CIP-118 - Nested Transactions

This is an umbrella ticket that lists all of the milestones for [Nested Transactions - CIP-118](https://github.com/cardano-foundation/CIPs/pull/862)

# Nested Transactions

## MS13.1: Preparation work

### Description

* [x] - Finalize the proposed CIP-0118 and have it accepted: cardano-foundation/CIPs#862
* [x] - Tackle tech debt preventing us from starting work on Nested Transactions:
* #5069
* #5068
* #4999
* #4873
* #4694
* #4613
* [x] - Define new blank Ledger era:
* #4955
* #5043

### Deadline

Q2 2025 - 30 Jun 25

### Acceptance

* [x] - CIP-0118 is merged: cardano-foundation/CIPs#862
* [x] - Necessary tech debt is resolved.
* #5005
* #5089 and #5100
* #5083
* #4966
* #5128
* [x] - New Dijkstra era is defined:
* #5030
* #5104

## MS13.2: Transaction definition

* [x] - Implement Transaction type and serialization:
* #4963
* #5000
* #5045
* #5121
* #5046 - Required a CIP: https://github.com/cardano-foundation/CIPs/pull/1084
* #5355
* #5356
* #5381
* #5405
* [x] - Define new Plutus Ledger version:
* #5105
* [x] - Coordinate with the Formal Methods team on formal specification implementation in Agda of the Ledger rules

### Deadline

Q3 2025 - 30 Sep 24

### Acceptance

* [x] - Transaction type is fully defined according to the CIP, serialization and CDDL spec are implemented:
* #5137
* #5097
* #5156
* #5332
* #5334
* #5430
* #5413
* #5457
* [x] - PlutusV4 is defined:
* #5111
* #5236
* #5275
* #5273
* [x] - New ledger era is integrated all the way into cardano-node: https://github.com/IntersectMBO/cardano-node/pull/6338

## MS13.3: Ledger rules

* [ ] - Work on the Ledger rules:
* #5401
* #5481
* #5489
* #5500

### Deadline

Q4 2025 - 31 Dec 25

### Acceptance

* [ ] - Most of the ledger rules functionality is defined with unit tests and property tests:
* #5490
* #5491
* #5506
* #5531
* #5534
* #5542
* #5526
* #5557
* #5544
* #5608
* #5614
* #5627
* #5676
* #5668
* #5692
* #5770
* #5737
* #5751
* [ ] - Specification in Agda is mostly complete.

## MS13.4: Plutus Context

* [ ] - Work with the Plutus team on defining Plutus Context for the transaction:
* #5633
* [ ] - Start work on conformance tests for Dijkstra era

### Deadline

Q1 2026 - 31 Mar 26

### Acceptance

* [ ] - PlutusV4 context is fully defined and it is possible to execute Plutus scripts that are aware of Nested Transactions:
* #5635
* #5636
* #5645
* #5754
* #5635
* #5636
* https://github.com/IntersectMBO/cardano-ledger/issues/5474
* https://github.com/IntersectMBO/cardano-ledger/issues/5403
* https://github.com/IntersectMBO/plutus/issues/7342
* https://github.com/IntersectMBO/cardano-ledger/issues/5925
* https://github.com/IntersectMBO/cardano-ledger/issues/5562
*
* [ ] - Ability to execute PlutusV4 script on a testnet.

## MS13.5: Testing and Conformance

* [ ] - Work on conformance tests, PlutusV4 tests and extend existing tests with more property tests.

### Deadline

Q2 2026 - 30 Jun 26

### Acceptance

* [ ] - Conformance test suite is capable of testing against the Agda specification.
* [ ] - Complete implementation, testing and integration.
* [ ] - `cardano-node` release that is fully capable of handling Nested Transactions in the new Dijkstra era