MCP tools

The hosted server is at https://harness.chance.cc/api/mcp. It speaks Streamable HTTP over POST only, keeps no session, and answers with JSON. The local stdio package forwards every message to this server, so the tools below are the same in both. Setup: Local MCP and Connectors. Credentials. An API key (x-api-key or Authorization: Bearer) reaches every tool. An OAuth token reaches what its scope allows: mcp covers the verification and account tools and strk20_relay_status; wallet adds every other tool. Without the wallet scope, a wallet tool returns an error asking you to reconnect and approve wallet access. A request with no valid credential gets 401 with a WWW-Authenticate header pointing at /.well-known/oauth-protected-resource. Availability. The wallet, proposal, status and STRK20 tools exist only when the deployment has escrow wallets configured. check_connection reports escrowTools: true when this credential can use them. Results. Each tool returns text. Most end with a fenced JSON block holding the same data. A failure is a result with isError: true, not a protocol error. A wallet parameter accepts the wallet’s id or its name.

Verification

verify_intent

Checks an action against an intent and returns a verdict with its receipt. One credit, refunded if the run fails. Annotations: readOnlyHint: false, destructiveHint: false.

Parameter	Type
`intent`	string	Required. The rules.
`action`	string or object	Required. The action, or the exact payload.
`context`	object	Optional. Facts for the judge. `reference: {source, excerpt}` carries third-party documentation.
`venue`	enum	Optional. `hyperliquid`, `limitless`, `polymarket`, `dimes`, `myriad`, `orderly`, `derive`, `lifi`, `meow`, `liquid`, `robinhood`, `x402`, `agentcards`, `uniswap`, `solana`, `starknet`, `alchemy`, or `evm` (alias for `alchemy`).

Returns the verdict, reasoning, a proof summary, the verification id and the balance, then JSON: id, requestHash, status, verdict, reasoning, mode, venue, actionFamily, proof, creditsRemaining. Field details: Verification request.

get_verification

Fetches a past verification by id (UUID or requestHash). Free. Annotations: readOnlyHint: true. Returns id, requestHash, status, verdict, reasoning, createdAt and proof with anchorStatus, transcriptUri and explorerTx.

Account

check_connection

Confirms the credential works, without spending a credit. No parameters. Free. Annotations: readOnlyHint: true, idempotentHint: true. Returns ok, account (email, else wallet address, else account id), creditsRemaining, escrowTools and authMethod (api_key or oauth).

topup_credits

Buys credits with USDC on Base over x402. Costs no credits. Annotations: readOnlyHint: false, destructiveHint: false.

Parameter	Type
`credits`	integer	Required. 20 to 10,000.

Called without a payment, it returns isError: true with the x402 terms (in the text, in structuredContent and in _meta["x402/payment-required"]), the HTTP endpoint and the guide URL. Called again with a signed x402 v2 PaymentPayload in _meta["x402/payment"], it settles the payment, credits this account and returns the settlement in _meta["x402/payment-response"]. See Credits.

Wallets

These tools need the wallet scope and are free.

create_escrow_wallet

Annotations: readOnlyHint: false, destructiveHint: false.

Parameter	Type
`name`	string	Required. Unique on the account.
`chain`	`base` \| `solana` \| `starknet`	Required. Permanent.
`mode`	`autonomous` \| `safe`	Required. Permanent. Safe mode supports Base and Starknet.
`mandate`	string	Required. The rules the judge checks each proposal against.
`limits`	object	Optional. `maxPerTxUsd`, `dailyCapUsd` (rolling 24 hours), `tokenAllowlist` (token contract addresses; a well-known symbol resolves to its one real address on the chain, any other symbol permits nothing), `recipientAllowlist`.

Returns the address to fund, what the wallet needs for gas on its chain, and JSON: id, name, chain, mode, address, mandate, limits.

update_escrow_wallet

Changes a wallet’s name, mandate or limits. Mode and chain cannot change. Annotations: readOnlyHint: false, destructiveHint: false, idempotentHint: true.

Parameter	Type
`wallet`	string	Required.
`name`	string	Optional.
`mandate`	string	Optional.
`limits`	object	Optional. Same fields as on create. Sent to the custodian as well as saved.

At least one of name, mandate or limits is required. A change that loosens the rules is applied, not refused, and the reply says what it loosened. Returns JSON: wallet, name, mode, mandate, limits.

list_escrow_wallets

No parameters. Archived wallets are left out. Annotations: readOnlyHint: true. Returns one entry per wallet: id, name, chain, mode, address, mandate, balanceUsd, tokenCount, provider, custody, rules and explorerAddressUrl. rules.limits holds only the limits that are set. rules.enforcement says, per limit, who refuses a violation: signer (the custodian), chance (Chance’s check before signing) or judge (only the judge weighs it).

get_escrow_balances

Parameter	Type
`wallet`	string	Required.

Annotations: readOnlyHint: true. Returns walletId, name, address, balanceUsd and balances. Each balance has amount in base units and amountFormatted in whole units; the proposal tools take whole units.

list_swap_tokens

Parameter	Type
`chain`	`ethereum` \| `base`	Required.

Annotations: readOnlyHint: true, idempotentHint: true. Returns ETH (address native) and the token contracts Chance has verified on that chain, each with symbol, name, address, decimals and logoUrl.

quote_escrow_swap

Prices a swap without proposing it. Nothing is simulated, judged, signed or recorded, and the quote is not held. Annotations: readOnlyHint: true. Takes the same parameters as escrow_swap except note. Returns walletId, name, chain, slippageBps and swap (amounts in, out and minimum, price impact, estimated gas, and whether an approval is needed).

Proposals

These tools need the wallet scope. Each one simulates the action, checks the wallet’s limits, and runs the judge against the wallet’s mandate. One credit when the judge runs; a proposal the limits block first is free. Annotations: readOnlyHint: false, destructiveHint: true. Each returns the verdict, the reasoning, a one-line simulation summary, and then one of: the explorer link (executed), an approval link to send to the owner (held, with its expiry), or “not executed”. Then a proof summary, the transaction id, the balance, and JSON with the full proposal result: txId, status, verdict, reasoning, requestHash, simulation, approvalUrl, txHash, scanId, creditsRemaining, proof. An approval link means the funds have not moved. Field details: Escrow wallets API. note on every proposal tool is context for the judge. It is treated as untrusted narration that cannot grant permission, and it is cut at 2,000 characters. A call that times out on the client still creates the proposal on the server. Find it with list_escrow_transactions.

escrow_transfer

Sends a named asset as-is. On Solana it always waits for the owner.

Parameter	Type
`wallet`	string	Required.
`asset`	string	Required. Symbol, for example `USDC`. On Starknet: STRK, ETH, USDC or USDT.
`amount`	string	Required. Whole units, for example `"500"`.
`to`	string	Required. Recipient address.
`chain`	`ethereum` \| `base` \| `solana` \| `starknet`	Required. Must be the wallet’s chain.
`note`	string	Optional.

escrow_swap

Quotes on the Uniswap Trading API, builds the batch (an approval for exactly the sell amount when needed, then the swap) and proposes it. Base and Ethereum wallets only. The JSON also carries swap.

Parameter	Type
`wallet`	string	Required.
`sell`	string	Required. A 0x address, `ETH`, `WETH`, `USDC`, or a symbol the wallet holds.
`buy`	string	Required. A 0x address, `ETH`, `WETH` or `USDC`.
`amount`	string	Required. Amount to sell, in the sell token’s units.
`chain`	`ethereum` \| `base`	Required. Must be the wallet’s chain.
`slippageBps`	integer	Optional. 1 to 1,000, default 50. Sets the minimum output in the signed swap.
`note`	string	Optional.

escrow_execute

Proposes a raw transaction. Send exactly one of transaction, calls, solanaTransaction or starknetCalls.

Parameter	Type
`wallet`	string	Required.
`chain`	`ethereum` \| `base` \| `solana` \| `starknet`	Required. Must be the wallet’s chain.
`transaction`	object	One EVM transaction, `{to, value, data}`.
`calls`	object[]	An EVM batch of `{to, value, data}`.
`solanaTransaction`	string	A base64 Solana transaction.
`starknetCalls`	object[]	A Starknet multicall of `{contractAddress, entrypoint, calldata}`, executed as one transaction.
`starknetProof`	object	Optional. `{facts, data}`, required only for a call to the privacy pool’s `apply_actions`. Not stored.
`note`	string	Optional.

escrow_pay_x402

Pays for an HTTP resource that charges with x402, and returns what the resource sends back. Chance requests the URL itself, reads the terms from the 402 response, and puts the exact amount, token and recipient through the gate. EVM wallets only. A self-custodial safe wallet cannot pay this way.

Parameter	Type
`wallet`	string	Required.
`url`	string	Required. The final URL. Redirects and private or loopback hosts are refused. The resource must answer 402 with x402 v2 terms in its JSON body.
`method`	`GET` \| `POST`	Optional. Default `GET`.
`maxAmount`	string	Optional. Refuse if the invoice is above this, in whole tokens.
`note`	string	Optional.

When the payment executes, the reply includes up to 8,000 characters of the resource’s response.

Status

These tools need the wallet scope, are free, and are read-only.

list_escrow_transactions

Parameter	Type
`wallet`	string	Optional. One wallet only.
`status`	enum	Optional. `verifying`, `awaiting_user`, `executing`, `executed`, `failed`, `blocked` or `expired`.
`limit`	integer	Optional. 1 to 50, default 20.

Newest first. Each entry: id, walletId, status, verdict, summary, explorerUrl, approvalUrl (while awaiting the owner), error, createdAt.

get_escrow_transaction

Parameter	Type
`id`	string	Required. The `txId` from a proposal.

Returns id, walletId, status, verdict, txHash, explorerUrl, approvalUrl (while awaiting the owner), error, createdAt, updatedAt. An approval past its window reads expired.

STRK20 private actions

Starknet wallets only. All free.

strk20_sign_proof_invocation followed by strk20_relay_private_action puts a private action on chain without a proposal: no simulation, no limit check and no verdict. The gated route is escrow_execute with starknetCalls and starknetProof. Until the sign-and-relay path is gated, treat it as ungated.

strk20_relay_status

Whether private actions can be relayed through AVNU’s paymaster: key configured, relay reachable, key accepted. No parameters. Does not need the wallet scope. Annotations: readOnlyHint: true.

strk20_pool_fee

What the relayer charges, as a withdraw action to add to the action set before proving. Annotations: readOnlyHint: true.

Parameter	Type
`feeToken`	string	Optional. Token address. Default STRK.

strk20_sign_proof_invocation

Signs a private action with the wallet’s key and proves it. The signature authorizes the action. Annotations: readOnlyHint: false, destructiveHint: true.

Parameter	Type
`wallet`	string	Required. A Starknet wallet.
`compileActionsCalldata`	string[]	Required. Felts for `compile_actions(user_addr, user_private_key, client_actions)`. The first must be the wallet’s address.

Returns wallet, address, pool, calldata, signature and proof. The proof expires in about five minutes.

strk20_viewing_key_signature

Signs the fixed viewing-key derivation message for the wallet. The client derives the viewing key from it, which decrypts the wallet’s shielded notes. No caller-supplied bytes are signed. Annotations: readOnlyHint: false, destructiveHint: false.

Parameter	Type
`wallet`	string	Required. A Starknet wallet.

Returns wallet, address, signature.

strk20_relay_private_action

Relays a proven apply_actions call through the paymaster. The wallet pays no STRK for gas. Annotations: readOnlyHint: false, destructiveHint: true.

Parameter	Type
`call`	object	Required. `{contractAddress, entrypoint, calldata}` from the prover.
`proof`	string	Required. Base64 proof.
`proofFacts`	string[]	Required. Hex felts.
`feeToken`	string	Optional. Must match the token the fee was quoted in.

Returns txHash and trackingId.

Overview

Endpoints

Verification

verify_intent

get_verification

Account

check_connection

topup_credits

Wallets

create_escrow_wallet

update_escrow_wallet

list_escrow_wallets

get_escrow_balances

list_swap_tokens

quote_escrow_swap

Proposals

escrow_transfer

escrow_swap

escrow_execute

escrow_pay_x402

Status

list_escrow_transactions

get_escrow_transaction

STRK20 private actions

strk20_relay_status

strk20_pool_fee

strk20_sign_proof_invocation

strk20_viewing_key_signature

strk20_relay_private_action

​Verification

​verify_intent

​get_verification

​Account

​check_connection

​topup_credits

​Wallets

​create_escrow_wallet

​update_escrow_wallet

​list_escrow_wallets

​get_escrow_balances

​list_swap_tokens

​quote_escrow_swap

​Proposals

​escrow_transfer

​escrow_swap

​escrow_execute

​escrow_pay_x402

​Status

​list_escrow_transactions

​get_escrow_transaction

​STRK20 private actions

​strk20_relay_status

​strk20_pool_fee

​strk20_sign_proof_invocation

​strk20_viewing_key_signature

​strk20_relay_private_action

Verification

verify_intent

get_verification

Account

check_connection

topup_credits

Wallets

create_escrow_wallet

update_escrow_wallet

list_escrow_wallets

get_escrow_balances

list_swap_tokens

quote_escrow_swap

Proposals

escrow_transfer

escrow_swap

escrow_execute

escrow_pay_x402

Status

list_escrow_transactions

get_escrow_transaction

STRK20 private actions

strk20_relay_status

strk20_pool_fee

strk20_sign_proof_invocation

strk20_viewing_key_signature

strk20_relay_private_action