MCP server: One MCP server.

AgentGuard

@merchantguardRun by its publisher: served from their own domain, namespace checked by the registry.MCP server · External

Local spend caps, kill-switch blocking and Ed25519-signed receipts for AI agent tool calls.

AI agent governancev0.3.1JavaScript
Freeno charge per call

Runs on your machine from its package; the steps are below.

What it does

  1. Reads
  2. Writes
  3. High impact

At most: creates or changes data: records, files, settings.

What it costs

Free

Odel charges nothing per call. The publisher may charge for its own service.

Runs locally over stdio

This server isn't hosted — your MCP client launches it from a package registry. Use one of the commands below, or drop the config into your client (e.g. Claude Desktop).

npm@agentguard-run/mcpv0.3.1

Run

npx -y @agentguard-run/mcp

MCP client config

{
  "mcpServers": {
    "agentguard": {
      "command": "npx",
      "args": [
        "-y",
        "@agentguard-run/mcp"
      ]
    }
  }
}
README3 min read

@agentguard-run/mcp

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AgentGuard® as an MCP server: local spend caps and Ed25519-signed provenance receipts for AI agent actions, usable from any Model Context Protocol host (Claude Desktop, Claude Code, Cursor, Cline, or your own agent runtime).

Zero data plane. Tools accept metadata only: model names, token counts, endpoint URLs. Prompts and completions never pass through this server, and their content stays on your machine. Receipts are content-free.

A configured license uses the license and seat service. Optional activation telemetry requires consent and can be disabled with AGENTGUARD_NO_BEACON=1. Neither path sends prompts, tool content or receipts.

Install

json
{
  "mcpServers": {
    "agentguard": {
      "command": "npx",
      "args": ["-y", "@agentguard-run/mcp"]
    }
  }
}

Optional environment variables:

VariableDefaultMeaning
AGENTGUARD_MCP_DAILY_CAP_CENTS500Hard per-day spend cap (block on exceed)
AGENTGUARD_MCP_PER_CALL_CAP_CENTS100Hard per-call spend cap (block on exceed)
AGENTGUARD_MCP_TENANTmcp-localTenant scope stamped into receipts
AGENTGUARD_HOME~/.agentguardSigning key and decision-ledger directory
AGENTGUARD_MCP_LEDGERndjsonPersist signed decisions; memory restores process-only storage
AGENTGUARD_MCP_DISABLE_COST_OVERRIDEunset1 discards and prevents pricing overrides
AGENTGUARD_ACTOR_DIGESTunset1 stores SHA-256 digests of actor IDs; provider stays readable

A signing keypair is generated on first run and persisted to <AGENTGUARD_HOME>/mcp-signing.json (0600). Signed decisions are appended to <AGENTGUARD_HOME>/<tenant>/decisions.ndjson, including the public verification key. Exports include prior process runs and new decisions extend the existing chain. Tenant directory names use the spend store's filename normalization. Spend counters remain process-local, as in earlier versions.

All tools accept optional agent_id, task_id, and workflow_id identifier parameters. spend_decide passes these to the call context, signing them as actor.agentId, actor.taskId, and actor.workflowId; the configured tenant becomes actor.tenantId. Other tools accept these metadata fields without recording a spend decision. Prompts, arbitrary content, credentials, and filesystem paths are rejected as IDs. Existing calls without these parameters keep working.

Tools

  • spend_decide: gate a model call before it runs. Returns allow/block plus a signed, hash-chained receipt recording model identity, weights origin country (China-origin families such as GLM, DeepSeek, Qwen, and Kimi are flagged automatically), hosting jurisdiction, and retention posture. Unrecognized endpoints (vLLM, Ollama, TGI, your own cluster) route as self-hosted: zero retention, your jurisdiction.
  • verify_receipt: independently verify any receipt. Change one signed byte and verification fails.
  • export_receipts: export the tenant decision ledger as a verified hash chain, including earlier process runs. Memory mode exports only the current process.
  • set_model_cost: register pricing for self-hosted models (AgentGuard fails closed on unknown costs).
  • provenance_preview: see what would be attested for a model/endpoint without spending.
  • spend_status: active caps, tenant, decision count, signer fingerprint.

Why

When agents move from hosted APIs to self-hosted models, the provider's spend dashboard, rate limits, and audit logs disappear with the provider. AgentGuard puts them back, locally, and adds something hosted providers never gave you: a cryptographic receipt an outsider can verify without trusting you or us.

More: https://agentguard.run/sovereign/ and https://agentguard.run/sovereign/guide/

Verify independently

Any receipt can be checked off-platform at https://agentguard.run/verify or with verify_receipt and the signer public key from spend_status.

Local release verification

Requires Node.js 20.19 or later. Run npm ci, npm test, and npm run scan:release from this package or its public mirror. The lockfile uses the published spend 0.19.0 package; no private sibling checkout is required.

Release checklist: keep package.json, the server version in src/index.ts, and both versions in server.json aligned; run the tests and release scan; publish npm first, publish with mcp-publisher, then verify the registry's active entry. See the registry release guide for exact commands and the public mirror allowlist.

The official registry name is io.github.MerchantGuard/agentguard. Its package entry runs @agentguard-run/mcp locally through npx and stdio.

AgentGuard® is a registered trademark of Dunecrest Ventures Inc. US patent filings pending. This package is governance software, not legal or compliance advice.

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