Retrieve ComfyUI API outputs from task history and /view

Purpose and scope

After execution, identify which nodes produced results and where those results reside. Node IDs, prompt IDs and filenames are different identifiers.

Source-supported context

Official routes expose history and /view, while executed is a UI-update event. Output structures depend on the actual node rather than one universal fixed field. Source 1 Source 2

Before you start

1. Keep the accepted prompt_id, target instance and authorized access method.

2. Use an output node that saves or returns the data you need.

3. Take filenames and subfolders from the server's task response, not arbitrary user-supplied absolute paths.

Steps and checks

The sequence below is an editorial procedure based on the cited context, not a diagnosis already confirmed for your environment.

Step 1. Wait for a terminal result or query that prompt's history. On failure, report the error instead of interpreting empty outputs as an indefinitely queued task.

Step 2. Traverse actual outputs for supported node types; do not assume a fixed numeric ID always belongs to SaveImage.

Step 3. Preserve filename, subfolder and type in /view requests, encoding them with URLSearchParams rather than manual concatenation.

Step 4. Associate the result with its task and validate response type/length. Explain expired temporary files rather than polling without a bound.

Commands and request examples

Use the environment and shell identified above. Paths and variables are examples to adapt; these commands/snippets were not executed for your machine.

const query = new URLSearchParams({
  filename: item.filename,
  subfolder: item.subfolder ?? "",
  type: item.type ?? "output",
});
const fileUrl = `${COMFY_BASE_URL}/view?${query}`;

Completion check

The client receives the correct task's artifact with a traceable output node/category, even across concurrent requests.

Limitations and cautions

Video and custom output schemas need explicit handling. A public integration must not permit arbitrary server-file reads through path parameters.

Original sources

• ComfyUI Server API routes — original record checked 2026-09-21.
• ComfyUI execution messages — original record checked 2026-09-21.

Localization prepared: 2026-09-22. The source-check dates above were inherited from the existing article; this translation does not claim they were all rechecked today. No GPU run, minimum-memory measurement or runtime guarantee is supplied.

Related troubleshooting and guides

• WebSocket connects but no result arrives: track prompt-specific terminal states
• Queue finishes quickly but no new file appears: check cache and output location