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Cleave for Agents: token swaps, cross-chain swaps and gas top-ups

fi.cleave/swapcleave.fistreamable-httpv1.0.0Scanned

Swap, bridge and get gas on 6 EVM chains. Each plan states its outcome before you sign. No API key.

4 tools: 1 do something that can't be undone, 2 change things and 1 only read.

Tools: 0 delete, 1 irreversible, 2 write, 1 read.
  • Reads private data · 0
  • Reads text others write · 4
  • Can send data out · 2
  • 2 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.

4 tools

Can't be undone 1Claude Code: ask
  • cleave_plan_swapPlans a token swap on one chain, a cross-chain swap or bridge, or a native-gas top-up on Ethereum, Arbitrum, Base, BNB Chain, Polygon or Optimism, and returns unsigned transactions…Reads text others writeCan send data out1 finding

    Why it is in this group

    • The input addresses people (input.recipient): what it sends cannot be taken back.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.

    What it can reach

    • untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
    • outboundThe input takes a destination (input.recipient): what the tool writes goes there.

    Findings

    • Warn

      The server marks "cleave_plan_swap" read-only (readOnlyHint: true), and its own name, description or input give the class "irreversible".

      Matched text

      annotations: {"readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":true}; The input addresses people (input.recipient): what it sends cannot be taken back.

      What this check looks for
    Description, as the server wrote it
    Plans a token swap on one chain, a cross-chain swap or bridge, or a native-gas top-up on Ethereum, Arbitrum, Base, BNB Chain, Polygon or Optimism, and returns unsigned transactions for the given wallet to sign. It fits when the user wants to exchange tokens, move them between these chains, or get ETH, BNB or POL for gas. It sends nothing and moves no funds. The answer leads with blocking notices and warnings, then gives the route's outcome kind (exact or at least a minimum; with a swap on arrival, the token, else a named fallback; where a transfer can go unfilled, a refund of the bridged token on the source chain hours later), every third-party cost except network gas, the expected time, validUntil and the calls in signing order. A blocking notice returns no calls; a warning, or a recipient other than the wallet, sets requiresConfirmation, and the connection's settings can turn either into a refusal. Calls sent after validUntil are stale: they can revert or, on some routes, end in a refund hours later. Amounts are decimal strings in token units; tokens are listed symbols or contract addresses; the recipient defaults to the wallet. Limits set in the connection (a pinned wallet, a per-plan USD cap, listed tokens only) bound every argument. For an ambiguous symbol, cleave_find_token lists the candidates; after sending, cleave_track_swap reports progress. A wallet with no gas can get it with cleave_get_gas.

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
Changes things 2Claude Code: ask
  • cleave_get_gasGets native gas (ETH, BNB or POL) on Ethereum, Arbitrum, Base, BNB Chain, Polygon or Optimism for a wallet that holds USDC on Ethereum, Arbitrum, Base, Optimism or Polygon but has …Reads text others writeCan send data out1 finding

    Why it is in this group

    • The name "cleave_get_gas" says "get": a word for reading.
    • The server marks it as not read-only (readOnlyHint: false).

    What it can reach

    • untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
    • outboundThe input takes a destination (input.recipient): what the tool writes goes there.

    Findings

    • Warn

      The server marks "cleave_get_gas" as not read-only (readOnlyHint: false), and its words say it reads.

      Matched text

      annotations: {"readOnlyHint":false,"destructiveHint":false,"idempotentHint":true,"openWorldHint":true}; The name "cleave_get_gas" says "get": a word for reading.

      What this check looks for
    Description, as the server wrote it
    Gets native gas (ETH, BNB or POL) on Ethereum, Arbitrum, Base, BNB Chain, Polygon or Optimism for a wallet that holds USDC on Ethereum, Arbitrum, Base, Optimism or Polygon but has no gas to send transactions. Called with the paying chain, the receiving chain, the recipient and a USDC amount, it returns an offer: the fee, the minimum native amount, the deadline, the order and one USDC authorization for the wallet to sign; signing costs no gas. Called again with the offer and the signature, it passes the signed order to Cleave's relayer, which executes it through a contract made for that one order, and returns a requestId for cleave_track_swap. On one chain the recipient gets at least the minimum or nothing moves; from another chain it gets the native coin at the minimum, else USDC on arrival if the arrival swap fails. An order not executed by its deadline is refunded to the refund address, or, if paid from another chain and not filled, refunded hours later. When the wallet already holds some gas, cleave_plan_swap plans a swap to the native coin.

    Annotations the server declares

    • readOnlyHint: false
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
  • cleave_track_swapReports the status of a swap, bridge or gas top-up that was planned with cleave_plan_swap and then sent, or ordered with cleave_get_gas: its state (for example pending, in flight, …Reads text others writeNo findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.

    What it can reach

    • untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
    Description, as the server wrote it
    Reports the status of a swap, bridge or gas top-up that was planned with cleave_plan_swap and then sent, or ordered with cleave_get_gas: its state (for example pending, in flight, delivered, refund pending or refunded), what arrived against the plan and on which chain, and the next action or when to check again. It takes the chain and transaction hash, plus the plan's requestId when known, or for a gas top-up the requestId alone; a transaction to a contract outside Cleave's published list is reported as such. It fits when the user asks whether such a transfer arrived, and before any re-send, because re-sending a plan that is still in flight can pay twice. It reports states only and returns no transactions.

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
Only reads 1Show 1 read-only tool
  • cleave_find_tokenFinds a token by symbol or contract address on Ethereum, Arbitrum, Base, BNB Chain, Polygon or Optimism and returns its address, decimals and whether it is on Cleave's token list, …Reads text others writeNo findings

    Why it is in this group

    • The name "cleave_find_token" says "find": a word for reading.

    What it can reach

    • untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
    Description, as the server wrote it
    Finds a token by symbol or contract address on Ethereum, Arbitrum, Base, BNB Chain, Polygon or Optimism and returns its address, decimals and whether it is on Cleave's token list, with a flag when it resembles a listed token. A symbol shared by several listed tokens returns every candidate by address instead of picking one. An unlisted token is found only by its address and comes back flagged, without a name or symbol. It fits before cleave_plan_swap when the user names a token by symbol and the address is unknown.

    Annotations the server declares

    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true

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.

Reads private data0
Reads files, mail, messages, databases, secrets, calendars or repositories.
Reads text others write4
Brings in text someone else can write: web pages, inbound email, messages, issues and comments.
Can send data out2
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.

2 warn
  • The server marks "cleave_plan_swap" read-only (readOnlyHint: true), and its own name, description or input give the class "irreversible".

    Matched text

    annotations: {"readOnlyHint":true,"destructiveHint":false,"idempotentHint":true,"openWorldHint":true}; The input addresses people (input.recipient): what it sends cannot be taken back.

    What this check looks for
  • The server marks "cleave_get_gas" as not read-only (readOnlyHint: false), and its words say it reads.

    Matched text

    annotations: {"readOnlyHint":false,"destructiveHint":false,"idempotentHint":true,"openWorldHint":true}; The name "cleave_get_gas" says "get": a word for reading.

    What this check looks for

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 1.0.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http swap https://api.cleave.fi/mcp
claude mcp add --transport http swap https://api.cleave.fi/mcp

Run 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.

.claude/settings.json
{
  "permissions": {
    "allow": [
      "mcp__swap__cleave_find_token"
    ],
    "ask": [
      "mcp__swap__cleave_plan_swap",
      "mcp__swap__cleave_track_swap",
      "mcp__swap__cleave_get_gas"
    ],
    "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 swap. Review it before you use it.

Capability tags behind 4 rules
  • mcp__swap__cleave_plan_swap untrusted-input, outbound
  • mcp__swap__cleave_track_swap untrusted-input
  • mcp__swap__cleave_find_token untrusted-input
  • mcp__swap__cleave_get_gas untrusted-input, 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/fi.cleave/swap/verify?hash=203c0eb17da9a3a8c3725a23c62b8e079e35f355d7cdb7cff27aa7ae9e94c76a" | jq -e '.changed == false'

Pinned hash 203c0eb17da9, from Oct 26, 2026, 13:17 UTC.

Watch

Get told when its tools change: a new tool, a new description, a new class.

https://anlyon.dev/servers/fi.cleave/swap/changes.xml

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Badge

anlyon.dev badge for fi.cleave/swap
[![anlyon.dev](https://anlyon.dev/badge/fi.cleave/swap.svg)](https://anlyon.dev/servers/fi.cleave/swap)

Source: MCP Registry. Synced Oct 26, 2026, 13:17 UTC.