- If `requireMention=false`, Telegram privacy mode must allow full visibility: BotFather `/setprivacy` -> Disable, then remove + re-add the bot to the group.
- `apus channels status` warns when config expects unmentioned group messages.
- `apus channels status --probe` checks explicit numeric group IDs; membership cannot be checked for the wildcard `"*"`.
- Quick session test: `/activation always`.

- When `channels.telegram.groups` exists, the group must be listed (or include `"*"`).
- Verify bot membership in the group.
- Review `apus logs --follow` for skip reasons.

- Authorize your sender identity (pairing and/or numeric `allowFrom`); command authorization still applies even when group policy is `open`.
- `setMyCommands failed` with `BOT_COMMANDS_TOO_MUCH` means the native menu has too many entries; reduce plugin/skill/custom commands or disable native menus.
- `deleteMyCommands` / `setMyCommands` startup calls and `sendChatAction` typing calls are bounded and retry once through Telegram's transport fallback on request timeout. Persistent network/fetch errors usually mean DNS/HTTPS to `api.telegram.org` is unreachable.

- `getMe returned 401` is a Telegram auth failure for the configured bot token. Re-copy or regenerate the token in BotFather, then update `channels.telegram.botToken`, `tokenFile`, `accounts.<id>.botToken`, or `TELEGRAM_BOT_TOKEN` (default account).
- `deleteWebhook 401 Unauthorized` during startup is also an auth failure; treating it as "no webhook exists" would only defer the same bad-token failure to a later API call.

The `Node 22+` references below describe Node networking behavior, not Apus's
supported runtime versions. See [Node.js](/install/node) for current requirements.

- Node 22+ with a custom fetch/proxy can trigger immediate abort behavior if `AbortSignal` types mismatch.
- Some hosts resolve `api.telegram.org` to IPv6 first; broken IPv6 egress causes intermittent API failures.
- Logs with `TypeError: fetch failed` or `Network request for 'getUpdates' failed!` are retried as recoverable network errors.
- During polling startup, Apus reuses the successful startup `getMe` check for grammY so the runner does not need a second `getMe` before the first `getUpdates`.
- If `deleteWebhook` fails with a transient network error during polling startup, Apus continues into long polling instead of making another pre-poll control-plane call. A still-active webhook then surfaces as a `getUpdates` conflict; Apus rebuilds the transport and retries webhook cleanup.
- `Polling stall detected` in logs means Apus restarts polling and rebuilds the transport after 120 seconds without completed long-poll liveness by default.
- `apus channels status --probe` and `apus doctor` warn when a running polling account has not completed `getUpdates` after startup grace, a running webhook account has not completed `setWebhook` after startup grace, or the last successful polling transport activity is stale.
- Telegram honors process proxy env for Bot API transport: `HTTP_PROXY`, `HTTPS_PROXY`, `ALL_PROXY`, and lowercase variants. `NO_PROXY` / `no_proxy` can still bypass `api.telegram.org`.
- If `APUS_PROXY_URL` is set for a service environment and no standard proxy env is present, Telegram uses that URL for Bot API transport too.
- If text works but attachments fail with `getaddrinfo EAI_AGAIN` or `ENOTFOUND`, bare proxy environment variables still leave media downloads subject to local DNS checks. Set `channels.telegram.proxy` to your trusted HTTP(S) or SOCKS5 proxy so it resolves media hostnames, or configure a [managed network proxy](/security/network-proxy). The proxy endpoint itself must remain locally resolvable and reachable. `dangerouslyAllowPrivateNetwork` does not fix missing DNS.
- On VPS hosts with unstable direct egress/TLS, route Telegram API calls through a proxy:

channels:
  telegram:
    proxy: socks5://<user>:<password>@proxy-host:1080

- Telegram DNS result order honors `APUS_TELEGRAM_DNS_RESULT_ORDER`, then `channels.telegram.network.dnsResultOrder`, then the process default, falling back to `ipv4first` if none applies. With `ipv4first`, Telegram disables address-family racing by default so an unreachable IPv6 route cannot interfere with the preferred IPv4 connection. `verbatim` keeps address-family selection enabled with a 300 ms attempt timeout, except on WSL2. Explicit `network.autoSelectFamily` or its environment overrides take precedence.
- On dual-stack hosts with broken IPv6, set `channels.telegram.network.dnsResultOrder: "ipv4first"`; no `NODE_OPTIONS` change is needed. Connection failures proven to occur before sending remain retryable; timeouts after sending remain ambiguous to avoid duplicate replies.
- On WSL2, or when IPv4-only behavior works better, force family selection:

channels:
  telegram:
    network:
      autoSelectFamily: false

- RFC 2544 benchmark-range answers (`198.18.0.0/15`) are already allowed for Telegram media downloads by default. If a trusted fake-IP or transparent proxy rewrites `api.telegram.org` to some other private/internal/special-use address during media downloads, opt in to the Telegram-only bypass:

channels:
  telegram:
    network:
      dangerouslyAllowPrivateNetwork: true

- The same opt-in is available per account at `channels.telegram.accounts.<accountId>.network.dangerouslyAllowPrivateNetwork`.
- If your proxy resolves Telegram media hosts into `198.18.x.x`, leave the dangerous flag off first — that range is already allowed by default.

  `channels.telegram.network.dangerouslyAllowPrivateNetwork` weakens Telegram media SSRF protections. Use it only for trusted operator-controlled proxy environments (Clash, Mihomo, Surge fake-IP routing) that synthesize private or special-use answers outside the RFC 2544 benchmark range. Leave it off for normal public internet Telegram access.

- Temporary environment overrides: `APUS_TELEGRAM_DISABLE_AUTO_SELECT_FAMILY=1`, `APUS_TELEGRAM_ENABLE_AUTO_SELECT_FAMILY=1`, `APUS_TELEGRAM_DNS_RESULT_ORDER=ipv4first`.
- Validate DNS answers:

dig +short api.telegram.org A
dig +short api.telegram.org AAAA