Context-as-a-Service: Surfacing Cross-File Dependency Chains for LLM-Generated Developer Documentation
Summary
Context-as-a-Service (CaaS) is a retrieval layer that LLM agents query to find evidence across the codebase as they review or generate documentation. CaaS indexes source code, API references, and upstream documentation, enabling agents to query the index through tool calls combining keyword and semantic search. Evaluated using Claude Sonnet 4.6 on a production SDK with approximately 200 source files, CaaS-augmented agents surfaced 8 additional findings (2 cross-file factual errors, 2 underspecified API comments, 1 executable bug, 1 API-usage improvement, and 2 missing prerequisites) that baseline agents with ordinary repository tools missed. These findings required tracing non-obvious dependency chains across various file types. Furthermore, adding CaaS reduced wall-clock time by 22% to 34% across two tasks and lowered input-token usage over five runs per condition.
Key takeaway
For AI Engineers or ML Scientists developing LLM agents for code documentation, integrating a retrieval layer like CaaS is crucial. Your agents can generate locally plausible but globally incorrect documentation without it, missing critical cross-file dependencies. Implement a retrieval-augmented generation (RAG) system to index diverse codebase elements, enabling agents to proactively identify and correct subtle errors, thereby improving documentation accuracy and reducing review time.
Key insights
CaaS enhances LLM documentation agents by surfacing non-obvious cross-file dependencies, improving accuracy and efficiency.
Principles
- Documentation claims often depend on behavior distributed across files.
- Locally plausible documentation can be globally incorrect.
- Retrieval augments an agent's exploration, it does not replace file inspection.
Method
CaaS employs a four-stage pipeline: ingestion (source code, API references, upstream documentation), storage (BM25 and DRAMA indexing), retrieval (tool-callable interface combining BM25 and DRAMA results), and a review layer for labeling findings.
In practice
- Index diverse source types: code, API references, tests, examples.
- Combine keyword and dense search for robust retrieval.
- Guide agent exploration with compact, pre-ranked snippets.
Topics
- LLM Agents
- Developer Documentation
- Retrieval-Augmented Generation
- Cross-File Dependencies
- Codebase Indexing
- Semantic Search
Best for: AI Architect, Research Scientist, AI Scientist, Machine Learning Engineer, AI Engineer
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Editorial summary, takeaway, and curation by AIssential. Original article published by cs.SE updates on arXiv.org.