Port from nearai/ironclaw#2304: Telegram's 4096 character limit is
measured in UTF-16 code units, not Unicode codepoints. Characters
outside the Basic Multilingual Plane (emoji like 😀, CJK Extension B,
musical symbols) are surrogate pairs: 1 Python char but 2 UTF-16 units.
Previously, truncate_message() used Python's len() which counts
codepoints. This could produce chunks exceeding Telegram's actual limit
when messages contain many astral-plane characters.
Changes:
- Add utf16_len() helper and _prefix_within_utf16_limit() for
UTF-16-aware string measurement and truncation
- Add _custom_unit_to_cp() binary-search helper that maps a custom-unit
budget to the largest safe codepoint slice position
- Update truncate_message() to accept optional len_fn parameter
- Telegram adapter now passes len_fn=utf16_len when splitting messages
- Fix fallback truncation in Telegram error handler to use
_prefix_within_utf16_limit instead of codepoint slicing
- Update send_message_tool.py to use utf16_len for Telegram platform
- Add comprehensive tests: utf16_len, _prefix_within_utf16_limit,
truncate_message with len_fn (emoji splitting, content preservation,
code block handling)
- Update mock lambdas in reply_mode tests to accept **kw for len_fn
* feat(telegram): auto-discover fallback IPs via DoH when api.telegram.org is unreachable
On some networks (university, corporate), api.telegram.org resolves to a
valid Telegram IP that is unreachable due to routing/firewall rules. A
different IP in the same Telegram-owned 149.154.160.0/20 block works fine.
This adds automatic fallback IP discovery at connect time:
1. Query Google and Cloudflare DNS-over-HTTPS for api.telegram.org A records
2. Exclude the system-DNS IP (the unreachable one), use the rest as fallbacks
3. If DoH is also blocked, fall back to a seed list (149.154.167.220)
4. TelegramFallbackTransport tries primary first, sticks to whichever works
No configuration needed — works automatically. TELEGRAM_FALLBACK_IPS env var
still available as manual override. Zero impact on healthy networks (primary
path succeeds on first attempt, fallback never exercised).
No new dependencies (uses httpx already in deps + stdlib socket).
* fix: share transport instance and downgrade seed fallback log to info
- Use single TelegramFallbackTransport shared between request and
get_updates_request so sticky IP is shared across polling and API calls
- Keep separate HTTPXRequest instances (different timeout settings)
- Downgrade "using seed fallback IPs" from warning to info to avoid
noisy logs on healthy networks
* fix: add telegram.request mock and discovery fixture to remaining test files
The original PR missed test_dm_topics.py and
test_telegram_network_reconnect.py — both need the telegram.request
mock module. The reconnect test also needs _no_auto_discovery since
_handle_polling_network_error calls connect() which now invokes
discover_fallback_ips().
---------
Co-authored-by: Mohan Qiao <Gavin-Qiao@users.noreply.github.com>
Add reply_to_mode setting (off/first/all) to control whether Telegram
replies quote/thread to the user's original message.
- 'off': Never thread replies (no quote bubble)
- 'first': Only first chunk threads to user's message (default, preserves existing behavior)
- 'all': All chunks in multi-part replies thread to user's message
Configurable via:
- reply_to_mode in platform config (gateway config YAML)
- TELEGRAM_REPLY_TO_MODE env var
Based on PR #855 by raulvidis.
