VERAX

Verax

The body an agent asks before it acts.

Listed on: npm · Glama · MCP Registry · MCP Market · mcp.so · Docker Hub · Zenodo

Verax is an MCP server that sits between an agent and its tools. Every tool call passes a policy gate and leaves a signed decision record before anything runs; every call that ran leaves an effect row that is reconciled against its record afterwards. A refusal is recorded the same way as an approval. A call the policy will not decide alone is held until an operator approves it, at this machine or, with the operator door set up, from another device with a passkey. The ledger stays on the machine the body runs on, and the body opens only when its authorization is configured: there is no default token.

Break it, and we pay. USD 100 for each valid report of a way for the agent's account to get a refused call allowed, run a call with no decision record, or change the service's code, keys or ledger. The budget is USD 500 in total. Terms: SECURITY.md.

By VERAX Teknoloji. Sister projects: Conarium · Tugra · Cedulon. Decision records use the Cedulon record format.

How Verax compares, dated 15 October 2026: of 40 projects that gate, log or approve an agent's tool calls, nine are compared on four questions with a source for every cell, and the page says where Verax falls short: verax-ai.com/compare.html.

See it run

npx @verax-ai/body demo

The recording is the output of one run in a terminal where the approval question was answered y and the amount was typed. That run took about a second; it is played back slowly here so it can be read.

What it prints, without a terminal to answer the approval question:

verax demo

memory.put / memory.get allowed; two signed records

message.send -> ops@blocked.test refused egress-blocked (signed) ref 6c6e4925-b769-4a8b-8fc4-e2443613a5b6

spend 100 minor USD sample-merchant held no terminal to ask, so it stays held (run this in a terminal to be asked)

audit.explain of the refuse finding none trust-root own-key chain and signatures read back

records 5 effects 3 ledger removed on exit (run with --keep to keep it and check it with verax verify)

Not shown here: data masking arrives with a downstream server such as Conarium; statement reconciliation needs a real statement (verax reconcile).

Node 22.6 or newer, @verax-ai/body 0.2.1 or later. The command records an allowed memory write and read, a signed refuse of a message to a host off the policy list, and a payment held for the operator on this machine (approved when the terminal answers y and then types the amount, 100; up to 0.5.0 the demo did not print that second question).

--keep leaves the temporary ledger on disk. verax verify reads it back without a body, as in Read the ledger back without us. To keep it and check it:

npx @verax-ai/body demo --keep

npx -y -p @verax-ai/body verax verify

The same rules, animated

Four short episodes show the same gate, with characters in place of a terminal. They are sample scenarios: the scenes are drawn in three.js and the voices are generated with ElevenLabs.

Episode 1, "$1,850": a payment is held until a person approves it on a phone, and changing one cent in the record breaks its signature.

https://github.com/user-attachments/assets/772ae1c4-2697-47a0-a228-36f0508b0d93

Episode 2, "No rule, no way through": a call with no rule is refused, the same call under a new name is refused again, and both refusals are signed.

https://github.com/user-attachments/assets/4fb86627-3310-4f10-b1a9-059d8fcffb28

Episode 3, "The red lever": an operator halts the body, every later call is refused and signed, and a call that was already running is not cut off.

https://github.com/user-attachments/assets/8d19eed9-3359-46b3-bd77-f2b1b1c4dd75

Episode 4, "Who approved?": a held spend waits for verax approve on the machine, the agent cannot approve it, and the approver's operator id goes into the record.

https://github.com/user-attachments/assets/0b8aade4-a970-4b63-835e-4837e2a39cc9

Connect your agent

Elevated verax install and verax approve run a copy of this program that only an administrator can change; a copy your account can change is refused. On Windows a passkey through the operator door (verax install --operator-door ) approves without an elevated shell; without the door, an elevated CLI approve is the way. It has to be run from a separate administrator account, not this account elevated, because a same-user elevated shell inherits that user's environment variables and PowerShell profile, which the agent can set. Clear NODE_OPTIONS in that shell (Remove-Item Env:NODE_OPTIONS). Start that other account's PowerShell with -NoProfile (an elevated shell otherwise runs your $PROFILE, which your account can change):

npm install -g --prefix "$env:ProgramFiles\verax-cli" @verax-ai/body

& "$env:ProgramFiles\verax-cli\verax.cmd" install

On Linux and macOS, with a root-owned Node (the distribution's /usr/bin/node, or /opt/verax-node/ /bin/node; the installer prints those steps when the Node it was started from can be changed by your account). Do not start an elevated command with env node:

sudo npm install -g --prefix /opt/verax-cli @verax-ai/body

sudo /usr/bin/node /opt/verax-cli/lib/node_modules/@verax-ai/body/dist/cli.js install

The command installs @verax-ai/body from the npm registry into an administrator-owned directory after signature checks, runs that Node, and keeps the ledger under a service account. On Windows the agent token is %ProgramData%\Verax\agent-token\ \agent.token (Administrators and SYSTEM have full control, your SID can read the file and read-execute the directory). On Linux and macOS a child process running as your uid writes ~/.verax/agent.token from its stdin. It prints the Claude Code line that reads that file. Port 8787 taken? verax install --port 8797. Node must be the all-users installer from nodejs.org on Windows; a Node your account can rewrite is refused. On macOS the remedy extracts the official tarball as root into /opt/verax-node (root:wheel, not group- or other-writable). On Linux the same place, /opt/verax-node (root:root), which SELinux labels usr_t. On SELinux systems install requires Node labelled bin_t or usr_t (distribution Node is; a tarball under /usr/local/lib is not) and prints the one-line fix. The service then runs in unconfined_service_t. The service account and the file permissions are the boundary.

Approve a held call with verax approve, or, when the install named an origin with --operator-door, from another device through the operator door with a passkey enrolled by a pairing code from verax operator enroll. The passkey panel (verax desktop) is not released yet. On Windows run the approve from a separate administrator account, not this account elevated, in a -NoProfile PowerShell after Remove-Item Env:NODE_OPTIONS: & "$env:ProgramFiles\verax-cli\verax.cmd" approve. Linux and macOS, naming the root-owned Node: sudo /usr/bin/node /opt/verax-cli/lib/node_modules/@verax-ai/body/dist/cli.js approve or sudo /opt/verax-node/ /bin/node /opt/verax-cli/lib/node_modules/@verax-ai/body/dist/cli.js approve. Uninstall the same way, with uninstall in place of approve.

To try it in your own user, which is not a boundary:

verax init --local ~/.verax

verax serve --env-file ~/.verax/verax.env

claude mcp add --transport http verax http://127.0.0.1:8787/mcp --header "Authorization: Bearer $(cat ~/.verax/local-issuer/agent.token)"

The token can read and write memory through the gate; it cannot approve. The shipped policy refuses spend until you add a rule for it; a call your policy holds waits for verax approve on this machine, or for an approval through the operator door when one is set up. See docs/THREAT_MODEL.md.

With Conarium

@verax-ai/body 0.2.2 and later accepts --with-conarium. 0.2.1 does not carry the flag. The flag has npx download @conarium-ai/core from npm and run it as a child process; that needs a network.

Conarium masks the rows, and its sample policy denies its public.secrets table. Verax puts each call through the same gate as its own tools, keeps a signed record and a hash of the answer, and refuses a downstream tool the policy does not name before the child sees the call. When Conarium answers with an error, the body tells the caller that it did, not what it said.

What it prints, without a terminal to answer the approval question:

verax demo

memory.put / memory.get allowed; two signed records

message.send -> ops@blocked.test refused egress-blocked (signed) ref 6c6e4925-b769-4a8b-8fc4-e2443613a5b6

spend 100 minor USD sample-merchant held no terminal to ask, so it stays held (run this in a terminal to be asked)

conarium.query customers allowed; masked by Conarium before the rows left it measured [MASKED_PII] on every email and card

conarium.query public.secrets allowed by this gate; Conarium answered with an error and no rows recorded as a failed call

conarium.list_tables refused no-rule (signed) refused by this gate; the downstream server never saw the call

audit.explain of the refuse finding none trust-root own-key chain and signatures read back

records 8 effects 5 ledger removed on exit (run with --keep to keep it and check it with verax verify)

Not shown here: a real database (these are Conarium's sample rows); statement reconciliation needs a real statement (verax reconcile).

What ships

The three packages are published together and carry the same version; the capability matrix in docs/STATUS.md names the current one, and it is the version on npm. The body is also listed in the MCP registry as io.github.verax-ai/verax. What that version carries, what it does not, and the test holding each row up are in the capability matrix at the top of docs/STATUS.md.

Read the ledger back without us

A ledger only the vendor's running service can read is evidence a buyer rents, not evidence they hold. verax verify reads a state directory on its own — no body listening, nothing on the network — and states each check on its own line, because they fail separately. On a copy of the ledger `npx @verax-ai