Verifying Assumptions

Executable Verification

Core rule: Every assumption must be verified by writing a script file and executing it.

The Pattern

1. Identify assumption → 2. Write script FILE → 3. Execute file → 4. Act on result

Critical: "Write a script" means creating an actual file on disk, then running that file. Never execute verification logic inline.

Minimum per task: Write and run at least one precondition script file (before acting) AND one postcondition script file (after acting).

Script Examples

Correct workflow: Write file → Execute file

# 1. Write the script to a file
cat > verification/check-config.sh  "$VERIFY_SESSION/check-port.sh" << 'EOF'
#!/bin/bash
nc -z localhost 3000 && echo "PASS: port 3000 open" || { echo "FAIL: port 3000 closed"; exit 1; }
EOF
bash "$VERIFY_SESSION/check-port.sh"

Multi-Step Tasks

Never chain actions without intermediate verification scripts:

Step 1: [write & run pre-script] → act → [write & run post-script]
                                                    ↓
Step 2: [write & run pre-script] → act → [write & run post-script]

Each step's postconditions become the next step's preconditions. Verify them with script files, not inline commands.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: andrueandersoncs
• Source: andrueandersoncs/claude-skill-executable-verification
• License: MIT

Install and usage instructions live in the source repository linked above.