fix(mitm): Kiro binary EventStream crash + add models & TTS tool filtering

- server.js: isBinaryData() skips binary AWS EventStream bodies (fix JSON parse crash)
- kiro.js: isBinaryEventStream detection + migrate to pipeTransformedEventStream pipeline
- base.js: add pipeTransformedSSE / pipeTransformedEventStream helpers
- chatCore.js: filter tool messages + tools for TTS models via getModelType()
- providerModels.js: add getModelType()
- cliTools.js: add gpt-5-mini (Copilot), glm-5 & minimax-m2.5 (Kiro)

Co-authored-by: Cursor <cursoragent@cursor.com>

open-sse/config/providerModels.js

@@ -858,6 +858,13 @@ export function getModelTargetFormat(aliasOrId, modelId) {
   return found?.targetFormat || null;
 }
 
+export function getModelType(aliasOrId, modelId) {
+  const models = PROVIDER_MODELS[aliasOrId];
+  if (!models) return null;
+  const found = models.find(m => m.id === modelId);
+  return found?.type || null;
+}
+
 export function getModelUpstreamId(aliasOrId, modelId) {
   const models = PROVIDER_MODELS[aliasOrId];
   const found = models?.find(m => m.id === modelId);

open-sse/handlers/chatCore.js

@@ -5,7 +5,7 @@ import { COLORS } from "../utils/stream.js";
 import { createStreamController } from "../utils/streamHandler.js";
 import { refreshWithRetry } from "../services/tokenRefresh.js";
 import { createRequestLogger } from "../utils/requestLogger.js";
-import { getModelTargetFormat, getModelStrip, getModelUpstreamId, PROVIDER_ID_TO_ALIAS } from "../config/providerModels.js";
+import { getModelTargetFormat, getModelStrip, getModelUpstreamId, getModelType, PROVIDER_ID_TO_ALIAS } from "../config/providerModels.js";
 import { createErrorResult, parseUpstreamError, formatProviderError } from "../utils/error.js";
 import { HTTP_STATUS } from "../config/runtimeConfig.js";
 import { handleBypassRequest } from "../utils/bypassHandler.js";
@@ -115,6 +115,12 @@ export async function handleChatCore({ body, modelInfo, credentials, log, onCred
   // Covers both passthrough (source shape) and translated (target shape) flows
   const finalFormat = passthrough ? sourceFormat : targetFormat;
 
+  // TTS models don't support tool messages/function calling
+  if (getModelType(alias, model) === "tts" && translatedBody.messages) {
+    translatedBody.messages = translatedBody.messages.filter(msg => msg.role !== "tool");
+    delete translatedBody.tools;
+  }
+
   // RTK: compress tool_result content
   const rtkStats = compressMessages(translatedBody, rtkEnabled);
   const rtkLine = formatRtkLog(rtkStats);

src/mitm/handlers/base.js

@@ -65,4 +65,162 @@ async function pipeSSE(routerRes, res, dumper) {
   }
 }
 
-module.exports = { fetchRouter, pipeSSE };
+/**
+ * Pipe SSE stream from router, transforming each chunk through a user function.
+ * Reads SSE data: lines, parses JSON, calls transformFn(parsed, state),
+ * and writes returned SSE strings to the client response.
+ *
+ * @param {Response} routerRes - Fetch Response from 9Router
+ * @param {http.ServerResponse} res - Client response
+ * @param {Function} transformFn - (parsedChunk, state) => string|string[]|null
+ * @param {object} state - Mutable state object shared across chunks and flush
+ */
+async function pipeTransformedSSE(routerRes, res, transformFn, state) {
+  const ct = routerRes.headers.get("content-type") || "application/json";
+  const resHeaders = { "Content-Type": ct, "Cache-Control": "no-cache", "Connection": "keep-alive" };
+  if (ct.includes("text/event-stream")) resHeaders["X-Accel-Buffering"] = "no";
+  res.writeHead(200, resHeaders);
+
+  if (!routerRes.body) {
+    res.end(await routerRes.text().catch(() => ""));
+    return;
+  }
+
+  const reader = routerRes.body.getReader();
+  const decoder = new TextDecoder("utf-8", { fatal: false });
+  let buffer = "";
+
+  while (true) {
+    const { done, value } = await reader.read();
+    if (done) break;
+
+    buffer += decoder.decode(value, { stream: true });
+    const lines = buffer.split("\n");
+    buffer = lines.pop() || "";
+
+    for (const line of lines) {
+      const trimmed = line.trim();
+      if (!trimmed || !trimmed.startsWith("data:")) continue;
+
+      const data = trimmed.slice(5).trim();
+      if (data === "[DONE]") continue;
+
+      if (process.env.DEBUG_MITM) {
+        log(`[SSE in] ${data.slice(0, 200)}`);
+      }
+
+      try {
+        const parsed = JSON.parse(data);
+        const result = transformFn(parsed, state);
+        if (result != null) {
+          const outputs = Array.isArray(result) ? result : [result];
+          for (const output of outputs) {
+            if (process.env.DEBUG_MITM) {
+              const len = output.length || output.byteLength || 0;
+              log(`[write binary frame] (${len}B) first 20B: ${Array.from(output.slice(0, 20)).join(',')}`);
+            }
+            res.write(Buffer.from(output));
+          }
+        }
+      } catch {
+        // Skip unparseable lines
+      }
+    }
+  }
+
+  // Flush: pass null to signal stream end
+  try {
+    const flushed = transformFn(null, state);
+    if (flushed != null) {
+      const outputs = Array.isArray(flushed) ? flushed : [flushed];
+      for (const output of outputs) {
+        res.write(output);
+      }
+    }
+  } catch { /* ignore flush errors */ }
+
+  res.end();
+}
+
+/**
+ * Pipe SSE stream from router, transforming each chunk through a user function,
+ * and writing binary EventStream frames to the client.
+ *
+ * Reads SSE data: lines, parses JSON, calls transformFn(parsed, state),
+ * and writes returned Uint8Array frames to the client response.
+ *
+ * @param {Response} routerRes - Fetch Response from 9Router
+ * @param {http.ServerResponse} res - Client response
+ * @param {Function} transformFn - (parsedChunk, state) => Uint8Array|Uint8Array[]|null
+ * @param {object} state - Mutable state object shared across chunks and flush
+ */
+async function pipeTransformedEventStream(routerRes, res, transformFn, state) {
+  const resHeaders = {
+    "Content-Type": "application/vnd.amazon.eventstream",
+    "Cache-Control": "no-cache",
+    "Connection": "keep-alive"
+  };
+  res.writeHead(200, resHeaders);
+
+  if (!routerRes.body) {
+    res.end(await routerRes.text().catch(() => ""));
+    return;
+  }
+
+  const reader = routerRes.body.getReader();
+  const decoder = new TextDecoder("utf-8", { fatal: false });
+  let buffer = "";
+
+  while (true) {
+    const { done, value } = await reader.read();
+    if (done) break;
+
+    buffer += decoder.decode(value, { stream: true });
+    const lines = buffer.split("\n");
+    buffer = lines.pop() || "";
+
+    for (const line of lines) {
+      const trimmed = line.trim();
+      if (!trimmed || !trimmed.startsWith("data:")) continue;
+
+      const data = trimmed.slice(5).trim();
+      if (data === "[DONE]") continue;
+
+      if (process.env.DEBUG_MITM) {
+        log(`[SSE in] ${data.slice(0, 200)}`);
+      }
+
+      try {
+        const parsed = JSON.parse(data);
+        const result = transformFn(parsed, state);
+        if (result != null) {
+          const outputs = Array.isArray(result) ? result : [result];
+          for (const output of outputs) {
+            if (process.env.DEBUG_MITM) {
+              const len = output.length || output.byteLength || 0;
+              log(`[write binary frame] (${len}B) first 20B: ${Array.from(output.slice(0, 20)).join(',')}`);
+            }
+            res.write(Buffer.from(output));
+          }
+        }
+      } catch {
+        // Skip unparseable lines
+      }
+    }
+  }
+
+  // Flush: pass null to signal stream end
+  try {
+    const flushed = transformFn(null, state);
+    if (flushed != null) {
+      const outputs = Array.isArray(flushed) ? flushed : [flushed];
+      for (const output of outputs) {
+        res.write(output);
+      }
+    }
+  } catch { /* ignore flush errors */ }
+
+  res.end();
+}
+
+module.exports = { fetchRouter, pipeSSE, pipeTransformedSSE, pipeTransformedEventStream };

src/mitm/handlers/kiro.js

@@ -1,6 +1,6 @@
 const { err } = require("../logger");
 const { IS_DEV } = require("../config");
-const { fetchRouter } = require("./base");
+const { fetchRouter, pipeTransformedEventStream } = require("./base");
 const fs = require("fs");
 const path = require("path");
 
@@ -32,6 +32,76 @@ function crc32(buf) {
   return (crc ^ 0xffffffff) >>> 0;
 }
 
+/**
+ * Initialize state for the Kiro response translator
+ */
+function initKiroState(modelId) {
+  return {
+    modelId: modelId || null,       // Model name from first chunk
+    toolCallInit: {},               // { [index]: { id, name } } — tracks seen tools
+    hasToolCalls: false,           // Whether this response uses tool calls
+    finishSent: false,             // Whether termination has been emitted
+    usage: null,                   // Accumulated usage from usage-only chunks
+    inThink: false,                // Whether inside a <thinking> block
+    thinkBuf: ""                   // Buffer for partial thinking content
+  };
+}
+
+/**
+ * Extract thinking blocks from text content.
+ * Handles both <thinking>...</thinking> and <think>...</think> tags,
+ * including partial tags split across SSE chunks.
+ */
+function extractThinking(text, state) {
+  if (!text) return { thinking: null, text: null };
+
+  let working = text;
+
+  // Prepend buffered partial thinking from previous chunk
+  if (state.inThink && state.thinkBuf) {
+    working = state.thinkBuf + working;
+    state.thinkBuf = "";
+    state.inThink = false;
+  }
+
+  // Match <thinking> or <think> opening tags
+  const startRe = /<thinking>|<think>/i;
+  const startMatch = working.match(startRe);
+
+  if (!startMatch) {
+    return { thinking: null, text: working };
+  }
+
+  const tag = startMatch[0].toLowerCase();
+  const closeTag = tag === "<think>" ? "</think>" : "</thinking>";
+  const startIdx = startMatch.index;
+  const endIdx = working.indexOf(closeTag, startIdx + tag.length);
+
+  if (endIdx === -1) {
+    // Opening tag without closing — buffer for next chunk
+    state.inThink = true;
+    state.thinkBuf = working.slice(startIdx);
+    const before = working.slice(0, startIdx).trim();
+    return { thinking: null, text: before || null };
+  }
+
+  // Complete block found
+  const thinking = working.slice(startIdx + tag.length, endIdx);
+  const before = working.slice(0, startIdx).trim();
+  const after = working.slice(endIdx + closeTag.length).trim();
+  const rest = [before, after].filter(Boolean).join("");
+
+  // Recursively process for more blocks
+  const recurse = rest
+    ? extractThinking(rest, { inThink: false, thinkBuf: "" })
+    : { thinking: null, text: null };
+
+  return {
+    thinking: thinking || null,
+    text: recurse.text || null
+  };
+}
+
 // ─── AWS EventStream frame builder ────────────────────────────────────────────
 /**
  * Encode a single string header into the AWS EventStream binary format.
@@ -233,132 +303,173 @@ function extractTools(body) {
 }
 
 // ─── OpenAI SSE → EventStream binary conversion ───────────────────────────────
+
 /**
- * Read 9router's OpenAI SSE response and re-encode it as AWS EventStream binary
+ * Convert an OpenAI SSE chunk to AWS EventStream binary frame(s)
- * frames that Kiro's Smithy SDK expects.
+ * This replaces pipeOpenAIasEventStream and works with pipeTransformedEventStream
  *
- * OpenAI SSE format:  data: { choices:[{ delta:{ content:"..." } }] }\n\n
+ * @param {object|null} chunk - Parsed OpenAI chat.completion.chunk, or null for flush
- * EventStream events emitted:
+ * @param {object} state - Mutable state object
- *   assistantResponseEvent  { content: "..." }   — one per SSE chunk with text
+ * @returns {Uint8Array|Uint8Array[]|null} Binary EventStream frame(s) or null to skip
- *   toolUseEvent            { toolUseId, name, input }   — for tool calls
- *   messageStopEvent        {}                   — on finish
  */
-async function pipeOpenAIasEventStream(routerRes, res) {
+function convertOpenAIToKiro(chunk, state) {
-  if (!routerRes.body) {
+  // Flush: ensure clean stream termination
-    res.end(buildEventStreamFrame("messageStopEvent", {}));
+  if (!chunk) {
-    return;
+    if (state.finishSent) return null;
+    // Flush any remaining buffered thinking
+    if (state.inThink && state.thinkBuf) {
+      state.inThink = false;
+      const thinking = state.thinkBuf;
+      state.thinkBuf = "";
+      return buildEventStreamFrame("reasoningContentEvent", {
+        content: thinking,
+        modelId: state.modelId || "kiro-unknown"
+      });
+    }
+    return buildEventStreamFrame("messageStopEvent", {});
   }
 
-  const reader = routerRes.body.getReader();
+  const frames = [];
-  const decoder = new TextDecoder();
+  const choice = chunk.choices?.[0];
-  let sseBuffer = "";
+  const delta = choice?.delta || {};
-  let stopSent = false;
 
-  // Accumulated tool-call state keyed by index
+  // Capture modelId from first chunk (real API includes it in every content frame)
-  const toolCallAccum = {};
+  if (!state.modelId && chunk.model) {
+    state.modelId = chunk.model;
+  }
+  const modelId = state.modelId || "unknown";
 
-  const sendStop = () => {
+  // Handle usage (may arrive standalone or with other chunks)
-    if (!stopSent) {
+  if (chunk.usage) {
-      stopSent = true;
+    state.usage = chunk.usage;
-      res.write(buildEventStreamFrame("messageStopEvent", {}));
+  }
-    }
-  };
 
-  try {
+  // Handle tool calls — stream incrementally, matching real API format
-    while (true) {
+  if (delta.tool_calls) {
-      const { done, value } = await reader.read();
+    state.hasToolCalls = true;
-      if (done) break;
+    for (const tc of delta.tool_calls) {
+      const idx = tc.index ?? 0;
 
-      sseBuffer += decoder.decode(value, { stream: true });
+      if (tc.id && tc.function?.name && !state.toolCallInit[idx]) {
+        // First appearance: emit frame with name + id, no input
+        state.toolCallInit[idx] = { id: tc.id, name: tc.function.name };
+        dbg(`toolUseEvent init: ${tc.function.name} (${tc.id})`);
+        frames.push(buildEventStreamFrame("toolUseEvent", {
+          name: tc.function.name,
+          toolUseId: tc.id
+        }));
+      }
 
-      // Split on newlines; keep the last (possibly incomplete) line in the buffer
+      // Emit incremental input fragment
-      const lines = sseBuffer.split("\n");
+      if (tc.function?.arguments) {
-      sseBuffer = lines.pop() ?? "";
+        const init = state.toolCallInit[idx];
-
+        dbg(`toolUseEvent fragment: ${tc.function.arguments.slice(0, 100)}`);
-      for (const line of lines) {
+        frames.push(buildEventStreamFrame("toolUseEvent", {
-        const trimmed = line.trim();
+          input: tc.function.arguments,
-        if (!trimmed.startsWith("data:")) continue;
+          name: init?.name || tc.function?.name || "",
-
+          toolUseId: init?.id || tc.id || ""
-        const raw = trimmed.slice(5).trim();
+        }));
-        if (raw === "[DONE]") {
-          sendStop();
-          continue;
-        }
-
-        let chunk;
-        try { chunk = JSON.parse(raw); } catch { continue; }
-
-        const delta = chunk?.choices?.[0]?.delta;
-        if (!delta) continue;
-
-        // ── Text content ───────────────────────────────────────────────────────
-        if (delta.content) {
-          res.write(buildEventStreamFrame("assistantResponseEvent", { content: delta.content }));
-        }
-
-        // ── Tool calls (streamed in pieces by OpenAI SSE) ──────────────────────
-        if (delta.tool_calls) {
-          dbg(`TOOL_CALLS delta: ${JSON.stringify(delta.tool_calls).slice(0, 300)}`);
-          for (const tc of delta.tool_calls) {
-            const idx = tc.index ?? 0;
-            if (!toolCallAccum[idx]) {
-              toolCallAccum[idx] = { id: tc.id ?? "", name: "", args: "" };
-            }
-            const acc = toolCallAccum[idx];
-            if (tc.id) acc.id = tc.id;
-            if (tc.function?.name) acc.name += tc.function.name;
-            // safeArgsString prevents `"" + object` → "[object Object]" corruption
-            // when 9router's Anthropic→OpenAI conversion passes a pre-parsed object
-            const argType = typeof tc.function?.arguments;
-            if (tc.function?.arguments != null) {
-              acc.args += safeArgsString(tc.function.arguments);
-            }
-            dbg(`  tc[${idx}] argType=${argType} id=${acc.id} name=${acc.name} args_so_far=${acc.args.slice(0, 100)}`);
-          }
-        }
-
-        // ── Finish ─────────────────────────────────────────────────────────────
-        const finish = chunk?.choices?.[0]?.finish_reason;
-        if (finish) {
-          dbg(`FINISH finish_reason=${finish} toolCallKeys=${JSON.stringify(Object.keys(toolCallAccum))}`);
-          // Flush accumulated tool calls before stop
-          if (finish === "tool_calls") {
-            for (const acc of Object.values(toolCallAccum)) {
-              // IMPORTANT: Kiro's internal tool dispatcher expects `input` to be a JSON string
-              // (not a parsed object). The real CodeWhisperer server sends:
-              //   { toolUseId, name, input: "{\"key\":\"value\"}" }  ← input is a string
-              // Kiro then JSON.parses that string to get the tool arguments.
-              // If we send input as a parsed object, Kiro does String(obj) → "[object Object]".
-              const inputStr = acc.args || "{}";
-              dbg(`  toolUseEvent: id=${acc.id} name=${acc.name} inputStr=${inputStr.slice(0, 200)}`);
-              res.write(buildEventStreamFrame("toolUseEvent", {
-                toolUseId: acc.id,
-                name: acc.name,
-                input: inputStr,  // Must be a JSON STRING, not a parsed object
-              }));
-            }
-          }
-          sendStop();
-        }
       }
     }
-  } finally {
-    sendStop();
-    res.end();
   }
+
+  // Handle explicit reasoning_content (type-specific thinking channel)
+  if (delta.reasoning_content) {
+    frames.push(buildEventStreamFrame("reasoningContentEvent", {
+      content: delta.reasoning_content,
+      modelId
+    }));
+  }
+
+  // Handle text content — extract thinking blocks, emit rest as assistantResponseEvent
+  if (delta.content) {
+    const { thinking, text } = extractThinking(delta.content, state);
+
+    if (thinking) {
+      frames.push(buildEventStreamFrame("reasoningContentEvent", {
+        content: thinking,
+        modelId
+      }));
+    }
+
+    if (text) {
+      frames.push(buildEventStreamFrame("assistantResponseEvent", {
+        content: text,
+        modelId
+      }));
+    }
+  }
+
+  // Handle finish_reason
+  if (choice?.finish_reason) {
+    const finishFrames = emitFinish(state);
+    if (finishFrames) {
+      frames.push(...(Array.isArray(finishFrames) ? finishFrames : [finishFrames]));
+    }
+  }
+
+  if (frames.length === 0) return null;
+  return frames.length === 1 ? frames[0] : frames;
+}
+
+/**
+ * Emit termination frames. For tool-call responses, emits stop:true per tool.
+ * For text-only responses, emits messageStopEvent.
+ */
+function emitFinish(state) {
+  const frames = [];
+
+  if (state.hasToolCalls) {
+    // Tool-call response: emit stop:true for each tool
+    for (const idx of Object.keys(state.toolCallInit).sort()) {
+      const tc = state.toolCallInit[idx];
+      frames.push(buildEventStreamFrame("toolUseEvent", {
+        name: tc.name,
+        stop: true,
+        toolUseId: tc.id
+      }));
+    }
+  } else {
+    // Text-only response: emit messageStopEvent
+    frames.push(buildEventStreamFrame("messageStopEvent", {}));
+  }
+  state.finishSent = true;
+
+  // Emit usage if available
+  if (state.usage) {
+    frames.push(buildEventStreamFrame("usageEvent", {
+      inputTokens: state.usage.prompt_tokens || 0,
+      outputTokens: state.usage.completion_tokens || 0
+    }));
+  }
+
+  state.toolCallInit = {};
+  return frames.length > 0 ? frames : null;
 }
 
 // ─── MITM intercept entry point ───────────────────────────────────────────────
 /**
- * Intercept Kiro IDE CodeWhisperer request:
+ * Intercept Kiro IDE CodeWhisperer request and convert to EventStream response:
- *   1. Parse CodeWhisperer binary/JSON body
+ *   1. Parse CodeWhisperer JSON body (reject binary EventStream formats)
- *   2. Convert to OpenAI messages[] format
+ *   2. Convert CodeWhisperer format to OpenAI messages[] format
  *   3. Forward to 9router /v1/chat/completions (OpenAI SSE)
  *   4. Convert OpenAI SSE response → AWS EventStream binary frames
- *   5. Stream binary frames back to Kiro
+ *   5. Stream EventStream frames back to Kiro IDE
+ * 
+ * @param {http.IncomingMessage} req - HTTP request from Kiro IDE
+ * @param {http.ServerResponse} res - HTTP response to Kiro IDE  
+ * @param {Buffer} bodyBuffer - Request body buffer
+ * @param {string} mappedModel - Model name after MITM alias mapping
  */
 async function intercept(req, res, bodyBuffer, mappedModel) {
   try {
+    // Detect and handle binary data (e.g., continuation requests with EventStream frames)
+    if (isBinaryEventStream(bodyBuffer)) {
+      // Binary EventStream requests are typically continuation/streaming frames
+      // that don't contain model info - pass them through directly to avoid JSON.parse crash
+      throw new Error(`Binary EventStream format detected (${bodyBuffer.length}B) - request should use passthrough instead of intercept`);
+    }
+    
     const body = JSON.parse(bodyBuffer.toString());
 
     // 1 + 2: CodeWhisperer → OpenAI messages + tools
@@ -380,22 +491,36 @@ async function intercept(req, res, bodyBuffer, mappedModel) {
     // 3: Forward to 9router
     const routerRes = await fetchRouter(openaiBody, "/v1/chat/completions", req.headers);
 
-    // 4 + 5: Re-encode response as AWS EventStream binary
+    // 4 + 5: Re-encode response as AWS EventStream binary using standard pipeline
-    res.writeHead(routerRes.status, {
+    const state = initKiroState(mappedModel);
-      "Content-Type": "application/vnd.amazon.eventstream",
-      "x-amzn-requestid": `mitm-${Date.now()}`,
-      "x-amz-id-2": "mitm",
-      "Transfer-Encoding": "chunked",
-    });
 
-    await pipeOpenAIasEventStream(routerRes, res);
+    await pipeTransformedEventStream(routerRes, res, convertOpenAIToKiro, state);
   } catch (error) {
-    err(`[Kiro] ${error.message}`);
+    err(`[Kiro MITM] Request processing failed: ${error.message}`);
     if (!res.headersSent) {
       res.writeHead(500, { "Content-Type": "application/json" });
     }
-    res.end(JSON.stringify({ error: { message: error.message, type: "mitm_error" } }));
+    res.end(JSON.stringify({ 
+      error: { 
+        message: error.message, 
+        type: "mitm_error",
+        handler: "kiro"
+      } 
+    }));
   }
 }
 
+// Detect AWS EventStream binary format
+function isBinaryEventStream(buffer) {
+  if (!buffer || buffer.length < 12) return false;
+  // AWS EventStream signature: 
+  // - First 4 bytes: total frame length (big-endian)
+  // - Bytes 4-8: headers length (big-endian)
+  // - Typical frame length: 100-10000 bytes
+  const totalLen = buffer.readUInt32BE(0);
+  const headersLen = buffer.readUInt32BE(4);
+  // Sanity checks: frame length should be reasonable and headers should fit
+  return totalLen > 12 && totalLen < 1000000 && headersLen < totalLen - 12;
+}
+
 module.exports = { intercept };

src/mitm/server.js

@@ -95,6 +95,10 @@ function collectBodyRaw(req) {
 function extractModel(url, body) {
   const urlMatch = url.match(/\/models\/([^/:]+)/);
   if (urlMatch) return urlMatch[1];
+  
+  // Skip parsing if body is binary (AWS EventStream, Protocol Buffers, etc.)
+  if (isBinaryData(body)) return null;
+  
   try {
     const parsed = JSON.parse(body.toString());
     if (parsed.conversationState) {
@@ -104,6 +108,25 @@ function extractModel(url, body) {
   } catch { return null; }
 }
 
+// Detect binary data vs JSON text
+function isBinaryData(buffer) {
+  if (!buffer || buffer.length === 0) return false;
+  // AWS EventStream signature: first 4 bytes = frame length (big-endian uint32)
+  // Check for non-printable chars in first 100 bytes (common in binary protocols)
+  const sample = buffer.slice(0, Math.min(100, buffer.length));
+  let nonPrintable = 0;
+  for (let i = 0; i < sample.length; i++) {
+    const byte = sample[i];
+    // Count non-ASCII printable chars (excluding whitespace)
+    if (byte < 0x20 && byte !== 0x09 && byte !== 0x0A && byte !== 0x0D) {
+      nonPrintable++;
+    }
+    if (byte > 0x7E) nonPrintable++;
+  }
+  // If >30% non-printable, treat as binary
+  return (nonPrintable / sample.length) > 0.3;
+}
+
 function getMappedModel(tool, model) {
   if (!model) return null;
   try {

src/shared/constants/cliTools.js

@@ -38,6 +38,7 @@ export const MITM_TOOLS = {
     defaultModels: [
       { id: "gpt-4o", name: "GPT-4o", alias: "gpt-4o" },
       { id: "gpt-4.1", name: "GPT-4.1", alias: "gpt-4.1" },
+      { id: "gpt-5-mini", name: "GPT-5 Mini", alias: "gpt-5-mini" },
       { id: "claude-haiku-4.5", name: "Claude Haiku 4.5", alias: "claude-haiku-4.5" },
     ],
   },
@@ -59,7 +60,9 @@ export const MITM_TOOLS = {
       { id: "claude-sonnet-4", name: "Claude Sonnet 4", alias: "claude-sonnet-4" },
       { id: "claude-haiku-4.5", name: "Claude Haiku 4.5", alias: "claude-haiku-4.5" },
       { id: "deepseek-3.2", name: "DeepSeek 3.2", alias: "deepseek-3.2" },
+      { id: "minimax-m2.5", name: "MiniMax M2.5", alias: "minimax-m2.5" },
       { id: "minimax-m2.1", name: "MiniMax M2.1", alias: "minimax-m2.1" },
+      { id: "glm-5", name: "GLM 5", alias: "glm-5" },
       { id: "simple-task", name: "Qwen3 Coder Next", alias: "simple-task" },
     ],
   },