Repro: GMAIL_BATCH_MODIFY_MESSAGES fabricates modified_count (Composio bug)

repro-batch-modify-bug.ts

/**
 * Repro: GMAIL_BATCH_MODIFY_MESSAGES fabricates modified_count
 *
 * Gmail's batchModify returns 204 No Content — no count. Composio synthesizes
 * modified_count by echoing back len(messageIds), even for nonexistent IDs.
 *
 * Requires: COMPOSIO_API_KEY in env, Gmail OAuth (opens browser)
 * Run: bun run scripts/repro-batch-modify-bug.ts
 */

import { Composio } from '@composio/core'

const composio = new Composio({ apiKey: process.env.COMPOSIO_API_KEY! })
const userId = `repro-${Date.now()}`

async function mcpCall(mcp: { url: string; headers: Record<string, string> }, tool: string, args: Record<string, unknown>) {
  const res = await fetch(mcp.url, {
    method: 'POST',
    headers: { ...mcp.headers, 'Content-Type': 'application/json', Accept: 'application/json, text/event-stream' },
    body: JSON.stringify({ jsonrpc: '2.0', method: 'tools/call', params: { name: tool, arguments: args }, id: 1 }),
  })
  const text = await res.text()
  for (const line of text.split('\n')) {
    if (!line.startsWith('data: ')) continue
    const parsed = JSON.parse(line.slice(6))
    if (parsed?.result) return JSON.parse(parsed.result.content[0].text)
  }
}

// 1. Connect Gmail
const session = await composio.create(userId)
const auth = await session.authorize('gmail')
console.log(`Complete OAuth: ${auth.redirectUrl}`)
await Bun.spawn(['open', auth.redirectUrl]).exited
const conn = await auth.waitForConnection(120_000)
console.log(`Connected: ${conn.id}\n`)

const { mcp } = await composio.create(userId, { toolkits: ['gmail'] })

// 2. Get 2 real message IDs
const fetchResult = await mcpCall(mcp, 'COMPOSIO_MULTI_EXECUTE_TOOL', {
  tools: [{ tool_slug: 'GMAIL_FETCH_EMAILS', arguments: { query: 'in:inbox newer_than:7d', max_results: 2 } }],
})
const messages = fetchResult.data.results[0].response.data.messages
const realIds = messages.map((m: { messageId: string }) => m.messageId)
console.log(`Real IDs: ${realIds.join(', ')}`)

// 3. Batch modify with 2 real + 2 fake IDs
const fakeIds = ['1000000000000001', '1000000000000002']
const allIds = [...realIds, ...fakeIds]
console.log(`Sending batch modify with ${allIds.length} IDs (${realIds.length} real, ${fakeIds.length} fake)\n`)

const batchResult = await mcpCall(mcp, 'COMPOSIO_MULTI_EXECUTE_TOOL', {
  tools: [{ tool_slug: 'GMAIL_BATCH_MODIFY_MESSAGES', arguments: { messageIds: allIds, addLabelIds: ['STARRED'] } }],
})

console.log('Result:', JSON.stringify(batchResult.data.results[0].response.data, null, 2))
console.log(`\nExpected modified_count: ${realIds.length} (only real messages exist)`)
console.log(`Actual modified_count:   ${batchResult.data.results[0].response.data.modified_count}`)

// Cleanup
await mcpCall(mcp, 'COMPOSIO_MULTI_EXECUTE_TOOL', {
  tools: [{ tool_slug: 'GMAIL_BATCH_MODIFY_MESSAGES', arguments: { messageIds: realIds, removeLabelIds: ['STARRED'] } }],
})
await composio.connectedAccounts.delete(conn.id)