docs: add tutorial for attesting large documents with Evidence Vault

config/navigation.json

@@ -71,7 +71,8 @@
               "group": "Attesting",
               "pages": [
                 "tutorials/attest_snyk",
-                "tutorials/custom-attestation-ctrf"
+                "tutorials/custom-attestation-ctrf",
+                "tutorials/attest_large_documents"
               ]
             },
             {

tutorials/attest_large_documents.md

@@ -0,0 +1,91 @@
+---
+title: "Attesting large documents (SBOMs, SARIF, vulnerability reports)"
+description: "How to attest large security and compliance reports in Kosli using summary attestations and the Evidence Vault"
+---
+
+In this tutorial, we will attest a large security report to Kosli using a lightweight summary for compliance evaluation, with the full document preserved in the Evidence Vault for audit purposes.
+By the end, you will have a Kosli attestation that captures the key facts from your report — vulnerability counts, severity levels, pass/fail status — and links to the full file for audit access.
+
+This two-part approach keeps attestation payloads focused on what compliance rules need to evaluate, while ensuring the raw evidence remains available.
+
+## Prerequisites
+
+* [Install Kosli CLI](/getting_started/install).
+* [Get a Kosli API token](/getting_started/service-accounts).
+* A Kosli flow and trail to attest to — follow the [Getting started guide](/getting_started/flows) if you need one.
+* A report file to attest (e.g. an SBOM in JSON format, or a SARIF vulnerability report).
+
+## Step 1: Create a summary attestation type
+
+Define a custom attestation type that captures the key facts from your report. In this example we use a vulnerability report distilled into a summary JSON file:
+
+```json
+{
+  "critical": 0,
+  "high": 2,
+  "medium": 14,
+  "low": 37
+}
+```
+
+Create an attestation type that enforces a zero-critical-findings rule:
+
+```shell
+kosli create attestation-type vulnerability-summary \
+  --description "Summary of vulnerability scan findings" \
+  --jq '.critical == 0'
+```
+
+You should see: `attestation-type vulnerability-summary was created`.
+
+You can verify it with:
+
+```shell
+kosli get attestation-type vulnerability-summary
+```
+
+## Step 2: Distill your report into a summary
+
+Use `jq` (or any other tool) to extract the fields you care about from your full report and write them to a summary file.
+
+For example, if your tool produces a SARIF file, you might count findings by severity and write the result to `vuln-summary.json`.
+
+The exact transformation will depend on your tool's output format. The goal is a small JSON object that your attestation type's rules can evaluate.
+
+## Step 3: Attest the summary and attach the full report
+
+Use `--attachments` to upload the full report to the Evidence Vault alongside the summary attestation:
+
+```shell
+kosli attest custom \
+  --type vulnerability-summary \
+  --name security-scan \
+  --flow <your-flow-name> \
+  --trail <your-trail-name> \
+  --attestation-data vuln-summary.json \
+  --attachments full-report.sarif
+```
+
+Kosli will:
+
+* Evaluate the jq rule against `vuln-summary.json` to determine compliance.
+* Store `full-report.sarif` in the Evidence Vault, linked to this attestation.
+
+## Step 4: Verify the attestation
+
+```shell
+kosli get attestation <attestation-name> \
+  --flow <your-flow-name> \
+  --trail <your-trail-name>
+```
+
+The attestation record will show the compliance status and include a link to the attached file in the Evidence Vault.
+
+## What you've accomplished
+
+You have attested a security report to Kosli using a lightweight summary for compliance evaluation, with the full document preserved in the Evidence Vault for audit purposes.
+
+From here you can:
+* Read the [`kosli create attestation-type`](/client_reference/kosli_create_attestation-type) reference for all available options.
+* Read the [`kosli attest custom`](/client_reference/kosli_attest_custom) reference for attesting to artifacts.
+* Review [naming conventions for attestation types](/implementation_guide/phase_2/plan_organizational_structure/naming_conventions/attestation_types).