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hematite/agent/
prompt.rs

1use std::fs;
2use std::path::PathBuf;
3
4use crate::agent::git;
5
6enum WorkspaceMode {
7    Coding,
8    Document,
9    General,
10}
11
12fn detect_workspace_mode(root: &PathBuf) -> WorkspaceMode {
13    // Strong coding signals — any of these present means it's a coding workspace
14    let coding_markers = [
15        "Cargo.toml",
16        "package.json",
17        "pyproject.toml",
18        "setup.py",
19        "go.mod",
20        "pom.xml",
21        "build.gradle",
22        "CMakeLists.txt",
23        ".git",
24        "src",
25        "lib",
26    ];
27    for marker in &coding_markers {
28        if root.join(marker).exists() {
29            return WorkspaceMode::Coding;
30        }
31    }
32
33    // No strong coding signal — check file extensions
34    let code_exts = [
35        "rs", "py", "ts", "js", "go", "cpp", "c", "java", "cs", "rb", "swift", "kt",
36    ];
37    let doc_exts = ["pdf", "md", "txt", "docx", "epub", "rst"];
38    let mut code_count = 0usize;
39    let mut doc_count = 0usize;
40
41    if let Ok(entries) = fs::read_dir(root) {
42        for entry in entries.flatten() {
43            let path = entry.path();
44            if path.is_file() {
45                if let Some(ext) = path.extension().and_then(|e| e.to_str()) {
46                    let ext = ext.to_lowercase();
47                    if code_exts.contains(&ext.as_str()) {
48                        code_count += 1;
49                    }
50                    if doc_exts.contains(&ext.as_str()) {
51                        doc_count += 1;
52                    }
53                }
54            }
55        }
56    }
57
58    if code_count > 0 {
59        WorkspaceMode::Coding
60    } else if doc_count > 0 {
61        WorkspaceMode::Document
62    } else {
63        WorkspaceMode::General
64    }
65}
66
67pub struct SystemPromptBuilder {
68    pub workspace_root: PathBuf,
69}
70
71impl SystemPromptBuilder {
72    pub fn new(root: PathBuf) -> Self {
73        Self {
74            workspace_root: root,
75        }
76    }
77
78    /// Build the full system prompt with Rule Hierarchy and Gemma-4 Optimization.
79    /// Hierarchy: Global ($HOME) -> Project (Root) -> Local (Ignored).
80    pub fn build(
81        &self,
82        base_instructions: &str,
83        memory: Option<&str>,
84        summary: Option<&str>,
85        mcp_tools: &[crate::agent::mcp::McpTool],
86    ) -> String {
87        let config = crate::agent::config::load_config();
88        let mut static_sections = Vec::new();
89
90        let workspace_framing = match detect_workspace_mode(&self.workspace_root) {
91            WorkspaceMode::Coding => "You are Hematite, a local AI coding agent running on the user's machine. \
92                             Hematite is more than the terminal UI: it is the full local harness for tool use, code editing, context management, voice, and orchestration. \
93                             The current directory is a software project — lean into code editing, build verification, and repo-aware tooling.",
94            WorkspaceMode::Document => "You are Hematite, a local AI assistant running on the user's machine. \
95                             Hematite is more than the terminal UI: it is the full local harness for tool use, file analysis, context management, voice, and orchestration. \
96                             The current directory contains documents and files — lean into reading, summarizing, explaining, and answering questions about the content here.",
97            WorkspaceMode::General => "You are Hematite, a local AI assistant running on the user's machine. \
98                             Hematite is more than the terminal UI: it is the full local harness for tool use, file operations, context management, voice, and orchestration.",
99        };
100
101        static_sections.push("# IDENTITY & TONE".to_string());
102        static_sections.push(format!("{} \
103                             Be direct, practical, technically precise, and ASCII-first in ordinary prose. \
104                             For simple questions, answer briefly in plain language. \
105                             Do not expose internal tool names, hidden protocols, or planning jargon unless the user asks.", workspace_framing));
106        static_sections.push(format!(
107            "- Running Hematite build: {}",
108            crate::hematite_version_display()
109        ));
110
111        static_sections.push(format!("\n# BASE INSTRUCTIONS\n{base_instructions}"));
112
113        if let Some(home) = std::env::var_os("USERPROFILE") {
114            let global_path = PathBuf::from(home).join(".hematite").join("CLAUDE.md");
115            if global_path.exists() {
116                if let Ok(content) = fs::read_to_string(&global_path) {
117                    static_sections.push(format!("\n# GLOBAL USER PREFERENCES\n{content}"));
118                }
119            }
120        }
121
122        for name in &["CLAUDE.md", ".claude.md", "CLAUDE.local.md"] {
123            let path = self.workspace_root.join(name);
124            if path.exists() {
125                if let Ok(content) = fs::read_to_string(&path) {
126                    let content = if content.len() > 6000 {
127                        format!("{}...[Rules Truncated]", &content[..6000])
128                    } else {
129                        content
130                    };
131                    static_sections.push(format!("\n# PROJECT RULES ({})\n{}", name, content));
132                }
133            }
134        }
135
136        let instructions_dir = self.workspace_root.join(".hematite").join("instructions");
137        if instructions_dir.exists() && instructions_dir.is_dir() {
138            if let Ok(entries) = fs::read_dir(instructions_dir) {
139                for entry in entries.flatten() {
140                    let path = entry.path();
141                    if path.extension().map(|e| e == "md").unwrap_or(false) {
142                        let stem = path.file_stem().and_then(|s| s.to_str()).unwrap_or("");
143                        let include = if let Some(mem) = memory {
144                            mem.to_lowercase().contains(&stem.to_lowercase())
145                        } else {
146                            false
147                        };
148
149                        if include {
150                            if let Ok(content) = fs::read_to_string(&path) {
151                                static_sections.push(format!(
152                                    "\n# DEEP CONTEXT RULES ({}.md)\n{}",
153                                    stem, content
154                                ));
155                            }
156                        }
157                    }
158                }
159            }
160        }
161
162        let mut prompt = static_sections.join("\n");
163        prompt.push_str(
164            "\n\n###############################################################################\n",
165        );
166        prompt.push_str(
167            "# DYNAMIC CONTEXT (Changes every turn)                                        #\n",
168        );
169        prompt.push_str(
170            "###############################################################################\n",
171        );
172
173        if let Some(s) = summary {
174            prompt.push_str(&format!(
175                "\n# COMPACTED HISTORY SUMMARY\n{}\nRecent messages are preserved below.",
176                s
177            ));
178        }
179
180        if let Some(mem) = memory {
181            prompt.push_str(&format!("\n# SESSION MEMORY\n{mem}"));
182        }
183
184        prompt.push_str("\n# ENVIRONMENT");
185        prompt.push_str(&format!(
186            "\n- Local Time: {}",
187            chrono::Local::now().format("%Y-%m-%d %H:%M:%S")
188        ));
189        prompt.push_str(&format!(
190            "\n- Hematite Build: {}",
191            crate::hematite_version_display()
192        ));
193        prompt.push_str("\n- Operating System: Windows (User workspace)");
194
195        if git::is_git_repo(&self.workspace_root) {
196            if let Ok(branch) = git::get_active_branch(&self.workspace_root) {
197                prompt.push_str(&format!("\n- Git Branch: {branch}"));
198            }
199        }
200
201        let hematite_dir = self.workspace_root.join(".hematite");
202        for (name, path) in [
203            ("TASK", hematite_dir.join("TASK.md")),
204            ("PLAN", hematite_dir.join("PLAN.md")),
205        ] {
206            if path.exists() {
207                if let Ok(content) = fs::read_to_string(&path) {
208                    if !content.trim().is_empty() {
209                        let content = if content.len() > 3000 {
210                            format!("{}...[Truncated]", &content[..3000])
211                        } else {
212                            content
213                        };
214                        prompt.push_str(&format!(
215                            "\n\n# ACTIVE TASK {} (.hematite/)\n{}",
216                            name, content
217                        ));
218                    }
219                }
220            }
221        }
222
223        if !mcp_tools.is_empty() {
224            prompt.push_str("\n\n# ACTIVE MCP TOOLS");
225            for tool in mcp_tools {
226                let mut description = tool
227                    .description
228                    .clone()
229                    .unwrap_or_else(|| "No description provided.".to_string());
230                if description.len() > 180 {
231                    description.truncate(180);
232                    description.push_str("...");
233                }
234                prompt.push_str(&format!("\n- {}: {}", tool.name, description));
235            }
236        }
237
238        if let Some(hint) = &config.context_hint {
239            prompt.push_str(&format!("\n## PROJECT CONTEXT HINT\n{}\n", hint));
240        }
241
242        prompt.push_str("\n## OPERATIONAL PROTOCOL (Gemma-4-E4B Native)\n");
243        prompt.push_str("1. **Thinking Mode**: ALWAYS use the thought channel (`<|channel>thought ... <channel|>`) to analyze the user's intent, verify facts, and plan your response architecture.\n");
244        prompt.push_str("2. **Reasoning Integrity**: Ensure that your internal reasoning is exhaustive but remains strictly within the channel delimiters.\n");
245        prompt.push_str("3. **Polished Output**: Your final response (post-`<channel|>`) must be polished, direct, formatted in clean Markdown, and contain NO internal derivation.\n");
246        prompt.push_str("4. **Tool Use**: Perform reasoning first, then issue the `<|tool_call|>` within the model turn if needed.\n");
247        prompt.push_str("5. **Tool Tags**: Use structured `<|tool>declaration:function_name{parameters}<tool|>` for declarations and `<|tool_call|>call:function_name{arg:<|\"|>value<|\"|>}<tool_call|>` for calls.\n");
248        prompt.push_str("6. **Safety**: String values MUST use the `<|\"|>` wrapper for safety.\n");
249        prompt.push_str("7. **Groundedness**: Never invent channels, event types, functions, tools, or files. If a detail is not verified from the repo or tool output, say `uncertain`.\n");
250        prompt.push_str("8. **Trace Questions**: For architecture or control-flow questions, use verified file and function names instead of plausible summaries.\n");
251        prompt.push_str("9. **Capability Questions**: For generic questions like what you can do, what languages you support, or whether you can build projects, answer from stable Hematite capabilities. Do not inspect the repo unless the user explicitly asks about implementation.\n");
252        prompt.push_str("10. **Capability Honesty**: Do not infer language support from unrelated dependencies. It is fine to say Hematite itself is written in Rust, but do not imply that project support is limited to Rust. Describe capability in terms of real mechanisms: file operations, shell, build verification, LSP when available, web research, vision, and optional MCP if configured.\n");
253        prompt.push_str("11. **Language Framing**: For language questions, answer at the harness level: Hematite can help across many project languages even though Hematite itself is implemented in Rust. Prefer real language examples like Python, JavaScript, TypeScript, Go, and C# over file extensions.\n");
254        prompt.push_str("12. **Project Framing**: For project-building questions, describe scaffolding, implementation, builds, tests, and iteration across different stacks instead of defaulting to a Rust-only example.\n");
255        prompt.push_str("13. **Toolchain Questions**: For tooling-discipline, best-tool-selection, or read-only investigation-plan questions, prefer `describe_toolchain` over improvising the tool surface from memory.\n");
256        prompt.push_str("14. **Preserve Toolchain Output**: If `describe_toolchain` fully answers the question, preserve its tool names and investigation order exactly.\n");
257        prompt.push_str("15. **Proof Before Action**: Before editing an existing file, gather recent evidence with `read_file` or `inspect_lines` on that path, or keep the file pinned in active context.\n");
258        prompt.push_str("16. **Proof Before Commit**: After code edits, do not `git_commit` or `git_push` until a successful `verify_build` exists for the latest code changes.\n");
259        prompt.push_str("17. **Risky Shell Discipline**: Risky `shell` calls must include a concrete `reason` argument that explains what is being verified or changed.\n");
260        prompt.push_str("18. **Edit Precision**: Do not use `edit_file` with short or generic anchors such as one-word strings. Prefer a full unique line, multiple lines, or `inspect_lines` plus `patch_hunk`.\n");
261        prompt.push_str("19. **Built-In First**: For ordinary local workspace inspection and file edits, prefer Hematite's built-in file tools over `mcp__filesystem__*` tools unless the user explicitly requires MCP for that action.\n");
262        prompt.push_str("20. **Deep Sync**: Every 6th turn, review the full TASK.md.\n\n21. **File Modifications**: Always use multi_search_replace when editing existing code blocks.\n");
263        prompt.push_str("22. **Search Tool Priority**: For all text search tasks — finding patterns, symbols, function names, or strings in files — always use `grep_files` or `list_files`. Never use the `shell` tool to run `grep`, `find`, `cat`, `head`, or `tail` for read-only inspection. Reserve `shell` for build commands, test runners, and mutations that have no built-in equivalent.");
264
265        prompt.push_str("23. **Host Inspection Priority**: For read-only questions about installed tools, PATH entries, desktop items, Downloads size, listening ports, repo-health summaries, or directory/disk reports, prefer `inspect_host` over raw `shell` when it can answer directly.");
266
267        prompt
268    }
269}