Method discoverServerToolsImpl

apps/sim/lib/mcp/service.ts:629–714

(
    userId: string,
    serverId: string,
    workspaceId: string,
    forceRefresh: boolean
  )

  }

  private async discoverServerToolsImpl(
    userId: string,
    serverId: string,
    workspaceId: string,
    forceRefresh: boolean
  ): Promise<McpTool[]> {
    const requestId = generateRequestId()
    const maxRetries = 2

    if (!forceRefresh) {
      try {
        const cached = await this.cacheAdapter.get(serverCacheKey(workspaceId, serverId))
        if (cached) {
          logger.debug(`[${requestId}] Cache hit for server ${serverId}`)
          return cached.tools
        }
      } catch (error) {
        logger.warn(`[${requestId}] Cache read failed for server ${serverId}:`, error)
      }
      if (await this.isServerUnhealthy(workspaceId, serverId)) {
        logger.info(`[${requestId}] Skipping recently-failed server ${serverId} (negative-cache)`)
        throw new McpConnectionError(
          'Server recently failed and is in cooldown — try again shortly.',
          serverId
        )
      }
    }

    for (let attempt = 0; attempt < maxRetries; attempt++) {
      try {
        logger.info(
          `[${requestId}] Discovering tools from server ${serverId} for user ${userId}${attempt > 0 ? ` (attempt ${attempt + 1})` : ''}`
        )

        const config = await this.getServerConfig(serverId, workspaceId)
        if (!config) {
          throw new Error(`Server ${serverId} not found or not accessible`)
        }

        const { config: resolvedConfig, resolvedIP } = await this.resolveConfigEnvVars(
          config,
          userId,
          workspaceId
        )
        const client = await this.createClient(resolvedConfig, resolvedIP, userId)

        try {
          const tools = await client.listTools()
          logger.info(`[${requestId}] Discovered ${tools.length} tools from server ${config.name}`)
          await Promise.allSettled([
            this.cacheAdapter
              .set(serverCacheKey(workspaceId, serverId), tools, this.cacheTimeout)
              .catch((err) =>
                logger.warn(`[${requestId}] Cache write failed for ${config.name}:`, err)
              ),
            this.clearServerFailure(workspaceId, serverId),
            this.updateServerStatus(serverId, workspaceId, true, undefined, tools.length),
          ])