CommerceGate MCP gives operations agents a narrow, tenant-bound way to evaluate proposed commerce actions and inspect their evidence. It is the operations-facing companion to the broader Decionis Protocol MCP: this package focuses only on order acceptance, price changes, signed Decision Dossiers, proof packets, and Shadow Mode reports.

The server is local STDIO. It calls the Decionis API for tenant operations but contains no marketplace client and exposes no order, price, refund, fulfillment, or inventory mutation tool.

Package: @decionis/commerce

Install

CommerceGate requires Node.js 20 or later. Start the pinned public package with:

npx -y @decionis/commerce@0.1.0

The process starts without credentials so an MCP client can discover its capabilities. Tenant evaluation and evidence tools require DECIONIS_API_KEY and DECIONIS_ORG_ID in the process environment. Store DECIONIS_API_KEY in the MCP client's secret or environment manager; never place it in command arguments, source control, prompts, or logs. DECIONIS_API_BASE is optional and defaults to https://api.decionis.com.

For a capability-only startup, omit both tenant variables and call commercegate_describe_capabilities. Every tenant call will fail closed until both required tenant values are available.

Codex client configuration

Forward the three named variables from the environment that launches Codex:

[mcp_servers.commercegate]
command = "npx"
args = ["-y", "@decionis/commerce@0.1.0"]
env_vars = ["DECIONIS_API_KEY", "DECIONIS_ORG_ID", "DECIONIS_API_BASE"]
enabled = true
required = false
startup_timeout_sec = 20
tool_timeout_sec = 45
default_tools_approval_mode = "writes"
enabled_tools = [
  "commercegate_describe_capabilities",
  "commercegate_evaluate_action",
  "commercegate_get_dossier",
  "commercegate_get_proof_packet",
  "commercegate_list_shadow_reports",
  "commercegate_summarize_shadow_reports",
]

Safety contract

commercegate_evaluate_action is hard-locked to SHADOW. It can create an evaluation and Decision Dossier, but it never executes the proposed action.
APPROVE is evidence, not user consent and not permission to mutate a marketplace.
REJECT means stop. REVIEW or ESCALATE means hold and involve an authorized human.
Tenant calls are bound to DECIONIS_ORG_ID; tools never accept an organization override.
The process starts without credentials so clients can inspect its capabilities. Every tenant call then fails closed with a redacted configuration error.
API credentials are never returned. Fail-closed errors omit configured organization values and upstream response bodies.

Tools

Tool	Purpose	External effect
`commercegate_describe_capabilities`	Inspect support, safety guarantees, and connection state	None; local only
`commercegate_evaluate_action`	Evaluate `ORDER_ACCEPTANCE` or `PRICE_CHANGE`	Writes only a Shadow Mode evaluation/evidence record
`commercegate_get_dossier`	Read a signed Decision Dossier by UUID	Tenant read
`commercegate_get_proof_packet`	Read a dossier proof packet by UUID	Tenant read
`commercegate_list_shadow_reports`	Read recent Shadow Mode evaluation reports	Tenant read
`commercegate_summarize_shadow_reports`	Read aggregate Shadow Mode outcomes and near misses	Tenant read

commercegate_evaluate_action accepts a discriminated action object. Order acceptance requires order_id, gross_amount, discount_amount, estimated_cost, and an ISO-4217 currency. Price changes require sku, nullable from_price, to_price, estimated_cost, and currency. Both require a stable actor, platform, and bounded idempotency_key. CommerceGate computes net revenue, net margin amount, and net margin fraction before sending the Shadow Mode evaluation.

The two Shadow Report tools accept an optional days window from 1–365 and limit from 1–100. Both read the canonical /v1/protocol/shadow-reports document; the list tool presents operational rows while the summary tool presents its aggregate view.

CommerceGate normalizes Protocol outcomes for operations agents:

Protocol outcome	CommerceGate disposition	Agent behavior
`APPROVE`	`PROCEED`	Preflight passed; proceed only when the user separately authorized execution.
`REJECT`	`BLOCK`	Stop.
`REVIEW`, `ESCALATE`	`HOLD`	Hold and route to an authorized human.
Missing or unknown	`HOLD`	Fail closed and ask an operator to inspect the dossier.

Configuration

Environment variable	Required	Secret	Meaning
`DECIONIS_API_KEY`	For tenant calls	Yes	Decionis organization API key
`DECIONIS_ORG_ID`	For tenant calls	No	UUID that permanently scopes this server process
`DECIONIS_API_BASE`	No	No	API origin; defaults to `https://api.decionis.com`

The API base must use HTTPS. HTTP is accepted only for loopback development.

Example action

{
  "action": {
    "action_type": "ORDER_ACCEPTANCE",
    "actor": { "type": "AGENT", "id": "order-ops-agent" },
    "platform": "walmart-marketplace",
    "idempotency_key": "order:123:acceptance:v1",
    "payload": {
      "order_id": "123",
      "gross_amount": 100,
      "discount_amount": 10,
      "estimated_cost": 60,
      "currency": "USD"
    }
  },
  "policy_version": "commerce-2026-09"
}

The response explicitly states that no downstream action was executed and tells the agent how to handle the returned outcome.

Develop from source

Run the repository checkout through the workspace command when developing an unreleased change:

pnpm --filter @decionis/commerce typecheck
pnpm --filter @decionis/commerce test
pnpm --filter @decionis/commerce build
pnpm --silent --filter @decionis/commerce mcp