> For the complete documentation index, see [llms.txt](https://docs.tronsave.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.tronsave.io/developers/legacy-api-v0/signed-tx.md). # Buy — Signed Transaction {% hint style="warning" %} **Legacy API.** This page documents the v0 signed-transaction flow under the `/v0/` base path. New integrations should use the current API. See [Buy with Signed Transaction (v2)](/developers/api-reference/buy-resources/signed-tx.md). {% endhint %} The signed-transaction flow lets you buy Energy by paying TRX directly from your own wallet — no API key required, since the TRX transfer is signed with your private key. There are three steps: 1. [Estimate TRX](#step-1-estimate-trx) — calculate the TRX needed for the desired amount and rental duration. 2. [Get a signed transaction](#step-2-get-a-signed-transaction) — sign a TRX transfer to the TronSave fund address, either yourself or via the API. 3. [Create an order](#step-3-create-an-order) — submit the signed transaction to place the buy order. {% hint style="info" %} **Before you start:** make sure you have the wallet's private key and that the wallet holds enough TRX to cover the estimated cost. {% endhint %} The mainnet base URL is `https://api.tronsave.io`. For testing on the TRON Nile testnet, use `https://api-dev.tronsave.io`. See [Environments](/developers/environments.md). | Step | Method | Mainnet | Testnet (Nile) | | ---------------------- | ------ | ----------------------------------------- | --------------------------------------------- | | Estimate TRX | `POST` | `https://api.tronsave.io/v0/estimate-trx` | `https://api-dev.tronsave.io/v0/estimate-trx` | | Get Signed Transaction | `POST` | `https://api.tronsave.io/v0/signed-tx` | `https://api-dev.tronsave.io/v0/signed-tx` | | Create Order | `POST` | `https://api.tronsave.io/v0/buy-energy` | `https://api-dev.tronsave.io/v0/buy-energy` | *** ## Step 1: Estimate TRX Calculate the TRX needed for a given resource amount and rental duration. The response gives you the `unit_price` and the `estimate_trx` you must transfer in Step 2. **`POST`** **`https://api.tronsave.io/v0/estimate-trx`** {% hint style="info" %} **Rate limit:** 15 requests per 1 second. {% endhint %} ### Headers | Header | Value | Required | | -------------- | ------------------ | -------- | | `Content-Type` | `application/json` | Yes | ### Request params
FieldPositionTypeRequiredDescription
amountbodynumbertrueThe number of resources
buy_energy_typebodystring, numbertrue

"FAST", "MEDIUM", "SLOW" or number:


-"FAST": If market ready to fill = 100%, FAST = MEDIUM. If the market ready to fill < 100%, FAST = MEDIUM + 10. If market ready to fill = 0%, FAST = SLOW + 20.

-"MEDIUM": The lowest price for the maximum market fill for this order. If market ready to fill = 0%, MEDIUM = SLOW + 10.

-"SLOW": The lowest price that can be set for this order.

-If the price is a number, the price unit is equal to SUN

duration_millisecbodynumbertrueThe duration of the bought resource, time unit is equal to millisecond.
request_addressbodystringfalseThe address of requester.
target_addressbodystringfalseThe address of receiver resource.
is_partialbodybooleanfalseAllow the order to be filled partially or not.
### Request body example ```json { "amount": 100000, "buy_energy_type": "MEDIUM", "duration_millisec": 259200000 } ``` ### Responses
FieldTypeRequiredDescription
unit_pricenumbertrueprice in SUN of energy that fit with your buy_energy_type
duration_millisecnumbertrue
available_energynumbertruetotal amount available energy on TronSave market that match with unit_price
estimate_trxnumbertrueestimate total trx value will pay for buy all available_energy with price is unit_price in duration_millisec
#### Success ```json { "unit_price": 45, "duration_millisec": 259200000, "available_energy": 4298470, "estimate_trx": 13500000 } ``` The `estimate_trx` value is returned in SUN (1 TRX = 1,000,000 SUN). #### Error This endpoint does not require an `apikey` header — the signed-transaction flow authenticates through the wallet-signed TRX transfer, so no authentication error applies here. A request with a missing or invalid field returns a `400 Bad Request` whose `message` names the offending field: ```json { "statusCode": 400, "code": "FST_ERR_VALIDATION", "error": "Bad Request", "message": "body must have required property 'amount'" } ``` *** ## Step 2: Get a signed transaction You need a signed TRX transfer of `estimate_trx` SUN from the buyer's address to the TronSave fund address. You can build it yourself, or let the API do it. ### TronSave fund address {% tabs %} {% tab title="MAINNET" %} ``` TWZEhq5JuUVvGtutNgnRBATbF8BnHGyn4S ``` {% endtab %} {% tab title="Nile (for testing)" %} {% hint style="warning" %} This fund address is for testing purposes only on the TRON Nile network. {% endhint %} ``` TATT1UzHRikft98bRFqApFTsaSw73ycfoS ``` {% endtab %} {% endtabs %} ### Option 1: Write your own function Using `tronWeb`, build a `sendTrx` transfer for `estimate_trx` (from Step 1) and sign it with the buyer's private key: ```javascript const dataSendTrx = await tronWeb.transactionBuilder.sendTrx('TRONSAVE_FUND_ADDRESS', estimate_trx, 'BUYER_ADDRESS') const signed_tx = await tronWeb.trx.sign(dataSendTrx, 'PRIVATE_KEY'); ``` {% hint style="info" %} * `BUYER_ADDRESS` is the buyer's public address. * `PRIVATE_KEY` is the buyer's private key. * `TRONSAVE_FUND_ADDRESS` is the TronSave fund address shown above. {% endhint %} ### Option 2: Use the Get Signed Transaction API **`POST`** **`https://api.tronsave.io/v0/signed-tx`** {% hint style="info" %} **Rate limit:** 15 requests per 1 second. {% endhint %} #### Headers | Header | Value | Required | | -------------- | ------------------ | -------- | | `Content-Type` | `application/json` | Yes | #### Request params
FieldPositionTypeRequiredDescription
addressbodystringtrueThe buyer's public address
private_keybodystringtrueThe buyer's private key
estimate_trxbodynumbertrueThe amount of TRX to be paid is calculated in SUN. (estimate_trx from Step 1)
#### Request body example ```json { "address": "TM6ZeEgpefyGWeMLuzSbfqTGkPv8Z65432", "private_key": "{{yourprivateKey}}", "estimate_trx": 13500000 } ``` #### Responses **Success** ```json { "visible": false, "txID": "446eed36e31249b98b201db2e81a3825b185f1a3d8b2fea348b24fc021e58e0d", "raw_data": { "contract": [ { "parameter": { "value": { "amount": 13500000, "owner_address": "417a0d868d1418c9038584af1252f85d486502eec0", "to_address": "41055756f33f419278d9ea059bd2b21120e6add748" }, "type_url": "type.googleapis.com/protocol.TransferContract" }, "type": "TransferContract" } ], "ref_block_bytes": "0713", "ref_block_hash": "6c5f7686f4176139", "expiration": 1691465106000, "timestamp": 1691465046758 }, "raw_data_hex": "0a02071322086c5f7686f417613940d084b5999d315a68080112640a2d747970652e676f6f676c65617069732e636f6d2f70726f746f636f6c2e5472616e73666572436f6e747261637412330a15417a0d868d1418c9038584af1252f85d486502eec0121541055756f33f419278d9ea059bd2b21120e6add74818e0fcb70670e6b5b1999d31", "signature": ["xxxxxxxxx"] } ``` **Error** No `apikey` header is required for this endpoint. A request with a missing or invalid field returns a `400 Bad Request` whose `message` names the offending field: ```json { "statusCode": 400, "code": "FST_ERR_VALIDATION", "error": "Bad Request", "message": "body must have required property 'estimate_trx'" } ``` *** ## Step 3: Create an order Submit the signed transaction (from Step 2) together with the order parameters to place the Energy purchase. **`POST`** **`https://api.tronsave.io/v0/buy-energy`** {% hint style="info" %} **Rate limit:** 15 requests per 1 second. {% endhint %} ### Headers | Header | Value | Required | | -------------- | ------------------ | -------- | | `Content-Type` | `application/json` | Yes | {% hint style="info" %} This endpoint authenticates through the `signed_tx` you submit — the TRX payment is signed by your own wallet — so an `apikey` header is not required. {% endhint %} ### Request params
FieldTypeRequiredDescription
resource_typestringtrue"ENERGY"
unit_pricenumbertruePrice unit is equal to SUN.
allow_partial_fillbooleantrueAllow the order to be filled partially or not
target_addressstringtrueResource receiving address
duration_millisecnumbertrueThe duration of the bought resource, time unit is equal to millisec.
tx_idstringtrueTransaction ID
signed_txSignedTransactiontrueSigned transaction, note that it is a JSON object (the signed_tx from Step 2)
only_create_when_fulfilledBooleanfalse

[true] => order only create when it can be fulfilled

[false] => order will create even it can not be fulfilled

Default value: false

max_price_acceptedNumberfalseOnly create order when the estimate price less than this value.
add_order_incompleteBooleanfalse

[true] => order only create when there has no same parameters order is not complete in order list

[false] => order will create even there has no same parameters order is not complete in order list

Default value: false

### Request body example ```json { "resource_type": "ENERGY", "unit_price": 45, "allow_partial_fill": true, "target_address": "TM6ZeEgpefyGWeMLuzSbfqTGkPv8Z6Jm4X", "duration_millisec": 259200000, "tx_id": "446eed36e31249b98b201db2e81a3825b185f1a3d8b2fea348b24fc021e58e0d", "signed_tx": { "visible": false, "txID": "446eed36e31249b98b201db2e81a3825b185f1a3d8b2fea348b24fc021e58e0d", "raw_data": { "contract": [ { "parameter": { "value": { "amount": 13500000, "owner_address": "417a0d868d1418c9038584af1252f85d486502eec0", "to_address": "41055756f33f419278d9ea059bd2b21120e6add748" }, "type_url": "type.googleapis.com/protocol.TransferContract" }, "type": "TransferContract" } ], "ref_block_bytes": "0713", "ref_block_hash": "6c5f7686f4176139", "expiration": 1691465106000, "timestamp": 1691465046758 }, "raw_data_hex": "0a02071322086c5f7686f417613940d084b5999d315a68080112640a2d747970652e676f6f676c65617069732e636f6d2f70726f746f636f6c2e5472616e73666572436f6e747261637412330a15417a0d868d1418c9038584af1252f85d486502eec0121541055756f33f419278d9ea059bd2b21120e6add74818e0fcb70670e6b5b1999d31", "signature": ["xxxxxxxxx"] }, "only_create_when_fulfilled": false, "max_price_accepted": 200, "add_order_incomplete": false } ``` ### Responses #### Success ```json { "message": "651d2306e55c073f6ca0992e" } ``` The `message` value is the `order_id` of the created order. #### Error This endpoint authenticates through the submitted `signed_tx`, so no `apikey` header and no authentication error apply. A request with a missing or invalid field returns a `400 Bad Request` whose `message` names the offending field: ```json { "statusCode": 400, "code": "FST_ERR_VALIDATION", "error": "Bad Request", "message": "body must have required property 'signed_tx'" } ``` *** ## Request examples The examples below show the full flow: estimate, sign the TRX transfer to the fund address, then create the order. Replace `YOUR_TRON_ADDRESS`, the private key, and the fund address as needed. Signing the TRX transfer (Step 2, Option 1) typically uses a TRON library; the cURL example uses the API (Step 2, Option 2) instead. {% tabs %} {% tab title="cURL" %} ```bash # Step 1: Estimate TRX curl -X POST https://api.tronsave.io/v0/estimate-trx \ -H "Content-Type: application/json" \ -d '{ "amount": 100000, "buy_energy_type": "MEDIUM", "duration_millisec": 259200000 }' # Step 2: Get a signed transaction (Option 2) curl -X POST https://api.tronsave.io/v0/signed-tx \ -H "Content-Type: application/json" \ -d '{ "address": "YOUR_TRON_ADDRESS", "private_key": "YOUR_PRIVATE_KEY", "estimate_trx": 13500000 }' # Step 3: Create the order (use the signed_tx returned above) curl -X POST https://api.tronsave.io/v0/buy-energy \ -H "Content-Type: application/json" \ -d '{ "resource_type": "ENERGY", "unit_price": 45, "allow_partial_fill": true, "target_address": "YOUR_TRON_ADDRESS", "duration_millisec": 259200000, "tx_id": "446eed36e31249b98b201db2e81a3825b185f1a3d8b2fea348b24fc021e58e0d", "signed_tx": { "visible": false, "txID": "446eed36...", "raw_data": {}, "raw_data_hex": "0a020713...", "signature": ["xxxxxxxxx"] }, "only_create_when_fulfilled": false, "max_price_accepted": 200, "add_order_incomplete": false }' ``` {% endtab %} {% tab title="JavaScript" %} ```javascript // Requires tronweb for signing the TRX transfer. const TRONSAVE_API_URL = "https://api.tronsave.io"; const TRONSAVE_FUND_ADDRESS = "TWZEhq5JuUVvGtutNgnRBATbF8BnHGyn4S"; // Step 1: Estimate TRX const estimateRes = await fetch(`${TRONSAVE_API_URL}/v0/estimate-trx`, { method: "POST", headers: { "Content-Type": "application/json" }, body: JSON.stringify({ amount: 100000, buy_energy_type: "MEDIUM", duration_millisec: 259200000, }), }); const { unit_price, duration_millisec, estimate_trx } = await estimateRes.json(); // Step 2 (Option 1): Sign the TRX transfer to the fund address const dataSendTrx = await tronWeb.transactionBuilder.sendTrx( TRONSAVE_FUND_ADDRESS, estimate_trx, "YOUR_TRON_ADDRESS" ); const signed_tx = await tronWeb.trx.sign(dataSendTrx, "YOUR_PRIVATE_KEY"); // Step 3: Create the order const orderRes = await fetch(`${TRONSAVE_API_URL}/v0/buy-energy`, { method: "POST", headers: { "Content-Type": "application/json" }, body: JSON.stringify({ resource_type: "ENERGY", unit_price, allow_partial_fill: true, target_address: "YOUR_TRON_ADDRESS", duration_millisec, tx_id: signed_tx.txID, signed_tx, only_create_when_fulfilled: false, max_price_accepted: 200, add_order_incomplete: false, }), }); console.log(await orderRes.text()); ``` {% endtab %} {% tab title="Python" %} ```python import requests TRONSAVE_API_URL = "https://api.tronsave.io" # Step 1: Estimate TRX estimate = requests.post( f"{TRONSAVE_API_URL}/v0/estimate-trx", json={ "amount": 100000, "buy_energy_type": "MEDIUM", "duration_millisec": 259200000, }, ).json() unit_price = estimate["unit_price"] duration_millisec = estimate["duration_millisec"] estimate_trx = estimate["estimate_trx"] # Step 2 (Option 2): Get a signed transaction from the API signed_tx = requests.post( f"{TRONSAVE_API_URL}/v0/signed-tx", json={ "address": "YOUR_TRON_ADDRESS", "private_key": "YOUR_PRIVATE_KEY", "estimate_trx": estimate_trx, }, ).json() # Step 3: Create the order order = requests.post( f"{TRONSAVE_API_URL}/v0/buy-energy", json={ "resource_type": "ENERGY", "unit_price": unit_price, "allow_partial_fill": True, "target_address": "YOUR_TRON_ADDRESS", "duration_millisec": duration_millisec, "tx_id": signed_tx["txID"], "signed_tx": signed_tx, "only_create_when_fulfilled": False, "max_price_accepted": 200, "add_order_incomplete": False, }, ).json() print(order) ``` {% endtab %} {% tab title="Java" %} ```java import java.net.URI; import java.net.http.HttpClient; import java.net.http.HttpRequest; import java.net.http.HttpResponse; public class BuyWithSignedTx { static final String TRONSAVE_API_URL = "https://api.tronsave.io"; static String post(HttpClient client, String path, String body) throws Exception { HttpRequest request = HttpRequest.newBuilder() .uri(URI.create(TRONSAVE_API_URL + path)) .header("Content-Type", "application/json") .POST(HttpRequest.BodyPublishers.ofString(body)) .build(); return client.send(request, HttpResponse.BodyHandlers.ofString()).body(); } public static void main(String[] args) throws Exception { HttpClient client = HttpClient.newHttpClient(); // Step 1: Estimate TRX String estimate = post(client, "/v0/estimate-trx", """ { "amount": 100000, "buy_energy_type": "MEDIUM", "duration_millisec": 259200000 } """); System.out.println(estimate); // Step 2 (Option 2): Get a signed transaction from the API String signedTx = post(client, "/v0/signed-tx", """ { "address": "YOUR_TRON_ADDRESS", "private_key": "YOUR_PRIVATE_KEY", "estimate_trx": 13500000 } """); System.out.println(signedTx); // Step 3: Create the order (embed the signedTx JSON from Step 2) String order = post(client, "/v0/buy-energy", """ { "resource_type": "ENERGY", "unit_price": 45, "allow_partial_fill": true, "target_address": "YOUR_TRON_ADDRESS", "duration_millisec": 259200000, "tx_id": "446eed36e31249b98b201db2e81a3825b185f1a3d8b2fea348b24fc021e58e0d", "signed_tx": %s, "only_create_when_fulfilled": false, "max_price_accepted": 200, "add_order_incomplete": false } """.formatted(signedTx)); System.out.println(order); } } ``` {% endtab %} {% tab title="Go" %} ```go package main import ( "bytes" "fmt" "io" "net/http" ) const tronsaveAPIURL = "https://api.tronsave.io" func post(path string, body []byte) string { req, err := http.NewRequest(http.MethodPost, tronsaveAPIURL+path, bytes.NewBuffer(body)) if err != nil { panic(err) } req.Header.Set("Content-Type", "application/json") resp, err := http.DefaultClient.Do(req) if err != nil { panic(err) } defer resp.Body.Close() out, _ := io.ReadAll(resp.Body) return string(out) } func main() { // Step 1: Estimate TRX estimate := post("/v0/estimate-trx", []byte(`{ "amount": 100000, "buy_energy_type": "MEDIUM", "duration_millisec": 259200000 }`)) fmt.Println(estimate) // Step 2 (Option 2): Get a signed transaction from the API signedTx := post("/v0/signed-tx", []byte(`{ "address": "YOUR_TRON_ADDRESS", "private_key": "YOUR_PRIVATE_KEY", "estimate_trx": 13500000 }`)) fmt.Println(signedTx) // Step 3: Create the order (embed the signed_tx JSON from Step 2) order := post("/v0/buy-energy", []byte(`{ "resource_type": "ENERGY", "unit_price": 45, "allow_partial_fill": true, "target_address": "YOUR_TRON_ADDRESS", "duration_millisec": 259200000, "tx_id": "446eed36e31249b98b201db2e81a3825b185f1a3d8b2fea348b24fc021e58e0d", "signed_tx": {}, "only_create_when_fulfilled": false, "max_price_accepted": 200, "add_order_incomplete": false }`)) fmt.Println(order) } ``` {% endtab %} {% tab title="Rust" %} ```rust // Cargo.toml: // reqwest = { version = "0.12", features = ["blocking", "json"] } // serde_json = "1" use reqwest::blocking::Client; use serde_json::{json, Value}; const TRONSAVE_API_URL: &str = "https://api.tronsave.io"; fn post(client: &Client, path: &str, body: &Value) -> Value { client .post(format!("{TRONSAVE_API_URL}{path}")) .header("Content-Type", "application/json") .json(body) .send() .unwrap() .json() .unwrap() } fn main() -> Result<(), Box> { let client = Client::new(); // Step 1: Estimate TRX let estimate = post(&client, "/v0/estimate-trx", &json!({ "amount": 100000, "buy_energy_type": "MEDIUM", "duration_millisec": 259200000 })); println!("{estimate}"); // Step 2 (Option 2): Get a signed transaction from the API let signed_tx = post(&client, "/v0/signed-tx", &json!({ "address": "YOUR_TRON_ADDRESS", "private_key": "YOUR_PRIVATE_KEY", "estimate_trx": estimate["estimate_trx"] })); println!("{signed_tx}"); // Step 3: Create the order let order = post(&client, "/v0/buy-energy", &json!({ "resource_type": "ENERGY", "unit_price": estimate["unit_price"], "allow_partial_fill": true, "target_address": "YOUR_TRON_ADDRESS", "duration_millisec": estimate["duration_millisec"], "tx_id": signed_tx["txID"], "signed_tx": signed_tx, "only_create_when_fulfilled": false, "max_price_accepted": 200, "add_order_incomplete": false })); println!("{order}"); Ok(()) } ``` {% endtab %} {% endtabs %} ## Next steps * Migrate to the current API: [Buy with Signed Transaction (v2)](/developers/api-reference/buy-resources/signed-tx.md). * [Authentication](/developers/authentication.md) and [Environments](/developers/environments.md). * [Glossary](/concepts/glossary.md) for Energy, Bandwidth, TRX, and SUN definitions. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.tronsave.io/developers/legacy-api-v0/signed-tx.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.