agentlyhq/summarize-whatsapp-group-chats

Summarize WhatsApp Group Chats

Use the wacli CLI to fetch and summarize WhatsApp group chats. No exceptions — always use wacli.

Prerequisites

• wacli is already installed and authenticated on the user's machine
• If wacli commands fail with auth errors, ask the user to re-authenticate before proceeding

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Step 1: Discover Available Group Chats

Before fetching messages, list available group chats to find the correct chat name or ID:

wacli groups list

If the user has specified a chat name, fuzzy-match it against the output. Confirm with the user if ambiguous, especially with similar group names.

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Step 2: Fetch Messages

Default behavior: fetch the past 24 hours. Adjust if the user specifies a different time range.

# Fetch last 24 hours (default) (please update YYYY-MM-DD below for --after and --before in RFC3339 format)
wacli messages list --chat "<chat-id>" --after "<YYYY-MM-DD HH:MM:SS of one day before today's date>" --before "<YYYY-MM-DD HH:MM:SS of today's date>"

# Fetch by specific date range (if user requests) in RFC3339 format
wacli messages list --chat "<chat-id>" --after "YYYY-MM-DD HH:MM:SS" --before "YYYY-MM-DD HH:MM:SS"

# Fetch by message count (if user requests)
wacli messages list --chat "<chat-id>" --limit 200

Capture the raw output. Note the timestamp of the oldest and newest message in the fetched data — this becomes the data freshness marker.

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Step 3: Export (Optional but Default)

By default, export the raw chat to a .json file before summarizing. Filename format:

[chat-name]-YYYYMMDD.txt

• Use today's date
• Sanitize the chat name: lowercase, replace spaces with hyphens, strip special characters
• Example: product-team-20250315.txt

wacli messages --chat "<chat-id>" --after "<YYYY-MM-DD of one day before today's date>" --before "<YYYY-MM-DD of today's date>" > "[chat-name]-YYYYMMDD.txt"

If the user specifies a different filename or path, use that instead.

If user prefers JSON, follow that by adding global --json flag the above wacli command.

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Step 4: Summarize — Chief of Staff Style

Summarize the fetched messages. Write like a chief of staff briefing an executive: concise, structured, action-oriented. No padding, no filler.

Summary Format

## [Chat Name] — Summary
**Data covers:** [oldest message timestamp] → [newest message timestamp]
**Fetched at:** [current timestamp]

### Key Decisions
- ...

### Action Items
- [Person] — [what they need to do]

### Notable Discussions
- ...

### FYI / Context
- ...

Only include sections that have content. Skip empty sections entirely.

Summarization Rules

• Never hallucinate. Every point must come directly from the fetched messages.
• Do not invent names, facts, decisions, or action items. If something is unclear, say so.
• Be brief. Aim for signal density — one tight sentence per point.
• Attribute where it matters. For decisions and action items, note who said or owns what.
• Flag urgency. If something is time-sensitive or unresolved, note it explicitly.
• Ignore noise. Skip greetings, reactions, one-word replies, and off-topic banter unless they reveal something important.

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Step 5: Handle User Overrides

The user may ask for changes. Always comply. Common overrides:

| User Request | What to Do | |---|---| | Different time range | Re-fetch with --since / --until adjusted | | Different language | Summarize in the requested language | | More detail on a topic | Expand that section, pull specific messages | | Different filename | Rename the export file | | Skip export | Don't write the .txt file | | Longer / shorter summary | Adjust verbosity accordingly | | Specific people only | Filter messages by sender in summary |

Whatever the user asks — as long as it's achievable via wacli and summarization — do it.

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Error Handling

| Error | Response | |---|---| | wacli not found | Tell user to install and authenticate wacli first | | Auth failure | Ask user to re-run wacli auth or equivalent | | Chat not found | List available chats with wacli chats and ask user to confirm | | No messages in range | Say so clearly; offer to widen the time range | | Empty output | Do not summarize. Report that no messages were found. |

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Quick Reference: wacli Commands

Usage:
  wacli messages [command]

Available Commands:
  context     Show message context around a message ID
  list        List messages
  search      Search messages (FTS5 if available; otherwise LIKE)
  show        Show one message

Flags:
  -h, --help   help for messages

Global Flags:
      --json               output JSON instead of human-readable text
      --store string       store directory (default: ~/.wacli)
      --timeout duration   command timeout (non-sync commands) (default 5m0s)

wacli chats                          # List all chats
wacli messages list --chat "<chat-id>" --after "<YYYY-MM-DD of one day before today's date>" --before "<YYYY-MM-DD of today's date>" # Fetch last 24 hours (default) (please update YYYY-MM-DD below for --after and --before)

If wacli has different flags on the user's version, run wacli --help or wacli messages --help to check and adapt.