mcp-credentials-vault 1.1.0

Credentials Vault MCP server for ADK-Rust Enterprise — scoped, auditable credential access with pluggable vault backends
Documentation
# Credentials Vault MCP Server

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Scoped, auditable credential access for [ADK-Rust Enterprise](https://enterprise.adk-rust.com) agents. Provides 8 MCP tools over 5 pluggable vault backends — **never exposes raw secrets to LLM context**.

## Architecture

<p align="center">
  <img src="https://raw.githubusercontent.com/zavora-ai/mcp-credentials-vault/main/docs/architecture.svg" alt="Credentials Vault MCP Architecture" width="800"/>
</p>

## Key Principles

- **Zero secret exposure** — raw secrets never reach LLM context. Tools return handles and short-lived tokens only.
- **Scoped access** — credentials declare which agents, skills, and MCP servers can use them.
- **Full audit trail** — every access, denial, rotation, and revocation is logged.
- **Pluggable backends** — use one or many vault backends simultaneously.
- **Registry-ready** — ships with `mcp-server.toml` for automatic ADK-Rust Enterprise onboarding.

## Tools

| Tool | Purpose | Risk Class |
|------|---------|------------|
| `list_credentials` | List credential metadata (never raw values) | Read-only |
| `get_credential_metadata` | Inspect owner, scope, expiry, rotation, risk | Read-only |
| `request_runtime_secret` | Issue scoped runtime handle after policy checks | Identity/Security |
| `request_workload_token` | Mint short-lived OIDC/workload identity token | Identity/Security |
| `rotate_credential` | Rotate secret through approved workflow | Identity/Security |
| `revoke_credential` | Disable compromised or expired credential | Identity/Security |
| `audit_credential_access` | Retrieve access/denial/rotation audit events | Read-only |
| `validate_secret_scope` | Check if an actor can use a credential | Read-only |

## Backends

| Backend | Feature Flag | Use Case |
|---------|-------------|----------|
| HashiCorp Vault | `hashicorp` | Self-hosted, KV v2, dynamic secrets |
| AWS Secrets Manager | `aws` | AWS-native workloads |
| GCP Secret Manager | `gcp` | GCP-native workloads |
| Azure Key Vault | `azure` | Azure-native workloads |
| ADK Vault | `adk-vault` | Platform-managed credentials (default) |
| ADK Platform API | `adk-platform` | ADK-Rust Enterprise centralized management |

## Installation

### Build from source

```bash
git clone https://github.com/zavora-ai/mcp-credentials-vault
cd mcp-credentials-vault
cargo build --release --features all-backends
```

The binary is at `target/release/mcp-credentials-vault`.

### Claude Desktop

Add to `~/Library/Application Support/Claude/claude_desktop_config.json` (macOS) or `%APPDATA%\Claude\claude_desktop_config.json` (Windows):

```json
{
  "mcpServers": {
    "credentials-vault": {
      "command": "/path/to/mcp-credentials-vault",
      "args": [],
      "env": {
        "RUST_LOG": "info"
      }
    }
  }
}
```

### Kiro

Add to your project's `.kiro/settings/mcp.json`:

```json
{
  "mcpServers": {
    "credentials-vault": {
      "command": "/path/to/mcp-credentials-vault",
      "args": [],
      "env": {
        "RUST_LOG": "info"
      }
    }
  }
}
```

### Codex (OpenAI)

Add to `~/.codex/config.json`:

```json
{
  "mcpServers": {
    "credentials-vault": {
      "command": "/path/to/mcp-credentials-vault"
    }
  }
}
```

### Antigravity

Add to your Antigravity workspace MCP configuration:

```json
{
  "servers": [
    {
      "name": "credentials-vault",
      "transport": "stdio",
      "command": "/path/to/mcp-credentials-vault",
      "env": {
        "RUST_LOG": "info"
      }
    }
  ]
}
```

### Open Code

Add to `~/.config/opencode/config.json`:

```json
{
  "mcp": {
    "credentials-vault": {
      "command": "/path/to/mcp-credentials-vault",
      "args": []
    }
  }
}
```

### Cursor

Add to `.cursor/mcp.json` in your project root:

```json
{
  "mcpServers": {
    "credentials-vault": {
      "command": "/path/to/mcp-credentials-vault",
      "args": []
    }
  }
}
```

### Windsurf

Add to `~/.codeium/windsurf/mcp_config.json`:

```json
{
  "mcpServers": {
    "credentials-vault": {
      "command": "/path/to/mcp-credentials-vault",
      "args": []
    }
  }
}
```

### Any MCP Client (Streamable HTTP)

For clients that support HTTP transport, run the server in HTTP mode:

```bash
mcp-credentials-vault --transport http --port 8080
```

Then connect your client to `http://localhost:8080/mcp`.

### Docker

```bash
docker run -p 8080:8080 \
  -e AWS_ACCESS_KEY_ID=$AWS_ACCESS_KEY_ID \
  -e AWS_SECRET_ACCESS_KEY=$AWS_SECRET_ACCESS_KEY \
  -e GOOGLE_APPLICATION_CREDENTIALS=/creds/gcp.json \
  -v ~/.config/gcloud/application_default_credentials.json:/creds/gcp.json \
  ghcr.io/zavora-ai/mcp-credentials-vault:latest
```

## Quick Start

### Installation

```toml
[dependencies]
mcp-credentials-vault = { version = "1.0", features = ["all-backends"] }
```

Or select specific backends:

```toml
[dependencies]
mcp-credentials-vault = { version = "1.0", features = ["aws", "gcp"] }
```

### Running as MCP Server

```rust
use mcp_credentials_vault::{adk_vault::AdkVaultBackend, server::CredentialsVaultServer};
use rmcp::{ServiceExt, transport::stdio};

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let backend = AdkVaultBackend::new(Some("./credentials.json".into()));
    let server = CredentialsVaultServer::new(vec![Box::new(backend)]);
    let service = server.serve(stdio()).await?;
    service.waiting().await?;
    Ok(())
}
```

### Multi-backend Configuration

```rust
use mcp_credentials_vault::{
    adk_vault::AdkVaultBackend,
    aws::AwsBackend,
    gcp::GcpBackend,
    server::CredentialsVaultServer,
};

let server = CredentialsVaultServer::new(vec![
    Box::new(AdkVaultBackend::new(None)),
    Box::new(AwsBackend::new(Some("us-east-1".into())).await),
    Box::new(GcpBackend::new("my-project".into()).await?),
]);
```

## Configuration

### Environment Variables

| Variable | Backend | Purpose |
|----------|---------|---------|
| `ADK_PLATFORM_URL` | ADK Platform | Platform base URL |
| `ADK_PLATFORM_API_KEY` | ADK Platform | API key (`ep_live_xxxx`) |
| `ADK_WORKSPACE_ID` | ADK Platform | Workspace UUID |
| `ADK_VAULT_PATH` | ADK Vault | JSON persistence file path |
| `VAULT_ADDR` | HashiCorp | Vault server URL |
| `VAULT_TOKEN` | HashiCorp | Authentication token |
| `AWS_REGION` | AWS | AWS region |
| `AWS_ACCESS_KEY_ID` | AWS | AWS credentials (or use IAM role) |
| `GCP_PROJECT_ID` | GCP | GCP project ID |
| `AZURE_VAULT_URL` | Azure | Key Vault URL |
| `AZURE_ACCESS_TOKEN` | Azure | Azure AD token |

### MCP Server Manifest

The server ships with `mcp-server.toml` for ADK-Rust Enterprise registry onboarding:

```toml
server_id = "mcp_credentials_vault"
display_name = "Credentials Vault MCP"
version = "1.0.0"
domain = "platform"
risk_level = "critical"
writes_allowed = "gated"
transports = ["stdio", "streamable_http"]
governance_gates = ["policy_evaluation_required", "audit_all_access"]
```

## Security Model

```
Agent requests credential → Scope validation → Policy check → Handle issued
                                                    Runtime worker resolves
                                                    handle to actual secret
                                                    (outside LLM context)
```

1. **Agents never see raw secrets** — only handles with expiry and scope
2. **Scope enforcement** — credentials declare allowed actors
3. **Audit everything** — access, denials, rotations, revocations
4. **Short-lived tokens** — workload tokens expire (default 5 min for runtime, 1 hour for workload)
5. **Governance gates**`rotate` and `revoke` require approval in production

## Testing

```bash
# Build with all backends
cargo build --features all-backends

# Run tests (ADK Vault — no external deps)
cargo test

# Run with real backends (requires credentials)
cargo test --features all-backends

# Run the integration test binary
cargo run --features all-backends
```

## Documentation

| Document | Description |
|----------|-------------|
| [API Reference]docs/api-reference.md | All 8 tools with parameters, returns, and examples |
| [Backends]docs/backends.md | Configuration for each vault backend |
| [Security Model]docs/security-model.md | Zero-exposure architecture and threat model |
| [CHANGELOG.md]CHANGELOG.md | Version history |
| [mcp-server.toml]mcp-server.toml | ADK-Rust Enterprise registry manifest |
| [CONTRIBUTING.md]CONTRIBUTING.md | Development guidelines |
| [SECURITY.md]SECURITY.md | Vulnerability reporting |
| [Rust Docs]https://docs.rs/mcp-credentials-vault | Generated API documentation |

## Contributing

See [CONTRIBUTING.md](CONTRIBUTING.md) for development setup and guidelines.

## Contributors

<!-- ALL-CONTRIBUTORS-LIST:START -->
| [<img src="https://github.com/jkmaina.png" width="80px;" alt=""/><br /><sub><b>James Karanja Maina</b></sub>]https://github.com/jkmaina |
|:---:|
<!-- ALL-CONTRIBUTORS-LIST:END -->

## License

Apache-2.0 — see [LICENSE](LICENSE) for details.

---

Part of the [ADK-Rust Enterprise](https://enterprise.adk-rust.com) MCP server ecosystem.

Built with ❤️ by [Zavora AI](https://zavora.ai)

## Registry Compliance

This server implements the [ADK MCP SDK](https://crates.io/crates/adk-mcp-sdk) contract:

- **HealthCheck** — async health probe for registry monitoring
- **mcp-server.toml** — manifest declaring tools, risk classes, and credentials
- **Structured tracing**`RUST_LOG` env-filter for observability