spendctl
dev.spendctl/spendctlspendctl.devstreamable-httpv0.1.0Scanned
Spend policy for AI agents that pay (x402, MPP). Login-free sandbox, real sidecar, no real funds.
6 tools: 1 do something that can't be undone, 2 change things and 3 only read.
- Reads private data · 0
- Reads text others write · 0
- Can send data out · 1
- No findings
Anlyon alternative
3 of these tools change something. Run those as governed actions.
Declare what an action changes, and Anlyon puts it under a shared limit, binds every approval to the exact request, and grades the outcome. It works on any HTTPS API you can describe as an action.
Anlyon does not run, proxy or govern this MCP server. A tool your own code calls directly is not routed through Anlyon and is not governed by it.
Import an OpenAPI spec →Tools
Grouped by what each tool does, most consequential first. Open one for its reasons and full description; descriptions are the publisher's own words.
6 tools
Can't be undone 1Claude Code: ask
sandbox_payFetches one of the sandbox's paid endpoints (HTTP 402, x402) through the spendctl sidecar: https://weather.sandbox.spendctl.dev/weather?city=<name> ($0.01) or https://search.sandbo…Can send data outNo findings
Why it is in this group
- The name "sandbox_pay" says "pay": a word that usually means money moves, which cannot be taken back.
What it can reach
- outboundThe input takes a URL (input.url): a request to a URL can carry data to whoever runs it.
Description, as the server wrote it Fetches one of the sandbox's paid endpoints (HTTP 402, x402) through the spendctl sidecar: https://weather.sandbox.spendctl.dev/weather?city=<name> ($0.01) or https://search.sandbox.spendctl.dev/search?q=<query> ($0.02), as listed by sandbox_create and documented at https://spendctl.dev/docs/sandbox/. The sidecar applies the sandbox agent's budget, allowlist and approval policy, pays with the throwaway wallet if allowed, and returns the response. A refusal or a pending approval is explained in the result. Only sandbox hosts exist; no real funds are involved.
Annotations the server declares
- readOnlyHint: false
- destructiveHint: false
- idempotentHint: false
- openWorldHint: false
Changes things 2Claude Code: ask
approveDecides a pending approval in this sandbox, as the human approver would with `spendctl approve`.No findings
Why it is in this group
- The name "approve" says "approve": a word for a change.
Description, as the server wrote it Decides a pending approval in this sandbox, as the human approver would with `spendctl approve`. An approved payment completes when sandbox_pay is called again with the same approvalId; a denied one stays refused.
Annotations the server declares
- readOnlyHint: false
- destructiveHint: false
- idempotentHint: true
- openWorldHint: false
sandbox_createCreates an isolated spendctl sandbox: a real spendctl sidecar with a throwaway wallet, mock paid APIs and a mock facilitator.No findings
Why it is in this group
- The name "sandbox_create" says "create": a word for a change.
Description, as the server wrote it Creates an isolated spendctl sandbox: a real spendctl sidecar with a throwaway wallet, mock paid APIs and a mock facilitator. No real money moves and nothing outside the sandbox is reachable. Returns the sandbox_id to pass to the other tools, the agent's spending policy and the paid endpoints that exist.
Annotations the server declares
- readOnlyHint: false
- destructiveHint: false
- idempotentHint: false
- openWorldHint: false
Only reads 3Show 3 read-only tools
check_budgetShows the sandbox agent's spending limits, what has been spent in each window, and what is left.No findings
Why it is in this group
- The description's first verb is "show": a word for reading.
Description, as the server wrote it Shows the sandbox agent's spending limits, what has been spent in each window, and what is left.
Annotations the server declares
- readOnlyHint: true
- openWorldHint: false
get_policyReturns the sandbox's spendctl.yaml: the agent's budgets, allowed hosts and approval rules.No findings
Why it is in this group
- The name "get_policy" says "get": a word for reading.
Description, as the server wrote it Returns the sandbox's spendctl.yaml: the agent's budgets, allowed hosts and approval rules.
Annotations the server declares
- readOnlyHint: true
- openWorldHint: false
list_receiptsLists the sandbox agent's recent payment attempts (paid, refused, waiting for approval) with amounts, reasons and mock transaction hashes.No findings
Why it is in this group
- The name "list_receipts" says "list": a word for reading.
Description, as the server wrote it Lists the sandbox agent's recent payment attempts (paid, refused, waiting for approval) with amounts, reasons and mock transaction hashes.
Annotations the server declares
- readOnlyHint: true
- openWorldHint: false
This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.
Exfil surface
Which tools read private data, which read text someone else can write, and which can send data out. One of each is a path a prompt injection can use.
No private-data, untrusted-input, outbound path in this server alone: no tool is tagged private-data or untrusted-input.
- Reads private data0
- Reads files, mail, messages, databases, secrets, calendars or repositories.
- Reads text others write0
- Brings in text someone else can write: web pages, inbound email, messages, issues and comments.
- Can send data out1
- Can carry data to people or systems: it sends, posts or publishes, or takes a recipient, channel or URL.
Other servers in the same agent add their own tools to these paths. Audit your whole setup to see them together.
Findings
Matches of fixed checks, with the text they matched.
No check matched anything in these tool definitions. That is not a safety guarantee.
History
Changes to its tool definitions and to its remote endpoint, newest first.
No change seen yet. Its tools are rescanned every day, and a remote endpoint is looked at once a week.
Install
Pinned to version 0.1.0. Values in angle brackets are yours to fill in.
claude mcp add --transport http spendctl https://mcp.spendctl.dev/mcpclaude mcp add --transport http spendctl https://mcp.spendctl.dev/mcpRun in a terminal.
Claude Code permissions
Allow the reads, ask before a change or a way out, deny the deletes. Paste into .claude/settings.json.
{
"permissions": {
"allow": [
"mcp__spendctl__check_budget",
"mcp__spendctl__list_receipts",
"mcp__spendctl__get_policy"
],
"ask": [
"mcp__spendctl__sandbox_create",
"mcp__spendctl__sandbox_pay",
"mcp__spendctl__approve"
],
"deny": []
}
}Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. A read that can send data out (it takes a URL, say) asks first too. It assumes the server is installed as spendctl. Review it before you use it.
Capability tags behind 1 rule
- mcp__spendctl__sandbox_pay outbound
Pin
Keep the decision: fail CI when the tools change, follow every change, or show a badge.
Pin in CI
Fail a build when the tools you reviewed are not the tools the server serves today.
curl -s "https://anlyon.dev/api/v1/servers/dev.spendctl/spendctl/verify?hash=469ab8ae783df0b7c0c595a9aac76aa37320286ea728771570370bb969685f15" | jq -e '.changed == false'Pinned hash 469ab8ae783d, from Oct 26, 2026, 09:18 UTC.
Watch
Get told when its tools change: a new tool, a new description, a new class.
https://anlyon.dev/servers/dev.spendctl/spendctl/changes.xmlAn Atom feed. Works in any feed reader or Slack's RSS app.
Badge
[](https://anlyon.dev/servers/dev.spendctl/spendctl)Source: MCP Registry. Synced Oct 26, 2026, 09:17 UTC.