Elixir ICP Agent for the Internet Computer View Source

The ICP Agent library supports both queries and calls to the Internet Computer. All authentication is done using Secp256k1 keys handled by the DiodeClient.Wallet struct.

Query example

This examples uses the get_latest_sns_version_pretty method from the SNS-wasm system canister. It's a publicly available method, so no authentication is needed. We're generating a new wallet ad-hoc and using it to query the canister.

> [versions] = ICPAgent.query("qaa6y-5yaaa-aaaaa-aaafa-cai", DiodeClient.Wallet.new(), "get_latest_sns_version_pretty")
[
  [
    {"Ledger Index",
     "2adc74fe5667f26ea4c4006309d99b1dfa71787aa43a5c168cb08ec725677996"},
    {"Governance",
     "bd936ef6bb878df87856a0b0c46034a242a88b7f1eeff5439daf6278febca6b7"},
    {"Ledger Archive",
     "f94cf1db965b7042197e5894fef54f5f413bb2ebc607ff0fb59c9d4dfd3babea"},
    {"Swap", "8313ac22d2ef0a0c1290a85b47f235cfa24ca2c96d095b8dbed5502483b9cd18"},
    {"Root", "431cb333feb3f762f742b0dea58745633a2a2ca41075e9933183d850b4ddb259"},
    {"Ledger",
     "25071c2c55ad4571293e00d8e277f442aec7aed88109743ac52df3125209ff45"}
  ]
]

Call example

Calls and queries both support providing arguments and types in Candid format specification. These are some examples of call structures to give a better understanding of how the types are specified.

# Generating a new private key as identity
> wallet = DiodeClient.Wallet.new()

# Call with passing two blobs as an argument
> [200] = ICPAgent.call(canister_id, wallet, "test_blob_input", [:blob, :blob], ["blob_a", "blob_b"])

# Call with passing a record as an argument
> [3] = ICPAgent.call(canister_id, wallet, "test_record_input", [{:record, {:nat32, :nat32}}], [{1, 2}])

# Call with passing a record with named fields as an argument
> [3] = ICPAgent.call(canister_id, wallet, "test_named_record_input", [{:record, %{a: :nat32, b: :nat32}}], [{a: 1, b: 2}])

# Call with passing a vector of records as an argument
> [200] = ICPAgent.call(canister_id, wallet, "test_vec_input", [{:vec, {:record, {:blob, :blob}}}], [[{"blob_a", "blob_b"}]])

Limits

• Only secp256k1 keys are supported.
• Did files are not supported and instead types for a call/query must be manually specified.

Installation

If available in Hex, the package can be installed by adding icp_agent to your list of dependencies in mix.exs:

def deps do
  [
    {:icp_agent, "~> 0.1.0"}
  ]
end

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/icp_agent.