NEAR Intents: Simulating Intents

Test intents without modifying blockchain state using the simulate_intents function

The simulate_intents function runs intent code without modifying the Verifier contract's state. It accepts the same MultiPayload input as execute_intents.

• For intent structure and types, see Intent Types and Execution.
• For signing intents before simulation, see Signing Intents.

When to use simulations

Validate signatures

Verify that your intent's digital signature format is valid before executing

Test withdrawals

Ensure a withdrawal will work before committing to it

Check fees

See the fees that will be paid to the Verifier contract for a trade

Example simulation

Here's a valid, signed intent to trade 100 USDC for 100 USDT between Charlie and Drake:

{
  "signed": [
    {
      "standard": "nep413",
      "payload": {
        "recipient": "intents.near",
        "nonce": "Vij2xgAlKBKzwJcGrQQYQhiLk1HU5AVNH1M3PhtxosE=",
        "message": "{\"deadline\":\"2025-05-23T07:40:13.735337Z\",\"intents\":[{\"intent\":\"token_diff\",\"diff\":{\"nep141:usdc.near\":\"-100\",\"nep141:usdt.near\":\"100\"}}],\"signer_id\":\"charlie.near\"}"
      },
      "public_key": "ed25519:C3jXhkGhEx88Gj7XKtUziJKXEBMRaJ67bWFkxJikVxZ2",
      "signature": "ed25519:617X6QMiwFohRHqEuFwZ8aGU6Gn8PsH1DM3grArCYSKSvLz4wBPPGLzLPX3SLstLB331ESGPUToaPkUE7DvgefUu"
    },
    {
      "standard": "nep413",
      "payload": {
        "recipient": "intents.near",
        "nonce": "Vij2xgAlKBKzwJcGrQQYQhjtxxGCsZQhM2DP7btPexE=",
        "message": "{\"deadline\":\"2025-05-23T07:40:13.753085Z\",\"intents\":[{\"intent\":\"token_diff\",\"diff\":{\"nep141:usdc.near\":\"100\",\"nep141:usdt.near\":\"-100\"}}],\"signer_id\":\"drake.near\"}"
      },
      "public_key": "ed25519:C3jXhkGhEx88Gj7XKtUziJKXEBMRaJ67bWFkxJikVxZ2",
      "signature": "ed25519:3mLCEKyhofYLVakC9qgyb2FWh4L3jQxnUNyBHxYMTC13bo9y4AeqRh29dDYC4ZAQk4Z4mA2QZL8y7KGGKp5Pc3S1"
    }
  ]
}

Calling simulate_intents produces:

{
  "intents_executed": [
    {
      "intent_hash": "5GpL6PsUQVHFYAk5FWEwBUaEQqcZkc2SjTvPYHgHAnx8",
      "account_id": "charlie.near",
      "nonce": "Vij2xgAlKBKzwJcGrQQYQhiLk1HU5AVNH1M3PhtxosE="
    },
    {
      "intent_hash": "4ejradLAAPBhBVAn6tBYExpuj2VCn5f5VEBfVajNXiXk",
      "account_id": "drake.near",
      "nonce": "Vij2xgAlKBKzwJcGrQQYQhjtxxGCsZQhM2DP7btPexE="
    }
  ],
  "logs": [
    "EVENT_JSON:{\"data\":[{\"account_id\":\"charlie.near\",\"diff\":{\"nep141:usdc.near\":\"-100\",\"nep141:usdt.near\":\"100\"},\"intent_hash\":\"5GpL6PsUQVHFYAk5FWEwBUaEQqcZkc2SjTvPYHgHAnx8\"}],\"event\":\"token_diff\",\"standard\":\"dip4\",\"version\":\"0.3.0\"}",
    "EVENT_JSON:{\"data\":[{\"account_id\":\"drake.near\",\"diff\":{\"nep141:usdc.near\":\"100\",\"nep141:usdt.near\":\"-100\"},\"intent_hash\":\"4ejradLAAPBhBVAn6tBYExpuj2VCn5f5VEBfVajNXiXk\"}],\"event\":\"token_diff\",\"standard\":\"dip4\",\"version\":\"0.3.0\"}",
    "EVENT_JSON:{\"data\":[{\"account_id\":\"charlie.near\",\"intent_hash\":\"5GpL6PsUQVHFYAk5FWEwBUaEQqcZkc2SjTvPYHgHAnx8\",\"nonce\":\"Vij2xgAlKBKzwJcGrQQYQhiLk1HU5AVNH1M3PhtxosE=\"},{\"account_id\":\"drake.near\",\"intent_hash\":\"4ejradLAAPBhBVAn6tBYExpuj2VCn5f5VEBfVajNXiXk\",\"nonce\":\"Vij2xgAlKBKzwJcGrQQYQhjtxxGCsZQhM2DP7btPexE=\"}],\"event\":\"intents_executed\",\"standard\":\"dip4\",\"version\":\"0.3.0\"}"
  ],
  "min_deadline": "2025-05-23T07:40:13.735337Z",
  "state": {
    "fee": 100,
    "current_salt": "252812b3"
  }
}

Response fields

Field	Description
intents_executed	Array of intent events collected during simulation.
intents_executed[].intent_hash	Unique hash identifying the intent.
intents_executed[].account_id	NEAR account that signed the intent.
intents_executed[].nonce	Base64-encoded nonce used by the intent.
logs	Array of DIP-4 event JSON strings that would be emitted during execution.
min_deadline	Earliest deadline among all intents in the batch.
state.fee	Current fee in pips.
state.current_salt	Current 4-byte salt value (hex-encoded).

[!NOTE]

Fees are expressed in pips—100 pips equals 0.01%.

[!TIP]

Use current_salt from the simulation response when constructing versioned nonces. A nonce is only valid if its embedded salt matches one of the salts in the contract's registry.

Simulation outputs may include additional data in future updates. Contact the NEAR Intents team if your application requires more detailed output.

Accuracy of simulations

Simulated results are designed to closely match actual execution outcomes through extensive testing.

However, due to the asynchronous nature of the NEAR blockchain, it's not possible to simulate intents exactly as they would execute in reality.

[!TIP]

To date, simulation and execution results have always matched. If you discover a case where they differ, please contact the NEAR Intents team and report it as a bug.

[!WARNING]

Simulations reflect only side effects within the Verifier contract and exclude those from external asynchronous calls.