Canhelp

Name: Canhelp
Author: dfinity

dfinity/icskills

120 installs
28 repo stars
Updated August 4, 2026
dfinity/icskills

Fetch and summarize a mainnet IC canister's Candid interface from its canister ID or human-readable name.

About

Given a mainnet canister ID or name, fetches its Candid interface and prints a human-readable summary of its query methods, update methods, and types. A developer uses it to inspect what a mainnet IC canister exposes, like --help for canisters.

Resolves a mainnet canister ID or name and fetches its Candid interface
Prints a grouped, readable summary of query/update methods and types

Canhelp by the numbers

120 all-time installs (skills.sh)
Ranked #157 of 479 Web3 & Blockchain skills by installs in the Skillselion catalog
Data as of Aug 5, 2026 (Skillselion catalog sync)

npx skills add https://github.com/dfinity/icskills --skill canhelp

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Installs	120
repo stars	★ 28
Last updated	August 4, 2026
Repository	dfinity/icskills ↗

What it does

Fetch and summarize a mainnet IC canister's Candid interface from its canister ID or human-readable name.

Files

SKILL.mdMarkdownGitHub ↗

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

#!/bin/bash
set -euo pipefail

if ! command -v icp &>/dev/null; then
    echo "Error: 'icp' CLI not found. Install it from https://dfinity.github.io/icp-cli" >&2
    exit 1
fi

CANISTER_ID="${1:?Usage: fetch-candid.sh <canister-id>}"
OUT="/tmp/candid_${CANISTER_ID}.did"

icp canister metadata "$CANISTER_ID" candid:service --network ic > "$OUT"
echo "$OUT"

#!/bin/bash
set -euo pipefail

INPUT="${1:?Usage: resolve-canister-id.sh <canister-id-or-name>}"

# Principal: Base32(CRC32 · blob) grouped into 5-char chunks separated by dashes.
# Each group is exactly 5 lowercase alphanumeric chars, except the last which is 1-5.
# Max 63 chars (29-byte blob → 53 base32 chars + 10 dashes). Must have at least 2 groups.
if [[ "$INPUT" =~ ^[a-z2-7]{5}(-[a-z2-7]{5})*(-[a-z2-7]{1,5})$ ]]; then
    echo "$INPUT"
    exit 0
fi

# Otherwise, query IC Dashboard API for name-based lookup
QUERY=$(python3 -c "import urllib.parse, sys; print(urllib.parse.quote(sys.argv[1]))" "$INPUT")
RESPONSE=$(curl -sf "https://ic-api.internetcomputer.org/api/v4/canisters?format=json&has_name=true&query=${QUERY}&limit=50")

python3 -c "
import sys, json
data = json.load(sys.stdin)
entries = data.get('data', [])
if not entries:
    print('Error: no canister found matching \"$INPUT\"', file=sys.stderr)
    sys.exit(1)
for e in entries:
    print(f\"{e['canister_id']}  {e.get('name', 'N/A')}\")
" <<< "$RESPONSE"