Offline, encrypted secrets for AI agents. Your .env holds addresses, not values. mcpv run hands the real values to one process and masks them in everything it prints.
$ curl -fsSL https://raw.githubusercontent.com/mcpmastersh/mcpv/main/install.sh | sh
Node.js 20+. One file on your PATH. Zero runtime dependencies.
# Addresses, not values. Paste it, commit it, # let an agent read it. DATABASE_URL=mcpm://acme/api/dev/DATABASE_URL STRIPE_KEY=mcpm://acme/api/dev/STRIPE_KEY OPENAI_API_KEY=mcpm://acme/api/dev/OPENAI_API_KEY PORT=3000
$ mcpv check ✓ 3 references resolve in mcpm://acme/api/dev $ mcpv run -- npm run dev > acme-api@1.4.0 dev > node server.js db postgres://app:[redacted]@db:5432 stripe key=[redacted] mode=test ✓ listening on :3000
Works with any coding agent that runs a shell
Your agent reads addresses on the way in and redactions on the way out. The real value only exists inside one process, in memory.
Scroll the drawing sideways →
mcpm:// addresses, not values. Paste it, commit it, let an agent read it.There is no get and no reveal. On purpose. Values only ever go into a child process's environment.
mcpv stores each value, then rewrites the file so it holds mcpm:// references instead. It shows what it would store before anything is written.
--only picks which keys to movePORT stays as-is$ mcpv import .env --into mcpm://acme/api/dev \ --only DATABASE_URL,STRIPE_KEY --rewrite ✓ stored 2 secrets in mcpm://acme/api/dev ✓ rewrote .env · 2 references, 1 plain value
Arguments end up in shell history, in ps and in agent transcripts. mcpv only accepts values from a hidden prompt or stdin, so setting a secret needs you.
pbpaste | mcpv set …2 with the fix$ mcpv set mcpm://acme/api/dev/OPENAI_API_KEY Value (hidden): •••••••••••••••••••• ✓ saved OPENAI_API_KEY $ mcpv set acme/api/dev ✗ "acme/api/dev" isn't a full address yet. → mcpv set mcpm://acme/api/dev/<KEY>
run resolves references and injects values into that one child's environment. It scans stdout and stderr and replaces every secret with [redacted], even when a value is split across two writes.
./.env, --env-file or a whole --env environment$ mcpv run -- npm test $ mcpv run --env mcpm://acme/api/prod -- ./migrate.sh migrating postgres://app:[redacted]@prod-db ✓ 4 migrations applied
An agent can see what's missing and ask you to add it. It can search across every environment without touching a single value.
--json on list, check and doctor$ mcpv list --search stripe --environment prod mcpm://acme/api/prod/STRIPE_KEY mcpm://acme/billing/prod/STRIPE_WEBHOOK_SECRET $ mcpv check ✗ 1 missing: mcpm://acme/api/dev/SENTRY_DSN → ask the user to run: mcpv set mcpm://acme/api/dev/SENTRY_DSN
Same format as mcpmaster Cloud Agent Secrets, so a .env of references works with either one.
Case and the scheme are repaired. A trailing slash is just punctuation.
mcpv set Acme/API/Dev/STRIPE_KEYStop at any level to list what lives under it.
mcpv list acme/apiIn a terminal, it prompts for missing pieces and offers what already exists.
mcpv set acme/api → pick env, keyBrowse environments and key names, add or replace values, import a .env and check that references resolve. It runs only while you use it.
mcpm:// address into any box and it splitsPaste it into Claude Code, Codex, Cursor or any coding agent. It installs mcpv, moves your .env into the vault and saves a skill so later sessions know the rules.
curl -fsSL https://raw.githubusercontent.com/mcpmastersh/mcpv/main/install.sh | MCPV_SKILL=1 sh
Set up mcpv, an offline secrets vault, so you can use my API keys without ever seeing them. 1. Install it (needs Node 20+; no sudo): curl -fsSL https://raw.githubusercontent.com/mcpmastersh/mcpv/main/install.sh | MCPV_SKILL=1 sh Then run `mcpv --version` and `mcpv init`. 2. Read the skill it saved (~/.claude/skills/mcpv/SKILL.md, or run `mcpv help`) before doing anything else. 3. If I have a .env, ask me first, then run: mcpv import .env --into mcpm://<workspace>/<project>/<environment> --rewrite 4. Check and run my app: `mcpv check`, then `mcpv run -- <my dev command>`. Rules: - Never print, log, commit or ask me for a secret value. Refer to secrets by their mcpm:// address. - There is no command to reveal a value, on purpose. Do not look for a workaround. - To add a key, tell me to run `mcpv set mcpm://<workspace>/<project>/<environment>/<KEY>` and type it at the hidden prompt. - Do not guess flags. Run `mcpv help <command>` and use what it lists. - If a step fails, quote what it printed and give me the next thing to try.
One encrypted file on your machine. On its own, vault.json is only ciphertext plus key names, in a backup, a synced folder or a stray commit.
A fresh IV per value, with its own address bound in as authenticated data. Move, edit or mis-key a ciphertext and it fails loudly.
The master key sits in macOS Keychain or Linux Secret Service, otherwise a 0600 key file. In CI, set MCPV_KEY.
No command prints a value and no page of mcpv ui shows one. Values only flow into a child's environment.
Loopback only, Host header checked, per-run token, strict CSP, no cross-origin or non-JSON writes, idle shutdown.
run masks resolved values in stdout and stderr, even across split writes. --no-mask for interactive programs.
Vault directory is 0700, files are 0600 and written atomically. The child never inherits MCPV_KEY.
Any process running as your user, an agent's shell included, could run mcpv run --no-mask -- printenv, read the key file or ask the keychain. Masking catches accidents, not a process that sets out to leak a value.
For a hard boundary, run the agent as a different OS user or in a container with no access to the vault. mcpv says this plainly instead of pretending otherwise.
mcpmaster is one local MCP endpoint for every API and MCP server you use. Agents see one execute tool instead of a thousand schemas, and credentials stay out of their context.
$ mcpmaster add https://api.github.com/openapi.json \ --bearer --token-env GITHUB_TOKEN ✓ github · openapi · 1,081 tools $ mcpmaster connect claude-code | sh ✓ Claude Code now sees 1 tool: execute
mcpv is the offline one. Cloud Agent Secrets uses the same mcpm:// addresses, so the same .env works with both, plus workspaces, roles and an audit trail.
Free. One encrypted file on your machine.
Hosted at mcpmaster.sh. Nothing to install.
mcpm:// format, same .envAnything else? Open an issue on GitHub.
Because anything printed can land in a transcript, a log or a commit. mcpv has no get and no reveal. If you need a value, it's wherever you got it from. Your app gets it through mcpv run.
No. No server, no account, no network. One encrypted file in ~/.mcpv and a master key in your OS keychain.
Set MCPV_KEY to the 64-hex-character master key. It overrides the vault's key store, and the child process never receives it.
Yes. import { Vault } from "@mcpmastersh/mcpv", then Vault.open().resolveKey("mcpm://…") resolves a value in memory for your own code.
mcpv is offline and personal. Cloud Agent Secrets is hosted and shared with your team, with roles, audit and revocation. Both read the same mcpm:// addresses.