Canister Settings Reference

Complete reference for all canister settings available in icp-cli.

Canister settings control resource allocation, behavior, and runtime configuration. They can be specified:

At the canister level in icp.yaml or canister.yaml
At the environment level to override per-environment

Settings

compute_allocation

Guaranteed percentage of compute capacity.

Property	Value
Type	Integer
Range	0-100
Default	0 (best effort)

settings:
  compute_allocation: 10

Higher values guarantee more compute but cost more cycles.

memory_allocation

Fixed memory reservation in bytes.

Property	Value
Type	Integer
Unit	Bytes
Default	Dynamic allocation

settings:
  memory_allocation: 4294967296  # 4GB

If not set, the canister uses dynamic memory allocation.

freezing_threshold

Time in seconds before the canister freezes due to low cycles.

Property	Value
Type	Integer
Unit	Seconds
Default	2592000 (30 days)

settings:
  freezing_threshold: 7776000  # 90 days

The canister freezes if its cycles balance would be exhausted within this threshold.

reserved_cycles_limit

Maximum cycles the canister can hold in reserve.

Property	Value
Type	Integer
Unit	Cycles
Default	No limit

settings:
  reserved_cycles_limit: 1000000000000  # 1T cycles

wasm_memory_limit

Maximum heap size for the WASM module.

Property	Value
Type	Integer
Unit	Bytes
Default	Platform default

settings:
  wasm_memory_limit: 1073741824  # 1GB

wasm_memory_threshold

Memory threshold that triggers low-memory callbacks.

Property	Value
Type	Integer
Unit	Bytes
Default	None

settings:
  wasm_memory_threshold: 536870912  # 512MB

log_visibility

Controls who can read canister logs.

Property	Value
Type	String or Object
Values	`controllers`, `public`, or `allowed_viewers` object
Default	`controllers`

# Only controllers can view logs (default)
settings:
  log_visibility: controllers

# Anyone can view logs
settings:
  log_visibility: public

# Specific principals can view logs
settings:
  log_visibility:
    allowed_viewers:
      - "aaaaa-aa"
      - "2vxsx-fae"

environment_variables

Runtime environment variables accessible to the canister.

Property	Value
Type	Object (string keys, string values)
Default	None

settings:
  environment_variables:
    API_URL: "https://api.example.com"
    DEBUG: "false"
    FEATURE_FLAGS: "advanced=true"

Environment variables allow the same WASM to run with different configurations.

Full Example

canisters:
  - name: backend
    build:
      steps:
        - type: script
          commands:
            - cargo build --target wasm32-unknown-unknown --release
            - cp target/wasm32-unknown-unknown/release/backend.wasm "$ICP_WASM_OUTPUT_PATH"
    settings:
      compute_allocation: 5
      memory_allocation: 2147483648       # 2GB
      freezing_threshold: 2592000         # 30 days
      reserved_cycles_limit: 5000000000000
      wasm_memory_limit: 1073741824       # 1GB
      wasm_memory_threshold: 536870912    # 512MB
      log_visibility: controllers
      environment_variables:
        ENV: "production"
        API_BASE_URL: "https://api.example.com"

Environment Overrides

Override settings per environment:

canisters:
  - name: backend
    settings:
      compute_allocation: 1  # Default

environments:
  - name: production
    network: mainnet
    canisters: [backend]
    settings:
      backend:
        compute_allocation: 20              # Production override
        freezing_threshold: 7776000         # 90 days
        environment_variables:
          ENV: "production"

CLI Commands

View settings:

icp canister settings show my-canister

Update settings:

icp canister settings update my-canister --compute-allocation 10

Sync settings from configuration:

icp canister settings sync my-canister