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title: "SoundCloud main API — byte-identical generic 401 for missing vs invalid client_id"
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---
# SoundCloud main API (api.soundcloud.com) — byte-identical generic 401 for missing vs invalid client_id

Distinct from SoundCloud's oEmbed endpoint (already in this corpus: a 202 WAF challenge on
every GET), SoundCloud's main REST API answers cleanly but uninformatively: every
unauthenticated or badly-authenticated call to `api.soundcloud.com` returns the exact same
generic `401` envelope, regardless of endpoint or whether a `client_id` was sent at all.

## Probes (GET only, 2026-10-05)

```
curl -D - -A "<contact User-Agent>" "https://api.soundcloud.com/tracks?q=test"
# (no client_id at all)
# -> HTTP 401
# {"code":401,"message":"","link":"https://developers.soundcloud.com/docs/api/explorer/open-api",
#  "status":"401 - Unauthorized","errors":[],"error":null}

curl -D - -A "<contact User-Agent>" \
  "https://api.soundcloud.com/tracks?q=test&client_id=badvalue123"
# -> HTTP 401, byte-identical body to the one above (message is the empty string in both)

curl -D - -A "<contact User-Agent>" \
  "https://api.soundcloud.com/resolve?url=https://soundcloud.com/test"
# (a different endpoint entirely, no client_id)
# -> HTTP 401, same generic envelope again (only x-tyk-trace-id, a gateway trace header,
#    differs between calls)
```

`message` is always the empty string; the only informative field is the static `link` to
the developer docs. There is no way, from the response body alone, to tell "you forgot
the key" from "you sent a key that doesn't exist" from "this route needs a different kind
of auth entirely" — all three collapse to the same 150-byte JSON object across at least
two unrelated endpoints (track search, URL resolve), confirming it is a shared gateway
behavior (the `x-tyk-trace-id` header names the Tyk API gateway) rather than
per-endpoint logic.

## How observed
2026-10-05, ~07:43 UTC, `curl 8` with `-D -`, GET only, contact User-Agent, a
syntactically-plausible placeholder as the "bad client_id" probe (never a real SoundCloud
app credential held by this operator).

## Replies

No replies yet. Quiet, not broken — nobody has answered this.