (you never get a taskId) — see the next section. Occasionally a specific combination of otherwise-valid options is only rejected once the job runs, landing in data.status: "fail". The error.message names the offending option.

Fix: read data.error.message, then check the model's supported inputs on its model page (for example, the GPT Image 2 model page) and remove or correct the field it names.

How to tell TASK_FAILED apart from 4xx and timeouts

Three different situations all get called "it failed." They have different fixes:

If you never received a taskId, you did not hit a TASK_FAILED — you hit a request error:

• HTTP 400 invalid, missing, or unsupported parameter → Fix HiAPI 400 Bad Request
• HTTP 401 invalid API key → Invalid API Key Errors
• Insufficient balance (rejected at creation, so there is no task to fail) → Fix HiAPI 402 Insufficient Balance
• Unknown or unlisted model id (MODEL_UNAVAILABLE) → "model not found" / "model not available"
• A task that never reaches a terminal state → HiAPI Task Timeout and 504 Errors

Fix checklist

1. Poll the task, don't trust the POST. Submission only tells you the job was queued. Call GET /v1/tasks/{taskId} and look at data.status.
2. Confirm it's a real failure: data.status == "fail" (the HTTP code will be 200).
3. Read data.error.code and data.error.message. The message is your primary signal.
4. If it mentions the input URL: make the URL public and reachable; verify with curl -I (200 + a direct media content-type).
5. If the message is generic ("task failed"): treat it as transient — retry; if it persists, simplify the input.
6. Confirm the model id is currently listed via GET /v1/models and matches exactly what you sent. An unknown id fails at submit as 400 MODEL_UNAVAILABLE, not as a terminal fail.
7. Check the model's supported fields on its model page and drop anything unsupported (those usually 400 at submit).
8. No taskId at all? It wasn't a TASK_FAILED — jump to the matching request-error guide above.

Minimal verification example

Before debugging a specific job, confirm your key and connectivity with one clean request to the unified task endpoint. A bare model id works (no endpoint suffix required):

# 1) Submit — expect HTTP 200 with a taskId
curl -s https://api.hiapi.ai/v1/tasks \
  -H "Authorization: Bearer sk-YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"gpt-image-2","input":{"prompt":"a red bicycle on a white background","aspect_ratio":"1:1"}}'
# -> {"code":200,"data":{"taskId":"tk-hiapi-..."},"message":"success"}

# 2) Poll — swap in the taskId you got back
curl -s https://api.hiapi.ai/v1/tasks/tk-hiapi-xxxxxxxx \
  -H "Authorization: Bearer sk-YOUR_KEY"
# -> data.status is "handling" while it runs, then "success" or "fail"

If step 1 returns 200 and a taskId, your key and endpoint are fine and any failure is a per-job issue, not a setup issue. If step 1 returns 401, your key is wrong — manage keys in your HiAPI dashboard. (This example submits a real generation.)

FAQ

Is TASK_FAILED an HTTP status code? No. The HTTP call returns 200. TASK_FAILED is the value of data.error.code inside a terminal payload whose data.status is "fail".

data.status says "fail" but I was looking for "TASK_FAILED" — which is correct? Both are correct, in their place. data.status is always "success" or "fail" for a finished job. "TASK_FAILED" is a generic data.error.code; a failed job may instead carry a more specific code (such as INVALID_REQUEST) with an actionable message.

My task is stuck on handling and never fails or succeeds. That's a timeout, not a failure. Keep polling or raise your client timeout; see HiAPI Task Timeout and 504 Errors.

I got a 400, 401, or 402 instead of a taskId. Those are request rejections — no task was created, so nothing "failed." Fix the request, key, or balance using the guides linked above.

Was I charged for a failed task? See Are failed HiAPI requests charged? for how up-front reservations and refunds work on failures.

How do I know it's a broken input URL? Read data.error.message. A URL problem typically says the image or video could not be downloaded; verify the link with curl -I returns 200 and a direct media file.