# Fabric Verify [Health: Active]

**Category:** 🔑 Cryptography  
**Repository:** https://github.com/AugmentEVzero/fabric-verify-mcp  
**GitHub Stars:** 0  
**npm Downloads (last month):** 950  
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**Installs:** 0  
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**Directory Page:** https://allmcps.com/mcp/fabric-verify-2

## Description
Signed, publicly logged records of what your AI agent did, with proofs anyone can check offline.

## Tools
Capabilities this server exposes over MCP:

- **record_action**
- **kind**
- **summary**
- **idempotency_key**
- **approval_record**
- **record_event**
- **event**
- **body**
- **action**
- **run_id**
- **step_id**
- **parent_record**
- **delegation_record**
- **record**
- **body.approval_record**
- **other**
- **export_events**
- **indices**
- **get_proof**
- **index**
- **wait_seconds**
- **check_balance**
- **buy_credit_link**
- **amount_usd**

## Claude Desktop Quick Installation
Install path detected from listing signals. Uses `npx` (confidence: high):

```json
"mcpServers": {
  "fabric-verify": {
    "command": "npx",
    "args": ["-y","@augmentev/fabric-verify-mcp"],
    "env": {
      "FABRIC_CREDIT_KEY": ""
    }
  }
}
```

**Requires environment variables:** `FABRIC_CREDIT_KEY` — the values above are empty placeholders; fill in real credentials before running (see the repository for what each one is for).

## Documentation

## What Fabric Verify does

Fabric Verify creates tamper-evident records for agent activity and submits them to the Fabric Verify public log. The local package signs each record with a key held on the machine, then returns a log index that can be used to retrieve a proof later.

The service preserves record text locally. The public log receives a salted fingerprint, the action kind, a timestamp, and coded identifiers that can be linked to an agent by the agent owner or an auditor with an audit pack. Records are permanent. Agent names, key names, and public keys are kept in an erasable store, so personal information should not be placed in `FABRIC_AGENT` or `FABRIC_KID`.

A proof establishes that one exact record was logged without alteration by a particular time. It does not establish that the event described by the record actually happened or that a reported tool result is true.

## How it works

The package runs as a local stdio MCP process. `record_action` signs and submits a concise action record; `record_event` handles structured events such as tool calls, results, approvals, delegations, policy decisions, and halts. Events can refer to earlier records through returned record identifiers and fields such as `run_id`, `step_id`, `parent_record`, and `delegation_record`.

Record text, salts, keys, and fetched proofs are stored beneath `FABRIC_HOME`, which defaults to `~/.fabric-verify`. If a recording call fails, repeating it with the same idempotency key, kind, and summary resends the same signed record and avoids charging it more than once.

`get_proof` retrieves a proof, optionally waiting up to 45 seconds. Proofs are commonly available a few minutes after recording. `export_events` collects selected events and their proofs into a file for offline checking with the `augmentev-verify` utility.

## Setup and configuration

Node.js 20 or later is required. Configure an MCP client to run `npx -y @augmentev/fabric-verify-mcp`, and provide a prepaid `FABRIC_CREDIT_KEY` plus a stable, printable-ASCII `FABRIC_AGENT` value. Claude Code can add the server with `claude mcp add` and equivalent environment options.

Optional settings select the signing-key name, local storage directory, and per-session spending ceiling:

- `FABRIC_KID` defaults to `<agent>-key-1`; change it when rotating keys.
- `FABRIC_HOME` defaults to `~/.fabric-verify`.
- `FABRIC_MAX_SPEND_USD` defaults to `1`.

Back up `FABRIC_HOME/agent-ed25519.pem`. If that key is lost, use a new `FABRIC_KID`.

The remote connector at `https://mcp.augmentev.com/mcp` requires no local package installation. A sign-in flow accepts the credit key, assistant name, and daily limit, then gives the client an access token. Remote records use an AugmentEV-hosted signing key rather than a key held by the agent.

## Tools and capabilities

- `record_action` logs a signed action with a kind, summary, optional idempotency key, and optional approval record. Each record costs $0.005 from prepaid credit.
- `record_event` logs structured agent events at the same price and supports links between related actions, approvals, delegations, runs, and steps.
- `export_events` creates a proof-bearing event bundle and is free.
- `get_proof` fetches and stores an individual proof at no cost.
- `check_balance` reports remaining credit and spending for the session.
- `buy_credit_link` creates a card checkout link for $25, $50, $100, or $500 without charging through the tool.

Download the verifier and published log keys from `augmentev.com/verify`, then run `augmentev-verify log-proof proof.json --pins fabric-log-v1.json --audit agent-record.json` in the record directory.

## Limitations and notes

The local package requires prepaid credit for recording calls. The remote connector exposes only `record_action`, `record_event`, `get_proof`, and `check_balance`, and its records are labelled `augmentev-hosted`.

An exported bundle proves that included events were logged unchanged and that links point to earlier events of the expected type. It does not prove that the bundle contains every event, nor that a described tool result is correct. Events created on different machines must be merged in log order for combined checking.

For production use, pin an exact package version and update it deliberately. Keep the agent key available for future verification and audit work.

_Full upstream README: https://allmcps.com/mcp/fabric-verify-2/readme_