Slack Directory Lookup

Why This Skill Exists

The Problem:
When someone says "DM Sarah about the budget" or "add Mike to the channel," you need a Slack user ID — not a name. Slack's API requires IDs for all user operations, but humans think in names.

The Solution:
This skill lets you search Slack users by partial name (first, last, display name, or username), handles multiple matches gracefully, and builds a local cache so you never look up the same person twice.

Real-world example:

"Hey, message the new hire about onboarding"
→ "What's their name?"
→ "Jamie something... started last week"
→ Run lookup for "Jamie" → Find Jamie Chen (U09ABC123)
→ Cache the mapping → Send the message

When to Use This Skill

How It Works

Step 1: Check Your Cache First

Before calling the API, check if you already have the mapping cached (in TOOLS.md, a JSON file, or wherever you store local state):

### People Directory
| Name | Slack ID | Notes |
|------|----------|-------|
| Sarah Chen | U09ABC123 | Engineering |
| Mike Brown | U07XYZ789 | Sales lead |

Why cache? Slack API calls cost time and rate limits. Most workspaces have the same 20-50 people you interact with regularly. Cache them once, use forever.

Step 2: Fuzzy Search via API

If not cached, run the lookup:

./lookup.sh "jamie"

The script searches across:

• real_name (e.g., "Jamie Chen")
• display_name (e.g., "Jamie C")
• username (e.g., "jamie.chen")

Case-insensitive, partial match.

Step 3: Handle Results

Single match → Use it and cache it:

✅ Single match found:
| Jamie Chen | U09ABC123 | jamie.chen@company.com |

Multiple matches → Clarify with the user:

⚠️ Multiple matches for 'jamie' (2 found):
1. Jamie Chen (U09ABC123) - jamie.chen@company.com
2. Jamie Rodriguez (U08DEF456) - jamie.r@company.com

Which one did you mean?

No matches → Help troubleshoot:

❌ No matches found for 'jamie'

Suggestions:
- Check spelling
- Try first or last name only
- They may not be in this workspace

Step 4: Update Cache

After finding someone new, add them to your local cache for next time.

Setup

Requirements

1. Slack Bot Token with users:read scope
2. jq installed for JSON parsing
3. curl for API calls

Getting Your Bot Token

If your agent platform already manages Slack tokens for you, the token may already be available. Otherwise:

1. Create a Slack App at api.slack.com/apps
2. Add Bot Token Scopes: users:read, users:read.email (optional)
3. Install to workspace
4. Copy the Bot User OAuth Token (xoxb-...)

Token Storage Options

The included lookup.sh expects the token in an environment variable or secrets manager. Edit the TOKEN CONFIGURATION block near the top of the script for your setup:

# Option 1: Environment variable
TOKEN="${SLACK_BOT_TOKEN}"

# Option 2: GCP Secret Manager
TOKEN=$(gcloud secrets versions access latest --secret="slack-bot-token" --project=YOUR_PROJECT)

# Option 3: AWS Secrets Manager  
TOKEN=$(aws secretsmanager get-secret-value --secret-id slack-bot-token --query SecretString --output text)

# Option 4: File (less secure, but simple)
TOKEN=$(cat ~/.slack-token)

API Details

Endpoint: https://slack.com/api/users.list
Auth: Authorization: Bearer xoxb-...
Rate limit: Tier 2 (~20 requests/minute) — safe for occasional lookups

Useful User Object Fields

Manual API Call (if script unavailable)

TOKEN="xoxb-your-token"

# List all active users
curl -s -H "Authorization: Bearer $TOKEN" \
  "https://slack.com/api/users.list" | \
  jq '.members[] | select(.deleted == false and .is_bot == false) | {id, name, real_name}'

# Filter for a name
curl -s -H "Authorization: Bearer $TOKEN" \
  "https://slack.com/api/users.list" | \
  jq --arg q "jamie" '.members[] | select(.deleted == false) | select((.real_name // "" | ascii_downcase | contains($q)))'

Common Patterns

"DM [name] about [topic]"

1. Check cache for name
2. If not found → Run lookup
3. If single match → Cache it, send DM
4. If multiple → Ask "Which [name]?"
5. If none → Ask for clarification

"Add [name] to #channel"

Same flow, then use the ID with conversations.invite

"Who is [name]?"

Run lookup, display full profile info (name, email, title if available)

Building Initial Directory

For new workspaces, you can bulk-cache everyone:

curl -s -H "Authorization: Bearer $TOKEN" \
  "https://slack.com/api/users.list" | \
  jq -r '.members[] | select(.deleted == false and .is_bot == false) | "| \(.real_name) | \(.id) | |"'

This outputs a markdown table you can paste into your cache file.

Why This Belongs in Tier 2 (Communication)

This skill is foundational to Slack communication:

• Tier 1 is infrastructure (secrets, auth, basic setup)
• Tier 2 is communication (email, calendar, Slack, messaging)
• Tier 3+ is business operations

If your agent uses Slack, it will eventually need to look up users. This skill solves that cleanly, with caching to make it fast and reliable over time.

Files Included

slack-directory/
├── SKILL.md      # This documentation
└── lookup.sh     # Bash script for fuzzy user search