API integration guide for students to enroll in a course and commit to an assignment

Commit to Assignment

A student commits to a specific module assignment within a course. If the student is not yet enrolled, this transaction handles enrollment and the first assignment commitment in a single step. If already enrolled, it commits to an additional assignment. The state machine handles both cases transparently.

Summary

Property	Value
System	Course
Role	Student
Type Key	`course_enroll`
Build Endpoint	`POST /api/v2/tx/course/student/assignment/commit`
DB Sync	No
Service Fee	0 ADA
Est. Wallet Cost	~2.14 ADA

The estimated wallet cost breaks down as: transaction fee ~0.40 ADA + course state deposit ~1.45 ADA + global state delta ~0.29 ADA. The course state deposit is recoverable when the student claims their course credential.

Build Transaction

Endpoint

POST /api/v2/tx/course/student/assignment/commit

Request Body

{
  "alias": "student1",
  "course_id": "a1b2c3d4e5f6a1b2c3d4e5f6a1b2c3d4e5f6a1b2c3d4e5f6a1b2c3d4",
  "slt_hash": "9f3a1b2c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b7c8d9e0f1a",
  "assignment_info": "e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6",
  "initiator_data": {
    "usedAddresses": ["addr1qx2fxv..."],
    "changeAddress": "addr1qx2fxv..."
  }
}

Field	Type	Required	Description
`alias`	`string` (Alias)	Yes	The student's access token alias. Must have a minted access token.
`course_id`	`string` (GYMintingPolicyId)	Yes	The 56-character hex course policy ID.
`slt_hash`	`string` (SltHash)	Yes	The 64-character hex hash of the module the student is committing to.
`assignment_info`	`string`	Yes	Evidence hash for the assignment — a hash of the student's submitted work or a reference to it.
`initiator_data`	`WalletData`	No	Object containing `usedAddresses` (string[]) and `changeAddress` (string). Note: this endpoint uses `initiator_data` rather than `walletData`.

Response

{
  "unsigned_tx": "84a800..."
}

Note that this endpoint returns unsigned_tx rather than unsignedTxCBOR. The value is the same — an unsigned transaction CBOR ready for the wallet to sign.

Register Transaction

After the user signs and submits the transaction, register it with the state machine:

POST /api/v2/tx/register

{
  "tx_hash": "64-char hex hash from wallet.submitTx()",
  "tx_type": "course_enroll"
}

No metadata is required. Enrollment status is tracked entirely on-chain. The type key is course_enroll because this endpoint replaces the original enrollment endpoint — a commit is effectively an enrollment-plus-assignment in one step.

Endpoint	Description
`GET /api/v2/courses/{course_id}`	Fetch course details including the module list and their SLT hashes

Example: Full Lifecycle

const API_URL = "https://api.andamio.io";

// 1. Build
const buildRes = await fetch(`${API_URL}/api/v2/tx/course/student/assignment/commit`, {
  method: "POST",
  headers: {
    "Content-Type": "application/json",
    "X-API-Key": API_KEY,
    "Authorization": `Bearer ${userJwt}`,
  },
  body: JSON.stringify({
    alias: "student1",
    course_id: "a1b2c3d4e5f6a1b2c3d4e5f6a1b2c3d4e5f6a1b2c3d4e5f6a1b2c3d4",
    slt_hash: "9f3a1b2c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b7c8d9e0f1a",
    assignment_info: "e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4e5f6",
    initiator_data: {
      usedAddresses: [walletAddress],
      changeAddress: walletAddress,
    },
  }),
});
const { unsigned_tx } = await buildRes.json();
const signedTx = await wallet.signTx(unsigned_tx);

// 3. Submit
const txHash = await wallet.submitTx(signedTx);

// 4. Register
await fetch(`${API_URL}/api/v2/tx/register`, {
  method: "POST",
  headers: {
    "Content-Type": "application/json",
    "X-API-Key": API_KEY,
    "Authorization": `Bearer ${userJwt}`,
  },
  body: JSON.stringify({
    tx_hash: txHash,
    tx_type: "course_enroll",
  }),
});

// 5. Monitor (SSE)
const events = new EventSource(
  `${API_URL}/api/v2/tx/stream/${txHash}`
);
events.addEventListener("state_change", (e) => {
  const data = JSON.parse(e.data);
  console.log(`State: ${data.old_state} → ${data.new_state}`);
});
events.addEventListener("complete", (e) => {
  const data = JSON.parse(e.data);
  console.log(`Final: ${data.final_state}`);
  events.close();
});