AWS SSM Parameter Store

Setup

Prerequisites

• AWS account with SSM Parameter Store access
• AWS credentials configured (env vars, ~/.aws/credentials, IAM roles, or SSO)

IAM Policy

Minimum required permissions:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "ssm:GetParameter",
        "ssm:GetParametersByPath",
        "ssm:PutParameter",
        "ssm:DeleteParameter"
      ],
      "Resource": "arn:aws:ssm:*:*:parameter/myapp/*"
    },
    {
      "Effect": "Allow",
      "Action": ["kms:Decrypt", "kms:Encrypt"],
      "Resource": "arn:aws:kms:*:*:key/*"
    }
  ]
}

Configuration

environments:
  prod:
    provider: aws
    path: /myapp/prod
    region: us-east-1
    profile: production    # Uses named profile from ~/.aws/credentials
    kms_key_id: arn:aws:kms:us-east-1:123456789:key/abc-def  # Optional

Usage

# Set a secret (stored as SecureString)
skret set /myapp/prod/DATABASE_URL "postgres://prod-host/db"

# Get a secret (auto-decrypts)
skret get /myapp/prod/DATABASE_URL

# List all secrets under path
skret list

# Run with injected env vars (path prefix stripped)
skret run -- node server.js
# DATABASE_URL=postgres://prod-host/db is injected

Quotas

skret only ever writes AWS SSM Standard-tier parameters — it never sets Tier: Advanced on PutParameter, so the effective value-size limit through skret is the Standard-tier cap, regardless of what your AWS account otherwise supports.

Resource	Limit
Parameter value size (via skret)	4 KB (Standard tier only; skret does not request Advanced)
Parameters per account/region	10,000 (standard)
GetParametersByPath throughput	40 TPS

A value over 4 KB fails with AWS’s ValidationException, surfaced as a provider error (skret exit code 3) — see error codes. If you need larger values, use the local provider for development, or a provider with a bigger cap (see provider comparison).

Security

• All parameter values are stored as SecureString (encrypted with KMS)
• Decryption happens at read time, never cached to disk
• IAM policies control access per path prefix