# SBOM Nexus client contract v1

Repo Manager consumes SBOM Nexus; it does not implement a second scanner,
snapshot store, freshness model, licence classifier, or catch-up scheduler.
This contract pins the boundary used by `RMGR-WP-0011`.

## Authority modes

| Mode | Surface | Authoritative | Persisted | Advances Nexus state |
| --- | --- | --- | --- | --- |
| Local preview | `rmgr sbom scan|licence-report` → `sbom-nexus scan` | no | no | no |
| Service operation | configured SBOM Nexus HTTP client | yes | Nexus decides | yes, according to the route outcome |

Every compatibility-command result carries:

```json
{
  "repo_manager_context": {
    "mode": "local-preview",
    "authoritative": false,
    "persisted": false,
    "advances_last_attempt_at": false,
    "advances_last_success_at": false,
    "creates_snapshot_history": false
  }
}
```

Writing preview JSON to a file creates optional local evidence only. It does
not turn the result into an authoritative snapshot or ingest receipt.

## Pinned snapshot envelope

Repo Manager accepts `schema: sbom-nexus.snapshot.v1`. Additive fields are
compatible. An unknown schema or omission of any of these fields is a contract
error: `schema`, `ok`, `repo_slug`, `source_revision`, `generated_at`,
`entry_count`, `entries`, `sources`, `licence_report`, and `errors`.

Repo Manager may project the existing licence-report compatibility shape from
that envelope. It must not recalculate licence groups or copyleft signals.

## Authoritative service routes

The production client may consume these Nexus-owned routes without depending
on Nexus tables or migrations:

| Purpose | Route |
| --- | --- |
| Upsert repository projection | `PUT /repositories/{repo_slug}` |
| Read repository projections | `GET /repositories/` |
| Persist scan outcome | `POST /sbom/{repo_slug}/ingest` |
| Persist terminal skip outcome | `POST /sbom/{repo_slug}/skip` |
| Read latest repository SBOM | `GET /sbom/{repo_slug}` |
| Read immutable snapshot detail | `GET /sbom/snapshots/{snapshot_id}` |
| Read licence report | `GET /sbom/report/licences/` |

Calls use a bounded timeout and surface deterministic transport, HTTP, and
contract errors. Credentials enter only through the platform runtime path and
must never appear in files, command output, or logs.

## Authoritative client usage

The Python client requires `SBOM_NEXUS_URL`. `SBOM_NEXUS_TIMEOUT_SECONDS`
defaults to 30 seconds and is bounded to 0.1–300 seconds. An optional
`SBOM_NEXUS_TOKEN` may be injected at runtime; its value is excluded from
configuration representations and all structured errors.

```python
from repo_manager.sbom_client import SBOMNexusClient, SBOMNexusConfig

client = SBOMNexusClient(SBOMNexusConfig.from_environment())
client.upsert_repository(
    "example",
    nexus_checkout_path="/srv/controlled/example/abc123",
    active=True,
)
receipt = client.ingest_repository(
    "example",
    expected_source_revision="abc123",
    operation_id="stable-operation-id",
)
latest = client.latest_snapshot("example")
report = client.licence_report()
```

The client URL-escapes repository slugs, accepts only object responses with the
pinned route-specific fields, and adds an `authoritative-service` context. It
does not retry mutations automatically: a timeout or server failure can occur
after Nexus commits. Structured errors therefore expose
`mutation_may_have_committed`; callers must resolve the stable operation id or
read the resulting snapshot before deciding whether to retry.

When an expected source revision is supplied, an `ingested` receipt for any
other revision fails closed as `source_revision_mismatch` and explicitly notes
that the mutation may already have committed. The checkout path sent to Nexus
is Nexus-local controlled-source identity, never authorization to mount a
workstation path into the cluster.

## Forgejo archive source-reference projection

The `CUST-WP-0064` v1 source mechanism is available through a read-only
resolution command:

```bash
rmgr sbom source-ref --path /path/to/checkout --slug example
```

Repo Manager reads the selected Git remote only to normalize identity. It then
uses the anonymous Forgejo API—not local `HEAD`, the working tree, or a cached
remote-tracking ref—to read repository visibility, default branch, and its full
40-character commit SHA. The result contains `kind: forgejo-archive-v1`, exact
`coulomb/<slug>` identity, `revision`, `observed_ref`, and a canonical UTC
`observed_at`.

V1 returns `supported: false` and no `source_ref` for a missing remote,
non-Coulomb identity, slug mismatch, private repository, unavailable Forgejo
record, invalid branch response, or unresolved full SHA. It never falls back
to a workstation path or local revision.

Projection is an explicit mutation and requires both service configuration and
confirmation:

```bash
export SBOM_NEXUS_URL=https://sbom-nexus.example
rmgr sbom source-ref --path /path/to/checkout --slug example \
  --project --confirm-authoritative
```

The projection sends `checkout_path: null` plus the structured source reference.
It succeeds only when Nexus returns the exact same `source_ref`; an older server
that silently ignores the additive field fails closed. This makes the command a
direct readiness probe for the SBOM Nexus side of `CUST-WP-0064`.

## Repository source identity and provenance

Repo Manager remains authoritative for repository slug, active state,
checkout/source identity, and Git revision. An authoritative scan request must
refer to a controlled source artifact or checkout pinned to that revision. It
must not infer identity from a path string or repository name, and it must not
mount a workstation filesystem into the cluster.

`CUST-WP-0064` owns the coordinated source-input topology. Until that topology
is live, local checkout scans remain previews even when their Git revision is
known. SBOM Nexus alone records the resulting authoritative snapshot and
attempt/success history.