# HashiCorp Vault Setup

Phase 2 of AgentIdP optionally stores credential secrets in [HashiCorp Vault](https://www.vaultproject.io/) KV v2 instead of bcrypt hashes in PostgreSQL. This guide covers:

- Dev mode quickstart
- Production Vault configuration
- Migration from bcrypt to Vault

Vault is **entirely optional**. If `VAULT_ADDR` is not set, AgentIdP operates in bcrypt mode (identical to Phase 1 behaviour).

---

## How Vault integration works

When enabled:

1. `POST /api/v1/agents/{agentId}/credentials` — the plain-text secret is written to Vault at `{mount}/data/agentidp/agents/{agentId}/credentials/{credentialId}`. Only the Vault path is stored in PostgreSQL (`credentials.vault_path`). No bcrypt hash is written.
2. `POST /api/v1/token` — the submitted `client_secret` is compared against the value read from Vault (constant-time comparison). No bcrypt is involved.
3. `POST /api/v1/agents/{agentId}/credentials/{credentialId}/rotate` — a new Vault version is written (KV v2 versioning). The path is unchanged; the old version is retained in Vault history.
4. `DELETE /api/v1/agents/{agentId}/credentials/{credentialId}` — all versions of the secret are permanently deleted from Vault.

**Coexistence**: Credentials created before Vault was enabled keep their bcrypt hash and continue to work. New credentials use Vault. Both paths coexist until all pre-Vault credentials are rotated.

---

## Dev mode quickstart

The fastest way to get Vault running locally:

```bash
# Pull and start Vault in dev mode (in-memory, auto-unsealed)
docker run --rm -d \
  --name vault-dev \
  -p 8200:8200 \
  -e VAULT_DEV_ROOT_TOKEN_ID=dev-root-token \
  hashicorp/vault:1.15 server -dev

# Verify it is running
curl http://127.0.0.1:8200/v1/sys/health | jq .
```

Add to your `.env`:

```
VAULT_ADDR=http://127.0.0.1:8200
VAULT_TOKEN=dev-root-token
VAULT_MOUNT=secret
```

> **Note:** The `.env.example` file uses `VAULT_KV_MOUNT` as the variable name. The application
> reads both `VAULT_KV_MOUNT` and `VAULT_MOUNT` — prefer `VAULT_KV_MOUNT` in new configurations
> for consistency with the current `.env.example`.

The KV v2 secrets engine is automatically enabled at `secret/` in dev mode. No further configuration is needed.

> **Warning**: Dev mode stores everything in memory. Data is lost when the container stops. Do not use dev mode in production.

---

## Production Vault configuration

### 1. Enable KV v2 secrets engine

```bash
vault secrets enable -path=secret kv-v2
```

Or use a custom mount path:

```bash
vault secrets enable -path=agentidp kv-v2
# Set VAULT_MOUNT=agentidp in your .env
```

### 2. Create a policy for AgentIdP

```hcl
# agentidp-policy.hcl
path "secret/data/agentidp/*" {
  capabilities = ["create", "read", "update", "delete"]
}

path "secret/metadata/agentidp/*" {
  capabilities = ["delete"]
}
```

Apply the policy:

```bash
vault policy write agentidp agentidp-policy.hcl
```

### 3. Create a service token

```bash
vault token create \
  -policy=agentidp \
  -ttl=8760h \
  -renewable=true \
  -display-name="agentidp-service"
```

Copy the `token` field from the output and set it as `VAULT_TOKEN` in your environment.

### 4. Token renewal

Service tokens expire unless renewed. Set up a scheduled renewal before the TTL expires:

```bash
# Renew with a new 720-hour (30-day) lease
vault token renew -increment=720h <token>
```

In Kubernetes, use Vault Agent Injector or the Vault Secrets Operator to handle renewal automatically.

---

## Running migration 005

After configuring Vault, run the migration to add the `vault_path` column:

```bash
npm run db:migrate
```

Verify the migration:

```sql
SELECT column_name, data_type, is_nullable
FROM information_schema.columns
WHERE table_name = 'credentials'
ORDER BY ordinal_position;
```

You should see a `vault_path` column with `data_type = text` and `is_nullable = YES`.

---

## Migrating existing credentials to Vault

Existing credentials (with `vault_path IS NULL`) continue to work via bcrypt until they are rotated. To migrate a credential:

```bash
# Rotate the credential — this writes the new secret to Vault
curl -s -X POST http://localhost:3000/api/v1/agents/$AGENT_ID/credentials/$CRED_ID/rotate \
  -H "Authorization: Bearer $TOKEN" | jq .
```

The response includes the new `clientSecret` (store it immediately). After rotation, `vault_path` is set and the bcrypt hash is cleared.

To migrate all credentials for an agent in bulk, rotate them one by one using the API.

---

## Verifying Vault secrets

After generating a credential with Vault enabled, verify the secret was written:

```bash
vault kv get secret/agentidp/agents/$AGENT_ID/credentials/$CRED_ID
```

Expected output:

```
====== Secret Path ======
secret/data/agentidp/agents/<agentId>/credentials/<credentialId>

======= Metadata =======
Key                Value
---                -----
created_time       2026-03-28T...
version            1

====== Data ======
Key             Value
---             -----
clientSecret    <the secret>
```

---

## Troubleshooting

### `VAULT_WRITE_ERROR` on credential generation

- Verify Vault is running: `curl $VAULT_ADDR/v1/sys/health`
- Verify the token has write access: `vault token capabilities $VAULT_TOKEN secret/data/agentidp/test`
- Check Vault audit logs: `vault audit list`

### `VAULT_READ_ERROR` on token issuance

- Verify the `vault_path` stored in PostgreSQL matches the actual Vault path
- Check the token has read access to `secret/data/agentidp/*`

### Vault is down — what happens?

If Vault is unreachable, credential generation and token issuance for Vault-backed credentials will fail with a `500` error. Credentials created before Vault was enabled (bcrypt mode) continue to work.

For high availability, run Vault in HA mode with an integrated Raft storage backend. See [Vault HA documentation](https://developer.hashicorp.com/vault/docs/concepts/ha).