hermes-agent/gateway/stream_consumer.py
Siddharth Balyan d38b73fa57
fix(matrix): E2EE and migration bugfixes (#10860)
* - make buffered streaming
- fix path naming to expand `~` for agent.
- fix stripping of matrix ID to not remove other mentions / localports.

* fix(matrix): register MembershipEventDispatcher for invite auto-join

The mautrix migration (#7518) broke auto-join because InternalEventType.INVITE
events are only dispatched when MembershipEventDispatcher is registered on the
client. Without it, _on_invite is dead code and the bot silently ignores all
room invites.

Closes #10094
Closes #10725
Refs: PR #10135 (digging-airfare-4u), PR #10732 (fxfitz)

* fix(matrix): preserve _joined_rooms reference for CryptoStateStore

connect() reassigned self._joined_rooms = set(...) after initial sync,
orphaning the reference captured by _CryptoStateStore at init time.
find_shared_rooms() returned [] forever, breaking Megolm session rotation
on membership changes.

Mutate in place with clear() + update() so the CryptoStateStore reference
stays valid.

Refs #8174, PR #8215

* fix(matrix): remove dual ROOM_ENCRYPTED handler to fix dedup race

mautrix auto-registers DecryptionDispatcher when client.crypto is set.
The adapter also registered _on_encrypted_event for the same event type.
_on_encrypted_event had zero awaits and won the race to mark event IDs
in the dedup set, causing _on_room_message to drop successfully decrypted
events from DecryptionDispatcher. The retry loop masked this by re-decrypting
every message ~4 seconds later.

Remove _on_encrypted_event entirely. DecryptionDispatcher handles decryption;
genuinely undecryptable events are logged by mautrix and retried on next
key exchange.

Refs #8174, PR #8215

* fix(matrix): re-verify device keys after share_keys() upload

Matrix homeservers treat ed25519 identity keys as immutable per device.
share_keys() can return 200 but silently ignore new keys if the device
already exists with different identity keys. The bot would proceed with
shared=True while peers encrypt to the old (unreachable) keys.

Now re-queries the server after share_keys() and fails closed if keys
don't match, with an actionable error message.

Refs #8174, PR #8215

* fix(matrix): encrypt outbound attachments in E2EE rooms

_upload_and_send() uploaded raw bytes and used the 'url' key for all
rooms. In E2EE rooms, media must be encrypted client-side with
encrypt_attachment(), the ciphertext uploaded, and the 'file' key
(with key/iv/hashes) used instead of 'url'.

Now detects encrypted rooms via state_store.is_encrypted() and
branches to the encrypted upload path.

Refs: PR #9822 (charles-brooks)

* fix(matrix): add stop_typing to clear typing indicator after response

The adapter set a 30-second typing timeout but never cleared it.
The base class stop_typing() is a no-op, so the typing indicator
lingered for up to 30 seconds after each response.

Closes #6016
Refs: PR #6020 (r266-tech)

* fix(matrix): cache all media types locally, not just photos/voice

should_cache_locally only covered PHOTO, VOICE, and encrypted media.
Unencrypted audio/video/documents in plaintext rooms were passed as MXC
URLs that require authentication the agent doesn't have, resulting
in 401 errors.

Refs #3487, #3806

* fix(matrix): detect stale OTK conflict on startup and fail closed

When crypto state is wiped but the same device ID is reused, the
homeserver may still hold one-time keys signed with the previous
identity key. Identity key re-upload succeeds but OTK uploads fail
with "already exists" and a signature mismatch. Peers cannot
establish new Olm sessions, so all new messages are undecryptable.

Now proactively flushes OTKs via share_keys() during connect() and
catches the "already exists" error with an actionable log message
telling the operator to purge the device from the homeserver or
generate a fresh device ID.

Also documents the crypto store recovery procedure in the Matrix
setup guide.

Refs #8174

* docs(matrix): improve crypto recovery docs per review

- Put easy path (fresh access token) first, manual purge second
- URL-encode user ID in Synapse admin API example
- Note that device deletion may invalidate the access token
- Add "stop Synapse first" caveat for direct SQLite approach
- Mention the fail-closed startup detection behavior
- Add back-reference from upgrade section to OTK warning

* refactor(matrix): cleanup from code review

- Extract _extract_server_ed25519() and _reverify_keys_after_upload()
  to deduplicate the re-verification block (was copy-pasted in two
  places, three copies of ed25519 key extraction total)
- Remove dead code: _pending_megolm, _retry_pending_decryptions,
  _MAX_PENDING_EVENTS, _PENDING_EVENT_TTL — all orphaned after
  removing _on_encrypted_event
- Remove tautological TestMediaCacheGate (tested its own predicate,
  not production code)
- Remove dead TestMatrixMegolmEventHandling and
  TestMatrixRetryPendingDecryptions (tested removed methods)
- Merge duplicate TestMatrixStopTyping into TestMatrixTypingIndicator
- Trim comment to just the "why"
2026-04-17 04:03:02 +05:30

761 lines
34 KiB
Python

"""Gateway streaming consumer — bridges sync agent callbacks to async platform delivery.
The agent fires stream_delta_callback(text) synchronously from its worker thread.
GatewayStreamConsumer:
1. Receives deltas via on_delta() (thread-safe, sync)
2. Queues them to an asyncio task via queue.Queue
3. The async run() task buffers, rate-limits, and progressively edits
a single message on the target platform
Design: Uses the edit transport (send initial message, then editMessageText).
This is universally supported across Telegram, Discord, and Slack.
Credit: jobless0x (#774, #1312), OutThisLife (#798), clicksingh (#697).
"""
from __future__ import annotations
import asyncio
import logging
import queue
import re
import time
from dataclasses import dataclass
from typing import Any, Optional
logger = logging.getLogger("gateway.stream_consumer")
# Sentinel to signal the stream is complete
_DONE = object()
# Sentinel to signal a tool boundary — finalize current message and start a
# new one so that subsequent text appears below tool progress messages.
_NEW_SEGMENT = object()
# Queue marker for a completed assistant commentary message emitted between
# API/tool iterations (for example: "I'll inspect the repo first.").
_COMMENTARY = object()
@dataclass
class StreamConsumerConfig:
"""Runtime config for a single stream consumer instance."""
edit_interval: float = 1.0
buffer_threshold: int = 40
cursor: str = ""
buffer_only: bool = False
class GatewayStreamConsumer:
"""Async consumer that progressively edits a platform message with streamed tokens.
Usage::
consumer = GatewayStreamConsumer(adapter, chat_id, config, metadata=metadata)
# Pass consumer.on_delta as stream_delta_callback to AIAgent
agent = AIAgent(..., stream_delta_callback=consumer.on_delta)
# Start the consumer as an asyncio task
task = asyncio.create_task(consumer.run())
# ... run agent in thread pool ...
consumer.finish() # signal completion
await task # wait for final edit
"""
# After this many consecutive flood-control failures, permanently disable
# progressive edits for the remainder of the stream.
_MAX_FLOOD_STRIKES = 3
# Reasoning/thinking tags that models emit inline in content.
# Must stay in sync with cli.py _OPEN_TAGS/_CLOSE_TAGS and
# run_agent.py _strip_think_blocks() tag variants.
_OPEN_THINK_TAGS = (
"<REASONING_SCRATCHPAD>", "<think>", "<reasoning>",
"<THINKING>", "<thinking>", "<thought>",
)
_CLOSE_THINK_TAGS = (
"</REASONING_SCRATCHPAD>", "</think>", "</reasoning>",
"</THINKING>", "</thinking>", "</thought>",
)
def __init__(
self,
adapter: Any,
chat_id: str,
config: Optional[StreamConsumerConfig] = None,
metadata: Optional[dict] = None,
):
self.adapter = adapter
self.chat_id = chat_id
self.cfg = config or StreamConsumerConfig()
self.metadata = metadata
self._queue: queue.Queue = queue.Queue()
self._accumulated = ""
self._message_id: Optional[str] = None
self._already_sent = False
self._edit_supported = True # Disabled when progressive edits are no longer usable
self._last_edit_time = 0.0
self._last_sent_text = "" # Track last-sent text to skip redundant edits
self._fallback_final_send = False
self._fallback_prefix = ""
self._flood_strikes = 0 # Consecutive flood-control edit failures
self._current_edit_interval = self.cfg.edit_interval # Adaptive backoff
self._final_response_sent = False
# Think-block filter state (mirrors CLI's _stream_delta tag suppression)
self._in_think_block = False
self._think_buffer = ""
@property
def already_sent(self) -> bool:
"""True if at least one message was sent or edited during the run."""
return self._already_sent
@property
def final_response_sent(self) -> bool:
"""True when the stream consumer delivered the final assistant reply."""
return self._final_response_sent
def on_segment_break(self) -> None:
"""Finalize the current stream segment and start a fresh message."""
self._queue.put(_NEW_SEGMENT)
def on_commentary(self, text: str) -> None:
"""Queue a completed interim assistant commentary message."""
if text:
self._queue.put((_COMMENTARY, text))
def _reset_segment_state(self, *, preserve_no_edit: bool = False) -> None:
if preserve_no_edit and self._message_id == "__no_edit__":
return
self._message_id = None
self._accumulated = ""
self._last_sent_text = ""
self._fallback_final_send = False
self._fallback_prefix = ""
def on_delta(self, text: str) -> None:
"""Thread-safe callback — called from the agent's worker thread.
When *text* is ``None``, signals a tool boundary: the current message
is finalized and subsequent text will be sent as a new message so it
appears below any tool-progress messages the gateway sent in between.
"""
if text:
self._queue.put(text)
elif text is None:
self.on_segment_break()
def finish(self) -> None:
"""Signal that the stream is complete."""
self._queue.put(_DONE)
# ── Think-block filtering ────────────────────────────────────────
# Models like MiniMax emit inline <think>...</think> blocks in their
# content. The CLI's _stream_delta suppresses these via a state
# machine; we do the same here so gateway users never see raw
# reasoning tags. The agent also strips them from the final
# response (run_agent.py _strip_think_blocks), but the stream
# consumer sends intermediate edits before that stripping happens.
def _filter_and_accumulate(self, text: str) -> None:
"""Add a text delta to the accumulated buffer, suppressing think blocks.
Uses a state machine that tracks whether we are inside a
reasoning/thinking block. Text inside such blocks is silently
discarded. Partial tags at buffer boundaries are held back in
``_think_buffer`` until enough characters arrive to decide.
"""
buf = self._think_buffer + text
self._think_buffer = ""
while buf:
if self._in_think_block:
# Look for the earliest closing tag
best_idx = -1
best_len = 0
for tag in self._CLOSE_THINK_TAGS:
idx = buf.find(tag)
if idx != -1 and (best_idx == -1 or idx < best_idx):
best_idx = idx
best_len = len(tag)
if best_len:
# Found closing tag — discard block, process remainder
self._in_think_block = False
buf = buf[best_idx + best_len:]
else:
# No closing tag yet — hold tail that could be a
# partial closing tag prefix, discard the rest.
max_tag = max(len(t) for t in self._CLOSE_THINK_TAGS)
self._think_buffer = buf[-max_tag:] if len(buf) > max_tag else buf
return
else:
# Look for earliest opening tag at a block boundary
# (start of text / preceded by newline + optional whitespace).
# This prevents false positives when models *mention* tags
# in prose (e.g. "the <think> tag is used for…").
best_idx = -1
best_len = 0
for tag in self._OPEN_THINK_TAGS:
search_start = 0
while True:
idx = buf.find(tag, search_start)
if idx == -1:
break
# Block-boundary check (mirrors cli.py logic)
if idx == 0:
is_boundary = (
not self._accumulated
or self._accumulated.endswith("\n")
)
else:
preceding = buf[:idx]
last_nl = preceding.rfind("\n")
if last_nl == -1:
is_boundary = (
(not self._accumulated
or self._accumulated.endswith("\n"))
and preceding.strip() == ""
)
else:
is_boundary = preceding[last_nl + 1:].strip() == ""
if is_boundary and (best_idx == -1 or idx < best_idx):
best_idx = idx
best_len = len(tag)
break # first boundary hit for this tag is enough
search_start = idx + 1
if best_len:
# Emit text before the tag, enter think block
self._accumulated += buf[:best_idx]
self._in_think_block = True
buf = buf[best_idx + best_len:]
else:
# No opening tag — check for a partial tag at the tail
held_back = 0
for tag in self._OPEN_THINK_TAGS:
for i in range(1, len(tag)):
if buf.endswith(tag[:i]) and i > held_back:
held_back = i
if held_back:
self._accumulated += buf[:-held_back]
self._think_buffer = buf[-held_back:]
else:
self._accumulated += buf
return
def _flush_think_buffer(self) -> None:
"""Flush any held-back partial-tag buffer into accumulated text.
Called when the stream ends (got_done) so that partial text that
was held back waiting for a possible opening tag is not lost.
"""
if self._think_buffer and not self._in_think_block:
self._accumulated += self._think_buffer
self._think_buffer = ""
async def run(self) -> None:
"""Async task that drains the queue and edits the platform message."""
# Platform message length limit — leave room for cursor + formatting
_raw_limit = getattr(self.adapter, "MAX_MESSAGE_LENGTH", 4096)
_safe_limit = max(500, _raw_limit - len(self.cfg.cursor) - 100)
try:
while True:
# Drain all available items from the queue
got_done = False
got_segment_break = False
commentary_text = None
while True:
try:
item = self._queue.get_nowait()
if item is _DONE:
got_done = True
break
if item is _NEW_SEGMENT:
got_segment_break = True
break
if isinstance(item, tuple) and len(item) == 2 and item[0] is _COMMENTARY:
commentary_text = item[1]
break
self._filter_and_accumulate(item)
except queue.Empty:
break
# Flush any held-back partial-tag buffer on stream end
# so trailing text that was waiting for a potential open
# tag is not lost.
if got_done:
self._flush_think_buffer()
# Decide whether to flush an edit
now = time.monotonic()
elapsed = now - self._last_edit_time
should_edit = (
got_done
or got_segment_break
or commentary_text is not None
)
if not self.cfg.buffer_only:
should_edit = should_edit or (
(elapsed >= self._current_edit_interval
and self._accumulated)
or len(self._accumulated) >= self.cfg.buffer_threshold
)
current_update_visible = False
if should_edit and self._accumulated:
# Split overflow: if accumulated text exceeds the platform
# limit, split into properly sized chunks.
if (
len(self._accumulated) > _safe_limit
and self._message_id is None
):
# No existing message to edit (first message or after a
# segment break). Use truncate_message — the same
# helper the non-streaming path uses — to split with
# proper word/code-fence boundaries and chunk
# indicators like "(1/2)".
chunks = self.adapter.truncate_message(
self._accumulated, _safe_limit
)
for chunk in chunks:
await self._send_new_chunk(chunk, self._message_id)
self._accumulated = ""
self._last_sent_text = ""
self._last_edit_time = time.monotonic()
if got_done:
self._final_response_sent = self._already_sent
return
if got_segment_break:
self._message_id = None
self._fallback_final_send = False
self._fallback_prefix = ""
continue
# Existing message: edit it with the first chunk, then
# start a new message for the overflow remainder.
while (
len(self._accumulated) > _safe_limit
and self._message_id is not None
and self._edit_supported
):
split_at = self._accumulated.rfind("\n", 0, _safe_limit)
if split_at < _safe_limit // 2:
split_at = _safe_limit
chunk = self._accumulated[:split_at]
ok = await self._send_or_edit(chunk)
if self._fallback_final_send or not ok:
# Edit failed (or backed off due to flood control)
# while attempting to split an oversized message.
# Keep the full accumulated text intact so the
# fallback final-send path can deliver the remaining
# continuation without dropping content.
break
self._accumulated = self._accumulated[split_at:].lstrip("\n")
self._message_id = None
self._last_sent_text = ""
display_text = self._accumulated
if not got_done and not got_segment_break and commentary_text is None:
display_text += self.cfg.cursor
current_update_visible = await self._send_or_edit(display_text)
self._last_edit_time = time.monotonic()
if got_done:
# Final edit without cursor. If progressive editing failed
# mid-stream, send a single continuation/fallback message
# here instead of letting the base gateway path send the
# full response again.
if self._accumulated:
if self._fallback_final_send:
await self._send_fallback_final(self._accumulated)
elif current_update_visible:
self._final_response_sent = True
elif self._message_id:
self._final_response_sent = await self._send_or_edit(self._accumulated)
elif not self._already_sent:
self._final_response_sent = await self._send_or_edit(self._accumulated)
return
if commentary_text is not None:
self._reset_segment_state()
await self._send_commentary(commentary_text)
self._last_edit_time = time.monotonic()
self._reset_segment_state()
# Tool boundary: reset message state so the next text chunk
# creates a fresh message below any tool-progress messages.
#
# Exception: when _message_id is "__no_edit__" the platform
# never returned a real message ID (e.g. Signal, webhook with
# github_comment delivery). Resetting to None would re-enter
# the "first send" path on every tool boundary and post one
# platform message per tool call — that is what caused 155
# comments under a single PR. Instead, preserve the sentinel
# so the full continuation is delivered once via
# _send_fallback_final.
# (When editing fails mid-stream due to flood control the id is
# a real string like "msg_1", not "__no_edit__", so that case
# still resets and creates a fresh segment as intended.)
if got_segment_break:
self._reset_segment_state(preserve_no_edit=True)
await asyncio.sleep(0.05) # Small yield to not busy-loop
except asyncio.CancelledError:
# Best-effort final edit on cancellation
_best_effort_ok = False
if self._accumulated and self._message_id:
try:
_best_effort_ok = bool(await self._send_or_edit(self._accumulated))
except Exception:
pass
# Only confirm final delivery if the best-effort send above
# actually succeeded OR if the final response was already
# confirmed before we were cancelled. Previously this
# promoted any partial send (already_sent=True) to
# final_response_sent — which suppressed the gateway's
# fallback send even when only intermediate text (e.g.
# "Let me search…") had been delivered, not the real answer.
if _best_effort_ok and not self._final_response_sent:
self._final_response_sent = True
except Exception as e:
logger.error("Stream consumer error: %s", e)
# Pattern to strip MEDIA:<path> tags (including optional surrounding quotes).
# Matches the simple cleanup regex used by the non-streaming path in
# gateway/platforms/base.py for post-processing.
_MEDIA_RE = re.compile(r'''[`"']?MEDIA:\s*\S+[`"']?''')
@staticmethod
def _clean_for_display(text: str) -> str:
"""Strip MEDIA: directives and internal markers from text before display.
The streaming path delivers raw text chunks that may include
``MEDIA:<path>`` tags and ``[[audio_as_voice]]`` directives meant for
the platform adapter's post-processing. The actual media files are
delivered separately via ``_deliver_media_from_response()`` after the
stream finishes — we just need to hide the raw directives from the
user.
"""
if "MEDIA:" not in text and "[[audio_as_voice]]" not in text:
return text
cleaned = text.replace("[[audio_as_voice]]", "")
cleaned = GatewayStreamConsumer._MEDIA_RE.sub("", cleaned)
# Collapse excessive blank lines left behind by removed tags
cleaned = re.sub(r'\n{3,}', '\n\n', cleaned)
# Strip trailing whitespace/newlines but preserve leading content
return cleaned.rstrip()
async def _send_new_chunk(self, text: str, reply_to_id: Optional[str]) -> Optional[str]:
"""Send a new message chunk, optionally threaded to a previous message.
Returns the message_id so callers can thread subsequent chunks.
"""
text = self._clean_for_display(text)
if not text.strip():
return reply_to_id
try:
meta = dict(self.metadata) if self.metadata else {}
result = await self.adapter.send(
chat_id=self.chat_id,
content=text,
reply_to=reply_to_id,
metadata=meta,
)
if result.success and result.message_id:
self._message_id = str(result.message_id)
self._already_sent = True
self._last_sent_text = text
return str(result.message_id)
else:
self._edit_supported = False
return reply_to_id
except Exception as e:
logger.error("Stream send chunk error: %s", e)
return reply_to_id
def _visible_prefix(self) -> str:
"""Return the visible text already shown in the streamed message."""
prefix = self._last_sent_text or ""
if self.cfg.cursor and prefix.endswith(self.cfg.cursor):
prefix = prefix[:-len(self.cfg.cursor)]
return self._clean_for_display(prefix)
def _continuation_text(self, final_text: str) -> str:
"""Return only the part of final_text the user has not already seen."""
prefix = self._fallback_prefix or self._visible_prefix()
if prefix and final_text.startswith(prefix):
return final_text[len(prefix):].lstrip()
return final_text
@staticmethod
def _split_text_chunks(text: str, limit: int) -> list[str]:
"""Split text into reasonably sized chunks for fallback sends."""
if len(text) <= limit:
return [text]
chunks: list[str] = []
remaining = text
while len(remaining) > limit:
split_at = remaining.rfind("\n", 0, limit)
if split_at < limit // 2:
split_at = limit
chunks.append(remaining[:split_at])
remaining = remaining[split_at:].lstrip("\n")
if remaining:
chunks.append(remaining)
return chunks
async def _send_fallback_final(self, text: str) -> None:
"""Send the final continuation after streaming edits stop working.
Retries each chunk once on flood-control failures with a short delay.
"""
final_text = self._clean_for_display(text)
continuation = self._continuation_text(final_text)
self._fallback_final_send = False
if not continuation.strip():
# Nothing new to send — the visible partial already matches final text.
# BUT: if final_text itself has meaningful content (e.g. a timeout
# message after a long tool call), the prefix-based continuation
# calculation may wrongly conclude "already shown" because the
# streamed prefix was from a *previous* segment (before the tool
# boundary). In that case, send the full final_text as-is (#10807).
if final_text.strip() and final_text != self._visible_prefix():
continuation = final_text
else:
self._already_sent = True
self._final_response_sent = True
return
raw_limit = getattr(self.adapter, "MAX_MESSAGE_LENGTH", 4096)
safe_limit = max(500, raw_limit - 100)
chunks = self._split_text_chunks(continuation, safe_limit)
last_message_id: Optional[str] = None
last_successful_chunk = ""
sent_any_chunk = False
for chunk in chunks:
# Try sending with one retry on flood-control errors.
result = None
for attempt in range(2):
result = await self.adapter.send(
chat_id=self.chat_id,
content=chunk,
metadata=self.metadata,
)
if result.success:
break
if attempt == 0 and self._is_flood_error(result):
logger.debug(
"Flood control on fallback send, retrying in 3s"
)
await asyncio.sleep(3.0)
else:
break # non-flood error or second attempt failed
if not result or not result.success:
if sent_any_chunk:
# Some continuation text already reached the user. Suppress
# the base gateway final-send path so we don't resend the
# full response and create another duplicate.
self._already_sent = True
self._final_response_sent = True
self._message_id = last_message_id
self._last_sent_text = last_successful_chunk
self._fallback_prefix = ""
return
# No fallback chunk reached the user — allow the normal gateway
# final-send path to try one more time.
self._already_sent = False
self._message_id = None
self._last_sent_text = ""
self._fallback_prefix = ""
return
sent_any_chunk = True
last_successful_chunk = chunk
last_message_id = result.message_id or last_message_id
self._message_id = last_message_id
self._already_sent = True
self._final_response_sent = True
self._last_sent_text = chunks[-1]
self._fallback_prefix = ""
def _is_flood_error(self, result) -> bool:
"""Check if a SendResult failure is due to flood control / rate limiting."""
err = getattr(result, "error", "") or ""
err_lower = err.lower()
return "flood" in err_lower or "retry after" in err_lower or "rate" in err_lower
async def _try_strip_cursor(self) -> None:
"""Best-effort edit to remove the cursor from the last visible message.
Called when entering fallback mode so the user doesn't see a stuck
cursor (▉) in the partial message.
"""
if not self._message_id or self._message_id == "__no_edit__":
return
prefix = self._visible_prefix()
if not prefix or not prefix.strip():
return
try:
await self.adapter.edit_message(
chat_id=self.chat_id,
message_id=self._message_id,
content=prefix,
)
self._last_sent_text = prefix
except Exception:
pass # best-effort — don't let this block the fallback path
async def _send_commentary(self, text: str) -> bool:
"""Send a completed interim assistant commentary message."""
text = self._clean_for_display(text)
if not text.strip():
return False
try:
result = await self.adapter.send(
chat_id=self.chat_id,
content=text,
metadata=self.metadata,
)
# Note: do NOT set _already_sent = True here.
# Commentary messages are interim status updates (e.g. "Using browser
# tool..."), not the final response. Setting already_sent would cause
# the final response to be incorrectly suppressed when there are
# multiple tool calls. See: https://github.com/NousResearch/hermes-agent/issues/10454
return result.success
except Exception as e:
logger.error("Commentary send error: %s", e)
return False
async def _send_or_edit(self, text: str) -> bool:
"""Send or edit the streaming message.
Returns True if the text was successfully delivered (sent or edited),
False otherwise. Callers like the overflow split loop use this to
decide whether to advance past the delivered chunk.
"""
# Strip MEDIA: directives so they don't appear as visible text.
# Media files are delivered as native attachments after the stream
# finishes (via _deliver_media_from_response in gateway/run.py).
text = self._clean_for_display(text)
# A bare streaming cursor is not meaningful user-visible content and
# can render as a stray tofu/white-box message on some clients.
visible_without_cursor = text
if self.cfg.cursor:
visible_without_cursor = visible_without_cursor.replace(self.cfg.cursor, "")
_visible_stripped = visible_without_cursor.strip()
if not _visible_stripped:
return True # cursor-only / whitespace-only update
if not text.strip():
return True # nothing to send is "success"
# Guard: do not create a brand-new standalone message when the only
# visible content is a handful of characters alongside the streaming
# cursor. During rapid tool-calling the model often emits 1-2 tokens
# before switching to tool calls; the resulting "X ▉" message risks
# leaving the cursor permanently visible if the follow-up edit (to
# strip the cursor on segment break) is rate-limited by the platform.
# This was reported on Telegram, Matrix, and other clients where the
# ▉ block character renders as a visible white box ("tofu").
# Existing messages (edits) are unaffected — only first sends gated.
_MIN_NEW_MSG_CHARS = 4
if (self._message_id is None
and self.cfg.cursor
and self.cfg.cursor in text
and len(_visible_stripped) < _MIN_NEW_MSG_CHARS):
return True # too short for a standalone message — accumulate more
try:
if self._message_id is not None:
if self._edit_supported:
# Skip if text is identical to what we last sent
if text == self._last_sent_text:
return True
# Edit existing message
result = await self.adapter.edit_message(
chat_id=self.chat_id,
message_id=self._message_id,
content=text,
)
if result.success:
self._already_sent = True
self._last_sent_text = text
# Successful edit — reset flood strike counter
self._flood_strikes = 0
return True
else:
# Edit failed. If this looks like flood control / rate
# limiting, use adaptive backoff: double the edit interval
# and retry on the next cycle. Only permanently disable
# edits after _MAX_FLOOD_STRIKES consecutive failures.
if self._is_flood_error(result):
self._flood_strikes += 1
self._current_edit_interval = min(
self._current_edit_interval * 2, 10.0,
)
logger.debug(
"Flood control on edit (strike %d/%d), "
"backoff interval → %.1fs",
self._flood_strikes,
self._MAX_FLOOD_STRIKES,
self._current_edit_interval,
)
if self._flood_strikes < self._MAX_FLOOD_STRIKES:
# Don't disable edits yet — just slow down.
# Update _last_edit_time so the next edit
# respects the new interval.
self._last_edit_time = time.monotonic()
return False
# Non-flood error OR flood strikes exhausted: enter
# fallback mode — send only the missing tail once the
# final response is available.
logger.debug(
"Edit failed (strikes=%d), entering fallback mode",
self._flood_strikes,
)
self._fallback_prefix = self._visible_prefix()
self._fallback_final_send = True
self._edit_supported = False
self._already_sent = True
# Best-effort: strip the cursor from the last visible
# message so the user doesn't see a stuck ▉.
await self._try_strip_cursor()
return False
else:
# Editing not supported — skip intermediate updates.
# The final response will be sent by the fallback path.
return False
else:
# First message — send new
result = await self.adapter.send(
chat_id=self.chat_id,
content=text,
metadata=self.metadata,
)
if result.success:
if result.message_id:
self._message_id = result.message_id
else:
self._edit_supported = False
self._already_sent = True
self._last_sent_text = text
if not result.message_id:
self._fallback_prefix = self._visible_prefix()
self._fallback_final_send = True
# Sentinel prevents re-entering the first-send path on
# every delta/tool boundary when platforms accept a
# message but do not return an editable message id.
self._message_id = "__no_edit__"
return True
else:
# Initial send failed — disable streaming for this session
self._edit_supported = False
return False
except Exception as e:
logger.error("Stream send/edit error: %s", e)
return False