There are four ship codex entries that can be obtained on Coruscant. Each is restricted to one of the Republic classes. These codex entries are not required for any achievements.
The Jedi Consular's Corellian Defender-class Light Corvette codex entry location obtained from a conversation.
Codex type: Ships
Codex location: Coruscant: Senate Plaza: Senate Tower
Codex coordinates: -1258, -4591
Faction: Republic
Class: Jedi Consular
Associated Achievement: None
Special Requirements: You must progress the mission 'Ancient Secrets' to gain access to this codex entry
The Jedi Knight's Corellian Defender-class Light Corvette codex entry location obtained from a conversation.
Codex type: Ships
Codex location: Coruscant: Senate Plaza: Senate Tower
Codex coordinates: -1308, -4703
Faction: Republic
Class: Jedi Knight
Associated Achievement: None
Special Requirements: You must progress the mission 'Race to the Ruins' to gain access to this codex entry
The Corellian XS Stock Freighter codex entry location obtained from a conversation.
Codex type: Ships
Codex location: Coruscant: Coruscant Spaceport: Docking Bay 87
Codex coordinates: -944, -3676
Faction: Republic
Class: Smuggler
Associated Achievement: None
Special Requirements: You must progress the mission 'Race the Devil' to gain access to this codex entry
The Rendili Hyperworks BT-7 Thunderclap codex entry location obtained from a conversation.
Codex type: Ships
Codex location: Coruscant: Senate Plaza: Senate Tower
Codex coordinates: -1283, -4858
Faction: Republic
Class: Trooper
Associated Achievement: None
Special Requirements: You must progress the mission 'Assault on the Works' to gain access to this codex entry