Artifact Store MCP Server

Governed artifact registry for ADK-Rust Enterprise agents. Content-immutable, versioned, provenance-linked, hash-verified artifacts with policy-driven lifecycle.

Key Principles

• Content-immutable — updates create new versions, never overwrite
• Provenance-linked — every artifact tracks its lineage
• Hash-verified — SHA-256 integrity on every version
• Policy-driven lifecycle — retention classes prevent premature deletion
• Redaction by derivation — redacted copies are new artifacts, originals preserved

Tools (15)

| Tool | Purpose | Risk Class | |------|---------|------------| | write_artifact | Store a generated artifact | Internal write | | create_artifact_version | Add new version to existing artifact | Internal write | | read_artifact | Read content (policy-gated) | Read-only | | list_artifacts | List artifacts by folder, session, class | Read-only | | list_folders | Browse workspace folder hierarchy | Read-only | | get_artifact_metadata | Inspect provenance, retention, hash | Read-only | | verify_artifact_integrity | Validate SHA-256 hash | Read-only | | get_artifact_lineage | Trace provenance chain | Read-only | | export_artifact_package | Bundle artifacts for audit/delivery | Read-only | | derive_artifact | Create artifact derived from another | Internal write | | redact_artifact | Create redacted derived copy | Internal write | | link_artifacts | Add provenance edge | Internal write | | set_retention_class | Update retention policy | Internal write | | request_artifact_access | Request access to gated artifact | External write | | delete_artifact_if_allowed | Delete only if retention permits | Internal write |

Example Prompts & Outputs

Store a report

Prompt: "Save this analysis report as a session artifact"

Tool call: write_artifact

{
  "name": "quarterly-analysis.json",
  "folder_path": "/reports/2026-Q2",
  "content_base64": "eyJyZXZlbnVlIjogIjEuMk0iLCAiZ3Jvd3RoIjogIjE1JSJ9",
  "mime_type": "application/json",
  "artifact_class": "session_output",
  "retention_class": "standard",
  "tags": ["finance", "Q2-2026"]
}

Output:

{
  "artifact_id": "art_c2a2bcf2f86f48a88eba7168612e2904",
  "version_id": "artv_b9c87a30425843ff8837672beee05b37",
  "status": "created"
}

Inspect an artifact

Prompt: "Show me the metadata for that report"

Tool call: get_artifact_metadata

{ "artifact_id": "art_c2a2bcf2f86f48a88eba7168612e2904" }

Output:

{
  "artifact_id": "art_c2a2bcf2f86f48a88eba7168612e2904",
  "folder_path": "/reports/2026-Q2",
  "name": "quarterly-analysis.json",
  "artifact_class": "session_output",
  "owner": "system",
  "session_id": "ses_test_001",
  "risk_level": "low",
  "retention_class": "standard",
  "status": "active",
  "current_version": {
    "version_id": "artv_b9c87a30425843ff8837672beee05b37",
    "version_number": 1,
    "mime_type": "application/json",
    "size_bytes": 42,
    "sha256": "da09a1f13a3d728bccc87bc001a2950163c8a1cd96161a0390da1660467ffb86",
    "created_at": "2026-05-23T11:29:42Z"
  },
  "tags": ["finance", "Q2-2026"],
  "created_at": "2026-05-23T11:29:42Z",
  "updated_at": "2026-05-23T11:29:42Z"
}

Verify integrity

Prompt: "Verify the integrity of this artifact"

Tool call: verify_artifact_integrity

{ "artifact_id": "art_c2a2bcf2f86f48a88eba7168612e2904" }

Output:

{
  "artifact_id": "art_c2a2bcf2f86f48a88eba7168612e2904",
  "version_id": "artv_b9c87a30425843ff8837672beee05b37",
  "expected_sha256": "da09a1f13a3d728bccc87bc001a2950163c8a1cd96161a0390da1660467ffb86",
  "actual_sha256": "da09a1f13a3d728bccc87bc001a2950163c8a1cd96161a0390da1660467ffb86",
  "integrity_valid": true,
  "size_bytes": 42
}

Derive a summary from a source artifact

Prompt: "Create an executive summary derived from the quarterly report"

Tool call: derive_artifact

{
  "source_artifact_id": "art_c2a2bcf2f86f48a88eba7168612e2904",
  "name": "executive-summary.md",
  "content_base64": "IyBRMiBTdW1tYXJ5CgpSZXZlbnVlIGdyZXcgMTUlIHRvICQxLjJNLg==",
  "mime_type": "text/markdown"
}

Output:

{
  "derived_artifact_id": "art_aa3a2a0a5c3744988393209258b32a15",
  "source_artifact_id": "art_c2a2bcf2f86f48a88eba7168612e2904"
}

Trace provenance

Prompt: "Show me the lineage of the quarterly report"

Tool call: get_artifact_lineage

{ "artifact_id": "art_c2a2bcf2f86f48a88eba7168612e2904" }

Output:

{
  "artifact_id": "art_c2a2bcf2f86f48a88eba7168612e2904",
  "derived_from": [],
  "derived_to": [
    {
      "edge_id": "edge_98637dc4d55c40aa9c03e238551230f9",
      "edge_type": "derived_from",
      "from_artifact_id": "art_c2a2bcf2f86f48a88eba7168612e2904",
      "to_artifact_id": "art_aa3a2a0a5c3744988393209258b32a15",
      "created_at": "2026-05-23T11:30:26Z"
    }
  ]
}

Retention enforcement

Prompt: "Mark this as an audit artifact and try to delete it"

Tool call: set_retention_class

{ "artifact_id": "art_c2a2bcf2f86f48a88eba7168612e2904", "retention_class": "audit" }

Output:

{ "artifact_id": "art_c2a2bcf2f86f48a88eba7168612e2904", "retention_class": "audit" }

Tool call: delete_artifact_if_allowed

{ "artifact_id": "art_c2a2bcf2f86f48a88eba7168612e2904" }

Output:

Deletion blocked: retention class Audit prevents deletion

Redact sensitive content

Prompt: "Create a redacted version of this transcript for sharing"

Tool call: redact_artifact

{
  "artifact_id": "art_transcript_001",
  "redacted_content_base64": "VHJhbnNjcmlwdDogW1JFREFDVEVEXSBkaXNjdXNzZWQgcHJpY2luZy4=",
  "mime_type": "text/plain",
  "fields_removed": ["customer_name", "phone_number", "account_id"]
}

Output:

{
  "redacted_artifact_id": "art_f7b2c1d4e5a6...",
  "source_artifact_id": "art_transcript_001"
}

Export audit package

Prompt: "Bundle these artifacts for the compliance audit"

Tool call: export_artifact_package

{
  "artifact_ids": [
    "art_c2a2bcf2f86f48a88eba7168612e2904",
    "art_aa3a2a0a5c3744988393209258b32a15"
  ]
}

Output:

{
  "package_id": "pkg_4f8a2b1c...",
  "artifact_count": 2,
  "artifacts": [
    { "artifact_id": "art_c2a2...", "name": "quarterly-analysis.json", ... },
    { "artifact_id": "art_aa3a...", "name": "executive-summary.md", ... }
  ]
}

Backends

| Layer | Backend | Feature Flag | |-------|---------|-------------| | Blob storage | Local filesystem | local (default) | | Blob storage | AWS S3 | s3 | | Blob storage | Google Cloud Storage | gcs | | Metadata | In-memory (dev/testing) | Always available |

Installation

Build from source

git clone https://github.com/zavora-ai/mcp-artifact-store
cd mcp-artifact-store
cargo build --release --features all-backends

Claude Desktop

{
  "mcpServers": {
    "artifact-store": {
      "command": "/path/to/mcp-artifact-store",
      "env": { "ARTIFACT_STORE_PATH": "~/artifacts" }
    }
  }
}

Kiro

Add to .kiro/settings/mcp.json:

{
  "mcpServers": {
    "artifact-store": {
      "command": "/path/to/mcp-artifact-store",
      "env": { "ARTIFACT_STORE_PATH": "~/artifacts" }
    }
  }
}

Codex / Cursor / Windsurf / Antigravity / Open Code

Same pattern — point command to the binary and set ARTIFACT_STORE_PATH.

Configuration

| Variable | Description | Default | |----------|-------------|---------| | ARTIFACT_STORE_PATH | Local blob storage root | ./artifacts | | AWS_REGION | S3 region (s3 feature) | — | | ARTIFACT_S3_BUCKET | S3 bucket name | — | | GCP_PROJECT_ID | GCP project (gcs feature) | — | | ARTIFACT_GCS_BUCKET | GCS bucket name | — |

Artifact Classes

| Class | Examples | |-------|----------| | session_output | Reports, transcripts, screenshots, JSON | | agent_evidence | Tool result snapshots, cited documents | | governance_evidence | Policy decisions, approval records, audit packs | | payment_evidence | Receipts, intents, ledger snapshots | | build_output | Generated code, SBOMs, deploy bundles | | template_asset | Fixtures, skill lockfiles, workflow templates | | memory_export | Recall snapshots, redacted profile exports |

Retention Classes

| Class | Default Retention | Deletable? | |-------|-------------------|------------| | ephemeral | Hours/days | ✅ Yes | | standard | 90 days | ✅ Yes | | session | 30–180 days | ✅ Yes | | pii_restricted | Short + redaction | ⚠️ Gated | | payment_evidence | Legal retention | ❌ No | | audit | 1–7 years | ❌ No | | build_release | Tied to release | ❌ No |

Provenance Edge Types

| Edge | Meaning | |------|---------| | derived_from | Artifact B was created from artifact A | | redacted_from | Artifact B is a redacted copy of A | | bundled_into | Artifact A was included in package B | | exported_from | Artifact B was exported from system A | | generated_by | Artifact was generated by a tool/agent | | validated_by | Artifact was validated by a policy check | | approved_by | Artifact was approved by a human/gate | | evidence_for | Artifact serves as evidence for a decision |

Documentation

| Document | Description | |----------|-------------| | SPEC.md | Full design specification | | CHANGELOG.md | Version history | | mcp-server.toml | ADK-Rust Enterprise registry manifest | | CONTRIBUTING.md | Development guidelines | | SECURITY.md | Vulnerability reporting |

Contributing

See CONTRIBUTING.md for development setup and guidelines.

Contributors

|
_{James Karanja Maina} | |:---:|

License

Apache-2.0 — see LICENSE for details.

Part of the ADK-Rust Enterprise MCP server ecosystem.

Built with ❤️ by Zavora AI