> ## Documentation Index
> Fetch the complete documentation index at: https://docs.istravex.com/llms.txt
> Use this file to discover all available pages before exploring further.

# The corpus

> What the corpus holds, where each piece comes from, and why you can trust it.

The corpus is the heart of Istravex. Everything else, from the SDK runners and replay to the pilot and the linter's calibration, exists to run code against it.

It's a directory in the repository:

```
corpus/
├── fixtures/<id>/            manifest.json + one base64 file per XDR value
├── ledgers/<network>/<seq>.xdr.zst   canonical LedgerCloseMeta, zstd
├── ledgers/index.json        sha256 and source of every stored ledger
├── manifest.schema.json      JSON Schema 2020-12 for manifests
├── coverage.json             the CAP audit
└── results/                  output of every kit stage
```

## What's in it today

| Fixture | CAP | Network | Ledger | Protocol | Transaction |
| - | - | - | - | - | - |
| `cap15-fee-bump-pubnet-0001` | CAP-0015 | pubnet | 65,474,309 | 29 | [ebfeab…3239fd](https://stellar.expert/explorer/public/tx/ebfeab1b8fedae07fb94ade40d0dad8ebda6781dbfb3c182996f13aba33239fd) |
| `cap27-muxed-payment-pubnet-0001` | CAP-0027 | pubnet | 65,474,279 | 29 | [fff233…c21395](https://stellar.expert/explorer/public/tx/fff2333a20af37c71d0bbe8360dd0476a81e41d2be63eb114a0b7e8e68c21395) |
| `cap40-signed-payload-signer-local-0001` | CAP-0040 | local | 9 | 30 | generated |
| `cap40-signed-payload-signer-testnet-0001` | CAP-0040 | testnet | 5,727,196 | 30 | [70b154…5157e1](https://stellar.expert/explorer/testnet/tx/70b1541948003725da367db63b7f4778f19ce96b3aea237c93f5eb24da5157e1) |
| `cap73-sac-trust-local-0001` | CAP-0073 | local | 13 | 30 | generated |
| `cap73-sac-trust-testnet-0001` | CAP-0073 | testnet | 5,727,199 | 30 | [ca0d15…f38b64](https://stellar.expert/explorer/testnet/tx/ca0d157350ba4c10b24f4466d25d003797659bfa2a369fe65a72da86c0f38b64) |

That's six fixtures for four CAPs. Two of them are the same scenario on two networks: CAP-0040 and CAP-0073 each exist as a testnet capture and as a fixture generated on a pinned stellar-core. That's deliberate. The testnet copy proves the pattern exists on a real network; the generated copy can be rebuilt by anyone, at any time, without depending on testnet (which resets).

## Three ways in

| How | Script | Used for |
| - | - | - |
| **Captured from mainnet** | `kit/capture/mainnet.mjs` | Patterns that already happen in the wild. Pinned by transaction hash, so re-running reproduces the same bytes. |
| **Created on testnet** | `kit/capture/testnet.mjs` | Patterns that are rare on mainnet but can be produced on demand. |
| **Generated on stellar-core** | `kit/capture/generate.mjs` | The same scenarios on a standalone network, fully reproducible, no external dependencies. |

Each has its own page: [Capturing](https://docs.istravex.com/corpus/capturing.md) covers the first two, [Generating](https://docs.istravex.com/corpus/generating.md) the third.

## Why you can trust it

A fixture is only as good as the claim that it's real. Three things back that claim:

1. **Canonical ledgers.** Every fixture's full ledger is stored, from the most authoritative source we could get (SDF's public data lake for mainnet), and its sha256 is recorded.
2. **Byte equality.** The [provenance verifier](https://docs.istravex.com/corpus/provenance.md) requires every XDR value in every fixture to be byte-identical to the ledger's copy. 62 checks, all passing, on every CI run.
3. **Independent expectations.** What a fixture says correct software should produce comes from Horizon or from the transaction as constructed, never from the SDKs being tested.

On top of the corpus, the SDKs are also checked against [stellar-core's own golden ledgers](https://docs.istravex.com/corpus/goldens.md): 15,306 `LedgerCloseMeta` frames from core's test suite.

## What it doesn't cover yet

Four CAPs is a start, not a finish. Of the 40 live CAPs that change XDR, 37 have no fixture yet. The [CAP coverage](https://docs.istravex.com/corpus/cap-coverage.md) page lists every one, and [Contributing a fixture](https://docs.istravex.com/corpus/contributing.md) explains how to close a gap.


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