|
1 | | -# Language Server Agent Protocol (LSAP) |
| 1 | +# LSAP: Language Server Agent Protocol |
| 2 | + |
| 3 | +[](LICENSE) |
| 4 | +[]() |
| 5 | + |
| 6 | +**LSAP (Language Server Agent Protocol)** transforms low-level LSP capabilities into high-level, **Agent-Native** cognitive tools, empowering Coding Agents with **Repository-Scale Intelligence**. |
| 7 | + |
| 8 | +As an **Orchestration Layer**, LSAP composes atomic LSP operations into semantic interfaces. This aligns with Agent cognitive logic, allowing them to focus on high-level "intent realization" rather than tedious "editor operations." |
| 9 | + |
| 10 | +## Core Concept: Atomic Capabilities vs. Cognitive Capabilities |
| 11 | + |
| 12 | +The core difference of LSAP lies in how it defines "capabilities." LSP is designed for editors, providing **Atomic** operations; whereas LSAP is designed for Agents, providing **Cognitive** capabilities. |
| 13 | + |
| 14 | +- **LSP (Editor Perspective - Atomic)**: |
| 15 | + - Editors require very low-level instructions: `textDocument/definition` (jump), `textDocument/hover` (hover), `textDocument/documentSymbol` (outline). |
| 16 | + - **The Agent's Dilemma**: If an Agent uses LSP directly, it needs to execute a dozen interactions sequentially like a script (open file -> calculate offset -> request definition -> parse URI -> read file -> extract snippet) just to get a useful context. |
| 17 | +- **LSAP (Agent Perspective - Cognitive)**: |
| 18 | + - LSAP encapsulates the complex chain of atomic operations above into a single semantic instruction. |
| 19 | + - **Example**: A single request to "Find all references" triggers background execution of symbol localization, reference search, and context extraction, returning a consolidated **Markdown Report**. |
| 20 | + |
| 21 | +```mermaid |
| 22 | +sequenceDiagram |
| 23 | + participant Agent as 🤖 Agent |
| 24 | + participant LSAP as 🧠 LSAP Layer |
| 25 | + participant LSP as 🔧 Language Server |
| 26 | +
|
| 27 | + Note left of Agent: Goal: Find all references of "User" |
| 28 | +
|
| 29 | + Agent->>LSAP: 1. Semantic Request (Locate + References) |
| 30 | +
|
| 31 | + rect rgb(245, 245, 245) |
| 32 | + Note right of LSAP: ⚡️ Auto Orchestration |
| 33 | + LSAP->>LSAP: Parse Semantic Anchor (Fuzzy Match) |
| 34 | + LSAP->>LSP: textDocument/hover (Confirm Symbol Info) |
| 35 | + LSAP->>LSP: textDocument/references (Get Reference List) |
| 36 | + LSP-->>LSAP: Return List<Location> |
| 37 | +
|
| 38 | + loop For each reference point |
| 39 | + LSAP->>LSP: textDocument/documentSymbol (Identify Function/Class) |
| 40 | + LSAP->>LSAP: Read Surrounding Code (Context Lines) |
| 41 | + end |
| 42 | + end |
| 43 | +
|
| 44 | + LSAP-->>Agent: 2. Structured Markdown (Callers + Code Context) |
| 45 | +``` |
| 46 | + |
| 47 | +## Interaction Example |
| 48 | + |
| 49 | +LSAP's interaction design strictly follows the **Markdown-First** principle: input expresses intent, and output provides refined knowledge. |
| 50 | + |
| 51 | +### Request: Semantic Search (Demonstrating Composed Capabilities) |
| 52 | + |
| 53 | +The Agent only needs to issue a high-level command without worrying about underlying row/column calculations or file reading: |
| 54 | + |
| 55 | +```jsonc |
| 56 | +// Intent: Find all usages of 'format_date' to refactor it |
| 57 | +{ |
| 58 | + "locate": { |
| 59 | + "file_path": "src/utils.py", |
| 60 | + "find": "def format_date<|>", // Semantic Anchor |
| 61 | + }, |
| 62 | + "mode": "references", |
| 63 | + "max_items": 10, |
| 64 | +} |
| 65 | +``` |
| 66 | + |
| 67 | +### Response: Structured Knowledge |
| 68 | + |
| 69 | +LSAP aggregates the results of `references` (locations), `documentSymbol` (caller context), and `read` (code snippets): |
| 70 | + |
| 71 | +````markdown |
| 72 | +# References Found |
| 73 | + |
| 74 | +Total references: 45 | Showing: 2 |
| 75 | + |
| 76 | +### `src/ui/header.py`:28 |
| 77 | + |
| 78 | +In `Header.render` (`Method`) |
| 79 | + |
| 80 | +```python |
| 81 | +formatted = format_date(user.last_login) |
| 82 | +``` |
| 83 | + |
| 84 | +### `src/api/views.py`:42 |
| 85 | + |
| 86 | +In `UserDetail.get` (`Method`) |
| 87 | + |
| 88 | +```python |
| 89 | +return {"date": format_date(obj.created_at)} |
| 90 | +``` |
| 91 | +```` |
| 92 | + |
| 93 | +## I'm Not Convinced... |
| 94 | + |
| 95 | +### "LSAP Just Replicates LSP—What's Special?" |
| 96 | + |
| 97 | +While LSP provides **atomic operations**, LSAP offers **composed capabilities**. |
| 98 | + |
| 99 | +For instance, the **[Relation API](docs/schemas/draft/relation.md)** finds call paths between functions in a single request (handling traversal, cycles, and formatting), a task requiring complex orchestration in raw LSP. Similarly, the **[Unified Hierarchy API](docs/schemas/draft/hierarchy.md)** delivers unified graph representations optimized for agents. |
| 100 | + |
| 101 | +LSAP centralizes these patterns, preventing agents from wasting tokens on orchestration and enabling advanced capabilities like architectural and impact analysis. |
| 102 | + |
| 103 | +### "This Adds Complexity" |
| 104 | + |
| 105 | +LSAP **centralizes** complexity. Instead of every Agent reimplementing LSP orchestration logic, LSAP provides a shared, optimized layer for these common patterns. |
| 106 | + |
| 107 | +## Project Structure |
| 108 | + |
| 109 | +- [`docs/`](docs/): Core protocol definitions and Schema documentation. |
| 110 | +- [`python/`](python/): Python SDK reference implementation. |
| 111 | +- [`typescript/`](typescript/): TypeScript type definitions and utility library. |
| 112 | +- [`web/`](web/): Protocol documentation site. |
| 113 | + |
| 114 | +## Alternatives |
| 115 | + |
| 116 | +- Claude Code have native LSP supports now. |
| 117 | +- [claude-code-lsps](https://github.com/Piebald-AI/claude-code-lsps) |
| 118 | +- [serena](https://github.com/oraios/serena) |
| 119 | +- [cclsp](https://github.com/ktnyt/cclsp) |
| 120 | +- [mcpls](https://github.com/bug-ops/mcpls) |
| 121 | + |
| 122 | +## Contributing |
| 123 | + |
| 124 | +We welcome contributions! Please see our [Contributing Guide](CONTRIBUTING.md) for details on development workflows and design principles. |
| 125 | + |
| 126 | +## License |
| 127 | + |
| 128 | +[MIT](LICENSE) |
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