meshcore-bot-firmware/patches/meshcore/0007-Prefix-bot-responses-with-request-token-for-inter-bo.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: cj-vana <cj@depth23.online>
Date: Sat, 16 May 2026 19:33:04 -0600
Subject: [PATCH 07/12] Prefix bot responses with request token for inter-bot
 suppression

Adds a 4-hex request token (low 16 bits of the request fingerprint) as a
leading "[XXXX] " prefix on every bot response. Two bots receiving the
same channel request compute the same fingerprint -> same token, so a
peer bot can correlate an observed response back to its own pending
response even when the response text differs (per-bot data like hop
count, SNR, recv time, etc.).

New FirmwareBot helpers:
- requestToken(BotFingerprint) -> uint16_t
- formatRequestToken(uint16_t, char[5])
- parseRequestTokenPrefix(text, len, *token, *prefix_len)
- prependRequestToken(request_fingerprint, text, text_len, buf_len, *new_len)

New ResponseCoordinator function:
- suppressByRequestToken(pending, count, token16) suppresses entries
  where (request_fingerprint.value & 0xFFFF) == token16

Wiring:
- MyMesh::enqueueBotResponse prepends the token to every queued response
- MyMesh::sendBotTraceText prepends the token to async trace results
- MyMesh::observeBotGroupResponse parses the token from incoming peer
  responses and suppresses matching pending responses, in addition to
  the existing response-fingerprint match (which still handles deterministic
  commands like ping->Pong where both bots produce identical text)

Fixes inter-bot duplication on #bot for ack/test/hello/status/roll/dice/
path/trace/tracer/stats/time/lora/id/neighbors observed on the Colorado
mesh when two bots both queued responses to the same command.
---
 examples/companion_radio/FirmwareBot.cpp      | 65 +++++++++++++++++++
 examples/companion_radio/FirmwareBot.h        |  5 ++
 examples/companion_radio/MyMesh.cpp           | 40 +++++++++---
 .../companion_radio/ResponseCoordinator.cpp   | 15 +++++
 .../companion_radio/ResponseCoordinator.h     |  1 +
 5 files changed, 118 insertions(+), 8 deletions(-)

diff --git a/examples/companion_radio/FirmwareBot.cpp b/examples/companion_radio/FirmwareBot.cpp
index 6aac8a1b..24c79e81 100644
--- a/examples/companion_radio/FirmwareBot.cpp
+++ b/examples/companion_radio/FirmwareBot.cpp
@@ -422,4 +422,69 @@ BotFingerprint responseFingerprintFor(const BotMessage& message, const char* res
   return fingerprint;
 }
 
+uint16_t requestToken(BotFingerprint request_fingerprint) {
+  // Take the low 16 bits of the request fingerprint. Two bots computing
+  // fingerprintFor() against the same request derive the same token, so
+  // a bot can recognise another bot's response to a request it also queued
+  // even when the response text differs (different hop count, SNR, recv time).
+  return (uint16_t)(request_fingerprint.value & 0xFFFFu);
+}
+
+void formatRequestToken(uint16_t token, char out[5]) {
+  if (!out) return;
+  static const char hex[] = "0123456789abcdef";
+  out[0] = hex[(token >> 12) & 0xF];
+  out[1] = hex[(token >> 8) & 0xF];
+  out[2] = hex[(token >> 4) & 0xF];
+  out[3] = hex[token & 0xF];
+  out[4] = 0;
+}
+
+static int hexNibble(char c) {
+  if (c >= '0' && c <= '9') return c - '0';
+  if (c >= 'a' && c <= 'f') return 10 + (c - 'a');
+  if (c >= 'A' && c <= 'F') return 10 + (c - 'A');
+  return -1;
+}
+
+bool parseRequestTokenPrefix(const char* text, size_t text_len, uint16_t* token, size_t* prefix_len) {
+  if (token) *token = 0;
+  if (prefix_len) *prefix_len = 0;
+  if (!text || text_len < 7) return false;            // "[XXXX] " = 7 chars minimum
+  if (text[0] != '[' || text[5] != ']' || text[6] != ' ') return false;
+  uint16_t value = 0;
+  for (int i = 0; i < 4; i++) {
+    int n = hexNibble(text[1 + i]);
+    if (n < 0) return false;
+    value = (uint16_t)((value << 4) | (uint16_t)n);
+  }
+  if (token) *token = value;
+  if (prefix_len) *prefix_len = 7;
+  return true;
+}
+
+BotWriteResult prependRequestToken(BotFingerprint request_fingerprint, char* text, size_t text_len, size_t buf_len,
+                                   size_t* new_len) {
+  if (new_len) *new_len = text_len;
+  if (!text || buf_len == 0) return BOT_WRITE_NO_SPACE;
+  if (text_len + 7 + 1 > buf_len) {
+    // No room for "[XXXX] " prefix + null terminator without dropping content.
+    return BOT_WRITE_NO_SPACE;
+  }
+  char hex[5];
+  formatRequestToken(requestToken(request_fingerprint), hex);
+  memmove(text + 7, text, text_len);
+  text[0] = '[';
+  text[1] = hex[0];
+  text[2] = hex[1];
+  text[3] = hex[2];
+  text[4] = hex[3];
+  text[5] = ']';
+  text[6] = ' ';
+  size_t total = text_len + 7;
+  if (total < buf_len) text[total] = 0;
+  if (new_len) *new_len = total;
+  return BOT_WRITE_OK;
+}
+
 }
diff --git a/examples/companion_radio/FirmwareBot.h b/examples/companion_radio/FirmwareBot.h
index 9eff340b..6e5cfd9a 100644
--- a/examples/companion_radio/FirmwareBot.h
+++ b/examples/companion_radio/FirmwareBot.h
@@ -20,6 +20,11 @@ BotWriteResult writeBotAdvertName(const char* node_name, char* output, size_t ou
 bool isBotAdvertName(const char* name, size_t name_len);
 BotFingerprint fingerprintFor(const BotMessage& message);
 BotFingerprint responseFingerprintFor(const BotMessage& message, const char* response_text, size_t response_text_len);
+uint16_t requestToken(BotFingerprint request_fingerprint);
+void formatRequestToken(uint16_t token, char out[5]);
+bool parseRequestTokenPrefix(const char* text, size_t text_len, uint16_t* token, size_t* prefix_len);
+BotWriteResult prependRequestToken(BotFingerprint request_fingerprint, char* text, size_t text_len, size_t buf_len,
+                                   size_t* new_len);
 BotCommandId commandIdForName(const char* name, size_t len);
 size_t maxResponseLenForChannel(BotChannelKind channel_kind);
 bool isCommandOnCooldown(const BotCommandCooldown* cooldowns, size_t cooldown_count, BotCommandId command_id,
diff --git a/examples/companion_radio/MyMesh.cpp b/examples/companion_radio/MyMesh.cpp
index 9209dd86..02339124 100644
--- a/examples/companion_radio/MyMesh.cpp
+++ b/examples/companion_radio/MyMesh.cpp
@@ -1209,6 +1209,11 @@ bool MyMesh::enqueueBotResponse(const BotMessage &message, const ContactInfo *di
   if (!botFormatResponseForChannel(message, text, text_len, pending->text, sizeof(pending->text), &pending->text_len)) {
     return false;
   }
+  // Prefix every bot response with the request token so peer bots can correlate
+  // their pending response to ours (their response text may differ from ours when
+  // the command includes per-bot data like hop count, SNR, recv time, etc.).
+  FirmwareBot::prependRequestToken(request_fingerprint, pending->text, pending->text_len, sizeof(pending->text),
+                                    &pending->text_len);
   pending->active = true;
   return true;
 }
@@ -1613,6 +1618,17 @@ BotFingerprint MyMesh::traceResponseFingerprintFor(const PendingBotTrace &pendin
 
 bool MyMesh::sendBotTraceText(const PendingBotTrace &pending, const char *text, size_t text_len,
                               BotFingerprint response_fingerprint, uint32_t now_millis) {
+  // Prefix with the request token so peer bots can correlate this trace result
+  // back to their own pending trace for the same request and suppress duplicates.
+  char tokened[BOT_MAX_RESPONSE_LEN + 1];
+  size_t tokened_len = text_len;
+  if (tokened_len > BOT_MAX_RESPONSE_LEN) tokened_len = BOT_MAX_RESPONSE_LEN;
+  if (tokened_len > 0) memcpy(tokened, text, tokened_len);
+  tokened[tokened_len] = 0;
+  FirmwareBot::prependRequestToken(pending.request_fingerprint, tokened, tokened_len, sizeof(tokened), &tokened_len);
+  const char *send_text = tokened;
+  size_t send_len = tokened_len;
+
   bool success = false;
   if (pending.direct) {
     ContactInfo *recipient = lookupContactByPubKey(pending.recipient_pub_key, PUB_KEY_SIZE);
@@ -1620,12 +1636,7 @@ bool MyMesh::sendBotTraceText(const PendingBotTrace &pending, const char *text,
       uint32_t expected_ack = 0;
       uint32_t est_timeout = 0;
       uint32_t timestamp = getRTCClock()->getCurrentTimeUnique();
-      char response[BOT_MAX_RESPONSE_LEN + 1];
-      size_t copy_len = text_len;
-      if (copy_len > BOT_MAX_RESPONSE_LEN) copy_len = BOT_MAX_RESPONSE_LEN;
-      if (copy_len > 0) memcpy(response, text, copy_len);
-      response[copy_len] = 0;
-      int result = sendMessage(*recipient, timestamp, 0, response, expected_ack, est_timeout);
+      int result = sendMessage(*recipient, timestamp, 0, send_text, expected_ack, est_timeout);
       success = result != MSG_SEND_FAILED;
       if (success && expected_ack) {
         expected_ack_table[next_ack_idx].msg_sent = _ms->getMillis();
@@ -1638,7 +1649,7 @@ bool MyMesh::sendBotTraceText(const PendingBotTrace &pending, const char *text,
     ChannelDetails channel;
     uint32_t timestamp = getRTCClock()->getCurrentTimeUnique();
     success = getChannel(pending.channel_idx, channel) &&
-              sendGroupMessage(timestamp, channel.channel, _prefs.node_name, text, text_len);
+              sendGroupMessage(timestamp, channel.channel, _prefs.node_name, send_text, send_len);
   }
 
   if (success) {
@@ -1744,6 +1755,19 @@ bool MyMesh::observeKnownBotResponse(const BotMessage &message, bool authoritati
 
 bool MyMesh::observeBotGroupResponse(const BotMessage &message) {
   if (!BotPolicy::isPrefixlessCommandAllowed(message.channel_kind)) return false;
+
+  // If the incoming channel message carries a request token from a peer bot,
+  // suppress our own pending response for that same request even when the
+  // response text differs (hop count, SNR, recv time, etc.).
+  uint16_t token = 0;
+  size_t token_prefix_len = 0;
+  bool token_suppressed = false;
+  if (FirmwareBot::parseRequestTokenPrefix(message.text, message.text_len, &token, &token_prefix_len)) {
+    if (ResponseCoordinator::suppressByRequestToken(bot_coordinator_pending, BOT_COORDINATOR_PENDING_SLOTS, token)) {
+      token_suppressed = true;
+    }
+  }
+
   BotFingerprint fingerprint = FirmwareBot::responseFingerprintFor(message, message.text, message.text_len);
   if (ResponseCoordinator::recentlySent(bot_coordinator_recent, BOT_COORDINATOR_RECENT_SLOTS, fingerprint, _ms->getMillis())) {
     return true;
@@ -1751,7 +1775,7 @@ bool MyMesh::observeBotGroupResponse(const BotMessage &message) {
   if (ResponseCoordinator::suppress(bot_coordinator_pending, BOT_COORDINATOR_PENDING_SLOTS, fingerprint)) {
     return true;
   }
-  return false;
+  return token_suppressed;
 }
 
 void MyMesh::recordBotObservation(const BotMessage &message, const ContactInfo *direct_recipient, uint8_t channel_idx) {
diff --git a/examples/companion_radio/ResponseCoordinator.cpp b/examples/companion_radio/ResponseCoordinator.cpp
index 7afdab24..3640f8b6 100644
--- a/examples/companion_radio/ResponseCoordinator.cpp
+++ b/examples/companion_radio/ResponseCoordinator.cpp
@@ -153,6 +153,21 @@ bool suppress(BotCoordinatorPending pending[], size_t pending_count, BotFingerpr
   return suppressed;
 }
 
+bool suppressByRequestToken(BotCoordinatorPending pending[], size_t pending_count, uint16_t request_token) {
+  if (!pending) return false;
+  bool suppressed = false;
+  for (size_t i = 0; i < pending_count; i++) {
+    if (!pending[i].active) continue;
+    if (pending[i].request_fingerprint.value == 0) continue;
+    uint16_t token = (uint16_t)(pending[i].request_fingerprint.value & 0xFFFFu);
+    if (token == request_token) {
+      pending[i].suppressed = true;
+      suppressed = true;
+    }
+  }
+  return suppressed;
+}
+
 bool cancel(BotCoordinatorPending pending[], size_t pending_count, BotFingerprint request_fingerprint) {
   if (!pending || request_fingerprint.value == 0) return false;
   for (size_t i = 0; i < pending_count; i++) {
diff --git a/examples/companion_radio/ResponseCoordinator.h b/examples/companion_radio/ResponseCoordinator.h
index f549b887..7e053b44 100644
--- a/examples/companion_radio/ResponseCoordinator.h
+++ b/examples/companion_radio/ResponseCoordinator.h
@@ -32,6 +32,7 @@ BotCoordinatorScheduleResult schedule(BotCoordinatorPending pending[], size_t pe
                                       uint8_t queue_depth, uint16_t base_delay_millis, uint16_t jitter_millis,
                                       uint16_t hop_step_millis, BotFingerprint* fingerprint, uint32_t* due_at_millis);
 bool suppress(BotCoordinatorPending pending[], size_t pending_count, BotFingerprint response_fingerprint);
+bool suppressByRequestToken(BotCoordinatorPending pending[], size_t pending_count, uint16_t request_token);
 bool cancel(BotCoordinatorPending pending[], size_t pending_count, BotFingerprint request_fingerprint);
 BotCoordinatorReady poll(BotCoordinatorPending pending[], size_t pending_count, uint32_t now_millis);
 void recordRecent(BotCoordinatorRecent recent[], size_t recent_count, BotFingerprint response_fingerprint,