/add-rule

Add Rule

Adds a new rule to an existing SYNAPSE domain file.

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Purpose

Append a new rule to a domain file in `.synapse/`, auto-incrementing the rule index to maintain a valid KEY=VALUE sequence.

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Prerequisites

• `.synapse/manifest` exists
• Target domain exists in manifest AND as a file in `.synapse/`

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Parameters

| Parameter | Required | Description | |-----------|----------|-------------| | `domain-name` | Yes | Existing domain name (kebab-case) | | `rule-text` | Yes | The rule text to add |

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Steps

Step 1: Validate Domain Exists

1. Derive the domain key: `my-domain` -> `MY_DOMAIN` 2. Read `.synapse/manifest` and check that `{DOMAIN_KEY}_STATE` exists 3. Check that `.synapse/{domain-name}` file exists on disk

If domain not found in manifest: `Error: Domain "{domain-name}" not found in manifest. Use "create" to create it first.`

If domain file not found: `Error: Domain file ".synapse/{domain-name}" not found on disk. Manifest entry exists but file is missing.`

Step 2: Find Next Rule Index

Read the domain file `.synapse/{domain-name}` and find all existing rules matching the pattern `{DOMAIN_KEY}_RULE_{N}=`.

Count the number of matching rules. The new rule index is `count(matching_rules)`.

This ensures sequential indices with no gaps (e.g., if rules 0 and 2 exist but 1 was deleted, there are 2 rules, so the next index is 2 — which re-fills gaps).

If no rules exist yet, start at `0`.

Step 3: Append Rule

Append the new rule line to the domain file:

{DOMAIN_KEY}_RULE_{NEXT_INDEX}={rule-text}

Ensure there is a newline before the new rule if the file does not end with one.

Step 4: Confirm

Display confirmation:

Added rule to {domain-name}:
  {DOMAIN_KEY}_RULE_{NEXT_INDEX}={rule-text}

Domain now has {TOTAL} rules.

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Validation

• [ ] Domain exists in both manifest and filesystem before adding
• [ ] Rule index auto-incremented correctly (no gaps, no duplicates)
• [ ] Rule line follows `{DOMAIN_KEY}_RULE_{N}=text` format
• [ ] Domain file remains parseable after addition

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Error Handling

| Error | Message | |-------|---------| | Domain not in manifest | `Error: Domain "{name}" not found in manifest. Use "create" to create it first.` | | Domain file missing | `Error: Domain file ".synapse/{name}" not found on disk.` | | Empty rule text | `Error: Rule text cannot be empty.` | | Manifest not found | `Error: .synapse/manifest not found. SYNAPSE must be initialized first.` |

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*Add Rule — SYNAPSE CRUD Command C3* *Source: SYNAPSE-HOOK-SKILL-COMMAND-ANALYSIS.md section 2.3*