VaultProof vs Doppler vs HashiCorp Vault — Which One for API Keys?

Quick comparison

Before we dive into the details, here's the high-level view:

HashiCorp Vault: powerful but complex

HashiCorp Vault is the industry standard for secrets management in enterprise environments. It handles everything from database credentials to PKI certificates to cloud IAM.

What it does well:

• Dynamic secrets — generates short-lived credentials on the fly
• Encryption as a service — encrypt/decrypt without managing keys
• Audit logging — every access is recorded
• Policy engine — fine-grained access control
• Self-hosted — runs on your infrastructure

The catch:

• It requires infrastructure. You need to run, maintain, and secure Vault servers. HA setup requires Consul or Raft. This is a DevOps project, not a developer tool.
• It costs real money. HCP Vault starts at $1.58/hr (~$1,150/mo). Self-hosted is "free" but requires engineer time.
• Integration isn't simple. You need the Vault SDK, a Vault token, and code to fetch secrets at runtime. There's no "change one line" option.
• It sees your keys in plaintext. When you store a secret in Vault, the Vault server decrypts and re-encrypts it. At runtime, it returns the plaintext key. A compromised Vault server means all secrets are exposed.

Vault is the right choice for enterprises managing thousands of dynamic credentials across complex infrastructure. It's overkill for a developer who needs to store 5 API keys securely.

Doppler: developer-friendly, but they see your keys

Doppler is the developer's secrets manager. It's well-designed, has great DX, and integrates with everything from Vercel to AWS to GitHub Actions.

What it does well:

• doppler run — injects env vars at runtime, like VaultProof's CLI
• Environment management — dev, staging, production configs
• Team sharing — centralized secrets for your whole team
• Native integrations — Vercel, Netlify, Fly.io, etc.
• Audit logs and version history

The catch:

• Doppler sees your keys in plaintext. When you store a secret, Doppler's servers have it. Their team can technically access it. A breach of Doppler means your keys are exposed. You're trusting their security team with your most sensitive credentials.
• $23/user/month adds up. For a team of 10, that's $230/mo just for secrets management. And every team member needs access.
• No proxy URL option. You can't just swap a base URL and be done. You need to use doppler run or their SDK integrations.

Doppler is great for teams who trust their secrets provider. If "they promise not to look at our keys" is good enough for your threat model, Doppler is a solid choice.

VaultProof: keys are split — we can't see them

VaultProof takes a fundamentally different approach. Instead of storing your key and promising not to look at it, we split it using Shamir's Secret Sharing so that no single party ever has the complete key.

How it works:

• When you store a key, it's split into 3 shares in your browser (client-side)
• Share 1 is encrypted and stored by VaultProof
• Share 2 goes to your browser's local storage
• Share 3 is derived from your password
• The full key is never sent to our servers

At runtime:

• Your app calls VaultProof's proxy URL
• The proxy reconstructs the key from shares in a Cloudflare Worker (edge, ephemeral memory)
• The key is injected into the upstream API call
• The key is never logged, stored, or returned

What this means:

• A VaultProof database breach reveals only encrypted partial shares — useless without the other shares
• VaultProof employees mathematically cannot access your keys
• Zero-knowledge proofs (Noir) let you verify a key is valid without revealing it
• 1-line integration — swap baseURL and you're done
• Free tier — 3 keys, 10,000 proxy calls/month. Starter at $5/mo, Pro at $20/mo.

When to use which

The bottom line: Vault is for infrastructure teams. Doppler is for dev teams who trust their provider. VaultProof is for developers who trust no one — including us.