When completed, the 30.08 km (18.69 mi) line will connect Bhayander with the Chhatrapati Shivaji Maharaj International Airport with 24 stations.

The line is served by six-car trains, manufactured by Bharat Earth Movers Limited, with a headway of 10 minutes.

[4] Over the course of two weeks in March–April 2017, Mumbai residents saved nearly 4,000 plants growing on dividers and along the Western Express Highway that had not been marked for replanting by metro authorities.

[5] In April 2017, the Ministry of Civil Aviation approved the transfer of 40 acres of land in Dahisar for the construction of the metro depot.

[8] In June 2017, the Maharashtra Government transferred three plots of land at Aarey Colony, measuring a total of 20,387 sqm (5.03 acres), to the MMRDA for a labour camp and a casting yard for Line 7, and a centralised operation centre for the metro system.

[12] In February 2017, the MMRDA announced that the DMRC was preparing a detailed project report (DPR) on a proposed 9 km (5.6 mi) extension of Line 7 from Dahisar to Bhayander, via Mira Road.

[14][15][16] In March 2017, the MMRDA stated that the DMRC was conducting a feasibility study to extend the line to Terminal 2 of the Chhatrapati Shivaji Maharaj International Airport.

[18][19][20] The alignment for the extension from Andheri to Chhatrapati Shivaji Maharaj International Terminus was approved by the State Cabinet on 12 April 2017.

Both lines were extended on 19 January 2023, providing circular service between Gundavali and Andheri West via Dahisar East.

[34] The bhoomipujan ceremony for Line 7 was performed by Prime Minister Narendra Modi during his visit to Mumbai on 11 October 2015.

In April 2016, the MMRDA awarded contracts to Simplex Infrastructure, J Kumar Infraprojects, and Nagarjuna Construction Company for the first, second and third packages respectively.

The single pier design was chosen to facilitate the construction of smaller stations and reduce the amount of land occupied on the Western Express Highway which could obstruct traffic flow.

[44] On 14 March 2017, the Mumbai High Court temporarily stayed all construction activities at Metro 7's casting yard in Bandra Reclamation.

The damage to the Mahanagar Gas pipeline resulted in temporary disruptions in the supply of CNG to Kandivli, Borivli, Dahisar, Mira Road and Bhayander.

[49] The BMC accused Nagarjuna Construction Company of illegally operating an unlicensed concrete ready mix plant at its casting yard in April 2017.

[51][52] The first U-girder, the concrete structure on which metro tracks are laid, was launched near Pathanwadi Junction in Malad on 2 May 2017.

During this period, multi-axle trailers transported U-girders weighing 170 tonne from the casting yard in Bandra to the location where it is to be erected.

The trailer had to move slowly to avoid causing imbalance to the heavy load which can result in toppling, and took roughly two hours to complete the journey.

Lifting the girder and attaching it to the pier caps was also a difficult process and was carried out at night time.

[56] By August 2017, about 600-700 metres of each package had been constructed, 63 piers and 22 girders had been erected, and barricades had been placed on 67% of the entire route.

[59] In January 2020, the MMRDA terminated the contract awarded to Simplex Infrastructure for the first package over delay in completing the work.

[65][66] The MMRDA began a dynamic test and trial run on the 20 km stretch between Dhanukarwadi and Aarey (including a portion of Line 2) on 19 June.

[67] The stretch between Dhanukarwadi and Aarey received provisional approval from the Research Designs and Standards Organisation (RDSO) in January 2022.

[70] The remaining section of Line 7 from Goregaon East to Gundavali received approval from the RDSO in October 2022.

[81] The Asian Development Bank (ADB) will provide 43-48% of the total project cost through a loan at an interest rate of 1.4%.

[93][88] Line 7 utilises the Alstom Urbalis 400 communications-based train control (CBTC) signalling system.

[96][97] MMRDA plans to install solar panels on the roofs of 13 stations on Line 7 to generate 2,000 kW of power.

[99][100][101] From 1 May 2023, a 25% discount on ticket fare was implemented for senior citizens (over 65 years), disabled persons, and students up to Class 12.