When users need to understand code across internal repositories—beyond the local codebase—use Glean's code search to explore the entire organization's code.
Tool Naming
See the glean-tools-guide skill for Glean MCP tool naming conventions. Tools follow the pattern mcp__glean_[server-name]__[tool] where the server name is dynamic.
When This Applies
Use Glean code search when users ask about:
- How something is implemented (in other repos)
- Where the code for a system/service lives
- Who has been working on a codebase
- Similar implementations across the org
- Examples of how to use an internal API/library
- Code patterns used by other teams
BE SKEPTICAL
Not every code result is worth presenting.
Quality Test
- Is this good code to reference?
- ✅ GOOD: Clean, tested, actively maintained
- ⚠️ ACCEPTABLE: Works but has caveats
- ❌ POOR: Hacky, deprecated, abandoned
Recency Test
- Is this code maintained?
- ✅ ACTIVE: Commits in past 3 months
- ⚠️ SLOWING: 3-12 months since last commit
- ❌ STALE: 12+ months - likely outdated patterns
Relevance Test
- Does this actually answer the question?
- ✅ RELEVANT: Directly addresses what was asked
- ⚠️ RELATED: Similar but different context
- ❌ TANGENTIAL: Keyword match only
Filter Out:
- Code in
/deprecated/,/old/,/legacy/paths - Abandoned repositories
- Prototype/experimental code
- Code with extensive TODO/FIXME comments
Quality over quantity: 3 good examples beat 10 mediocre ones.
Key Differentiator
Local tools (grep, glob) search only the current repo. Glean searches across ALL repositories in the organization. This is powerful for:
- Finding examples: "How do other teams handle authentication?"
- Understanding systems: "What repos touch the billing service?"
- Finding owners: "Who's been active in the payments codebase?"
Tool Selection
| User Intent | Glean Tool |
|---|---|
| Find code by content, pattern, or file | code_search |
| Find related design docs or specs | search |
| Identify code owners/contributors | code_search + employee_search |
| Read full file content | read_document |
Query Patterns
Glean's code search understands natural language. Use filters for precision:
# Search by content
code_search "authentication middleware"
code_search "rate limiting implementation"
# Search by contributor
code_search "owner:\"John Smith\" billing service"
code_search "from:me updated:past_week"
# Search by time
code_search "after:2024-01-01 payments API"
# Search by file pattern
code_search "*.proto user service"
Workflow: Exploring a System
- Find the code:
code_search "[system name]" - Vet results: Filter for quality and recency
- Find the docs:
search "[system name] design doc OR architecture" - Find the people:
code_search "owner:* [system] updated:past_month" - Read details:
read_documentwith URLs from vetted results
If No Good Code Found
Don't pad with weak results:
No high-quality code examples found for [topic].
**What was searched:**
- [Queries attempted]
**What was filtered:**
- [X] matches - [reasons: outdated/poor quality]
**Suggestions:**
- Check external libraries
- Ask in [relevant channel]
- This may need to be built from scratch
Relationship to Commands
For structured workflows, suggest the relevant slash command:
/glean-code:codebase-context [system]- Get comprehensive context/glean-code:find-examples [API/pattern]- Find usage examples/glean-code:code-owners [component]- Identify maintainers/glean-code:similar-code [pattern]- Find similar implementations