Open Wallet

Use https://tx.steer.fun to have a user execute a wallet action (send a transaction or sign a message) with their own wallet via a shareable URL. Use when an agent needs the user to approve/execute a JSON-RPC request (e.g. eth_sendTransaction, personal_sign, eth_signTypedData_v4, wallet_sendCalls) and return the result (tx hash/signature) back to the agent, optionally via redirect_url.

Open Wallet (tx.steer.fun)

Generate a link the user opens in their browser. The page shows the request, prompts them to connect their wallet, switches to the requested chainId, then executes the JSON-RPC request.

Build The Link

Base URL:

https://tx.steer.fun/

Query params:

• method: JSON-RPC method name.
• chainId: integer chain id to execute on (the app will switch chains before execution).
• params: URL-encoded JSON (either an object or an array).
• redirect_url (optional): where to redirect after success/failure with the result.

redirect_url modes:

• Default: the app appends resultType/result (or error) query params to redirect_url.
• Template mode: if redirect_url contains {{...}}, the app replaces placeholders instead of appending query params.

Notes:

• If params is a JSON array, it is treated as the exact JSON-RPC params array.
• If params is a JSON object, the app will map it to common method shapes (e.g. fill from from the connected wallet when possible).
• Avoid double-encoding: params should be encoded exactly once (e.g. encodeURIComponent(JSON.stringify(params))). If you see %2522 in the URL, it was encoded twice.

Common Flows

Sign A Message (personal_sign)

Use a JSON object:

https://tx.steer.fun/?method=personal_sign&chainId=1&params=%7B%22message%22%3A%22hello%22%7D

Expected result: signature string.

Send A Transaction (eth_sendTransaction)

Use a JSON object (the app will set from from the connected wallet if omitted):

https://tx.steer.fun/?method=eth_sendTransaction&chainId=1&params=%7B%22to%22%3A%220x4c5Ce72478D6Ce160cb31Dd25fe6a15DC269592D%22%2C%22data%22%3A%220xd09de08a%22%7D

Expected result: tx hash.

Typed Data Sign (eth_signTypedData_v4)

Provide { address, typedData }:

https://tx.steer.fun/?method=eth_signTypedData_v4&chainId=1&params=%7B%22address%22%3A%220xYourAddress%22%2C%22typedData%22%3A%7B%22types%22%3A%7B%7D%2C%22domain%22%3A%7B%7D%2C%22primaryType%22%3A%22%22%2C%22message%22%3A%7B%7D%7D%7D

Expected result: signature string.

Batch Calls (wallet_sendCalls)

Provide { calls: [{ to, data }, ...] } (and optionally from):

https://tx.steer.fun/?method=wallet_sendCalls&chainId=1&params=%7B%22calls%22%3A%5B%7B%22to%22%3A%220x0000000000000000000000000000000000000000%22%2C%22data%22%3A%220x%22%7D%5D%7D

Expected result: wallet-dependent (often an id or tx hash).

Getting The Result Back

Option A: No redirect_url (manual copy)

If you omit redirect_url, the page shows a copyable response (or error) after execution.

In your message to the user, ask them to paste back:

• the tx hash / signature string, or
• the full JSON response (if it returns an object).

Option B: redirect_url (automatic return)

If you include redirect_url, the app redirects after success or failure.

It appends query params (default mode):

• On success:
  • resultType=string and result=<value> OR
  • resultType=json and result=<JSON.stringify(value)>
• On failure:
  • error=<message>

Template mode (no bridge, good for messaging apps):

• If redirect_url contains {{...}}, placeholders are replaced and no query params are appended.
• Placeholders:
  • {{result}}: URL-encoded result string (or URL-encoded JSON.stringify(result))
  • {{result_raw}}: unencoded result string (or JSON.stringify(result))
  • {{resultType}}: string or json
  • {{error}}: URL-encoded error message
  • {{error_raw}}: unencoded error message

Implementation note for agents:

• Consider generating a “compose draft” deep link into your chat with the user and using that as redirect_url so, after approval, the user lands in a pre-filled message back to you containing the result.

Example (Telegram share):

Note: Telegram's share endpoint works best when you include both url= and text=. If you omit url=, it may redirect to telegram.org instead of showing the share UI.

https://tx.steer.fun/?method=personal_sign&chainId=1&params=%7B%22message%22%3A%22hello%22%7D&redirect_url=https%3A%2F%2Ft.me%2Fshare%2Furl%3Furl%3Dhttps%253A%252F%252Ftx.steer.fun%252F%26text%3DSignature%253A%2520%7B%7Bresult%7D%7D

Safety Checks

• Always show the user what the request does in plain language (what contract, what function, what chain, what value) before asking them to open the link.
• Prefer least-privilege requests; avoid requesting permissions you do not need.