Infrastructure

Canister Help

Display a human-readable summary of a canister's interface given its mainnet canister ID or a human-readable name. Like --help but for canisters. Only for mainnet canisters — for local canisters, read the generated .did file in your project directly.

Skill ID
canhelp
Category
Infrastructure
License
Apache-2.0
Compatibility
icp-cli >= 0.1.0
Last updated
Source

Trust note. This page is a static, pre-rendered mirror of dfinity/icskills/skills/canhelp/SKILL.md. The canonical source is the Git commit it was built from. Licensed Apache-2.0.

Given a canister ID or name in $ARGUMENTS, fetch and summarize its Candid interface.

Steps

  1. Resolve the canister ID by running the resolve script from the skill’s base directory:

    ./scripts/resolve-canister-id.sh "$ARGUMENTS"

    If $ARGUMENTS is already a valid principal, the script echoes it back. Otherwise, it queries the IC Dashboard API and outputs matches as <canister-id> <name> (one per line).

    • If there is a single result, clearly display the resolved canister ID and use it directly.
    • If there are multiple results, present the list to the user and ask them to pick one before continuing.

  2. Fetch the Candid interface using the resolved canister ID:

    ./scripts/fetch-candid.sh <resolved-canister-id>

    The script outputs the path to the downloaded .did file.

  3. Read the file using the Read tool.

  4. Present the output as a readable summary with the following structure:

    Canister <canister-id>

    Query methods:

    • method_name(arg1: type1, arg2: type2) → return_type — one-line description if inferable from the name

    Update methods:

    • method_name(arg1: type1) → return_type

    Types:

    • List any custom record/variant types defined in the interface, with their fields

Guidelines

  • Group methods by query vs update
  • Sort methods alphabetically within each group
  • For complex nested types, show the top-level structure and note nesting
  • If the candid is very large (>100 methods), show a summary count and list only the most important-looking methods, offering to show the full list on request
  • If the fetch succeeds, but the Candid interface is empty,explain that the canister is not exposing its Candid interface in the wasm metadata
  • If the fetch fails, suggest the user verify the canister ID and that icp is installed