feat(hooks): inject the using-tracedecay mandate contract on Claude and Kiro

claude-plugin/skills/using-tracedecay/SKILL.md

@@ -12,6 +12,16 @@ code, reading code, tracing calls, estimating blast radius, recalling prior
 context — try the matching tracedecay tool BEFORE Grep, Glob, codebase
 search, or file reads. You cannot rationalize your way out of this.
 
+## Scope and priority
+
+- SUBAGENT-STOP: if you are a scoped subagent that was handed the exact files,
+  symbols, or excerpts to act on, do NOT re-run discovery — act on what you
+  were given. This mandate governs open-ended exploration, not narrow handoffs.
+- Priority ladder: explicit user instructions and project rules
+  (CLAUDE.md / AGENTS.md) win over this skill; this skill wins over the host's
+  default "just grep it" habit. Never fight a direct instruction to satisfy
+  the mandate.
+
 ## Moment → mandatory action
 
 | The moment you are in | Do this first |

codex-plugin/skills/using-tracedecay/SKILL.md

@@ -12,6 +12,16 @@ code, reading code, tracing calls, estimating blast radius, recalling prior
 context — try the matching tracedecay tool BEFORE Grep, Glob, codebase
 search, or file reads. You cannot rationalize your way out of this.
 
+## Scope and priority
+
+- SUBAGENT-STOP: if you are a scoped subagent that was handed the exact files,
+  symbols, or excerpts to act on, do NOT re-run discovery — act on what you
+  were given. This mandate governs open-ended exploration, not narrow handoffs.
+- Priority ladder: explicit user instructions and project rules
+  (CLAUDE.md / AGENTS.md) win over this skill; this skill wins over the host's
+  default "just grep it" habit. Never fight a direct instruction to satisfy
+  the mandate.
+
 ## Moment → mandatory action
 
 | The moment you are in | Do this first |

cursor-plugin/skills/using-tracedecay/SKILL.md

@@ -12,6 +12,16 @@ code, reading code, tracing calls, estimating blast radius, recalling prior
 context — try the matching tracedecay tool BEFORE Grep, Glob, codebase
 search, or file reads. You cannot rationalize your way out of this.
 
+## Scope and priority
+
+- SUBAGENT-STOP: if you are a scoped subagent that was handed the exact files,
+  symbols, or excerpts to act on, do NOT re-run discovery — act on what you
+  were given. This mandate governs open-ended exploration, not narrow handoffs.
+- Priority ladder: explicit user instructions and project rules
+  (CLAUDE.md / AGENTS.md) win over this skill; this skill wins over the host's
+  default "just grep it" habit. Never fight a direct instruction to satisfy
+  the mandate.
+
 ## Moment → mandatory action
 
 | The moment you are in | Do this first |

src/agents/kiro.rs

@@ -30,7 +30,7 @@ use super::{
 /// Kiro agent.
 pub struct KiroIntegration;
 
-const PROMPT_MARKER: &str = "## Prefer tracedecay MCP tools";
+const PROMPT_MARKER: &str = "## TraceDecay: mandatory tool routing";
 const PROMPT_END_MARKER: &str = "<!-- tracedecay:kiro:end -->";
 const KIRO_AGENT_NAME: &str = "tracedecay";
 const OWNED_AGENT_DESCRIPTION: &str =
@@ -615,28 +615,36 @@ fn prompt_rules_text() -> String {
 
 fn prompt_rules_text_without_end_marker() -> String {
     format!(
-        "## Prefer tracedecay MCP tools\n\n\
-Before reading source files or scanning the codebase, use the tracedecay MCP tools \
-(`tracedecay_context`, `tracedecay_search`, `tracedecay_callers`, `tracedecay_callees`, \
-`tracedecay_impact`, `tracedecay_node`, `tracedecay_files`, `tracedecay_affected`). \
-They provide semantic results from a pre-built local knowledge graph and are faster \
-than broad file reads.\n\n\
+        "## TraceDecay: mandatory tool routing\n\n\
+This project has a live TraceDecay code graph. If there is even a 1% chance a \
+tracedecay tool applies, you MUST use it BEFORE Kiro's file reads, codebase scan, \
+or `delegate`. This is a mandate, not a preference — you cannot rationalize your \
+way out of it.\n\n\
+| The moment you are in | Do this first |\n\
+|---|---|\n\
+| Searching for a symbol or concept | `tracedecay_search` (names) or `tracedecay_context` (concepts) |\n\
+| About to read a source file | `tracedecay_outline` -> `tracedecay_body` -> `tracedecay_read` slices |\n\
+| \"Who calls X\" / \"what does X call\" / \"trace this\" | `tracedecay_callers` / `tracedecay_callees` |\n\
+| About to change code, wondering what breaks | `tracedecay_impact` / `tracedecay_diff_context` / `tracedecay_affected` |\n\
+| Project / storage identity question | `tracedecay_active_project` / `tracedecay_storage_status` |\n\
+| A prior decision or past conversation is referenced | `tracedecay_message_search` / `tracedecay_lcm_expand_query` |\n\n\
+| Red-flag thought | Reality |\n\
+|---|---|\n\
+| \"Grep is faster for this\" | `tracedecay_search` is one call and pre-ranked. |\n\
+| \"I'll just read the whole file\" | `tracedecay_outline` / `tracedecay_body` answer at a fraction of the tokens. |\n\
+| \"This is a simple lookup\" | Simple lookups are exactly what the graph is for. |\n\
+| \"I already know this codebase\" | The graph is fresher than your memory. Check it. |\n\n\
+SUBAGENT-STOP: if you were handed the exact files, symbols, or excerpts to act on, \
+do NOT re-run discovery — act on what you were given. Explicit user instructions and \
+project rules (CLAUDE.md / AGENTS.md) win over this mandate; the mandate wins over the \
+default \"just grep it\" habit. Never fight a direct instruction to satisfy it.\n\n\
 Do not use Kiro's `delegate` tool for codebase exploration, architecture mapping, \
 call graph work, symbol lookup, or other code research until tracedecay MCP tools \
 have been tried. Delegation is still appropriate for long-running execution work \
 such as builds, tests, generated reports, or independent implementation tasks.\n\n\
-For project/storage identity questions, use `tracedecay_active_project` or \
-`tracedecay_storage_status` instead of inferring from marker files or \
-direct DB paths.\n\n\
-If a code analysis question cannot be fully answered by tracedecay MCP tools, prefer \
-built-in MCP tools first. If the user explicitly needs raw store inspection, use the \
-resolved graph DB path reported by `tracedecay_storage_status` rather than a hardcoded \
-repo path. Use SQL for structural queries that go beyond the MCP tools.\n\n\
 For durable project/user facts, prefer `tracedecay_fact_store`, \
-`tracedecay_fact_feedback`, and `tracedecay_memory_status` over ad-hoc notes. Use \
-`tracedecay_message_search` for active-project transcript recall when prior \
-conversation context matters. Do not store secrets, credentials, or unnecessary PII \
-in persistent facts.\n\n\
+`tracedecay_fact_feedback`, and `tracedecay_memory_status` over ad-hoc notes. Do not \
+store secrets, credentials, or unnecessary PII in persistent facts.\n\n\
 {cli_fallback}\n\n\
 If you discover a gap where an extractor, schema, or tracedecay tool could answer a \
 question natively, propose opening an issue at \

src/hooks/claude.rs

@@ -11,8 +11,8 @@ use super::codex::{
 };
 use super::post_tool_use::{notify_post_tool_use, CLAUDE_POST_TOOL_USE_SPEC};
 use super::steering::{
-    append_context_recovery_hint, cursor_index_signals_for_root, index_status_line,
-    session_start_from_compaction,
+    append_context_recovery_hint, append_tracedecay_bootstrap_context,
+    cursor_index_signals_for_root, index_status_line, session_start_from_compaction,
 };
 use super::tool_hints::{decide_hint, HintAgent, ToolHintInput};
 use super::{
@@ -122,13 +122,20 @@ pub async fn hook_claude_session_start() -> i32 {
     0
 }
 
-/// Builds the lean Claude `SessionStart` context for code workspaces.
-async fn claude_session_context_for_event(event_json: &str) -> String {
+/// Builds the Claude `SessionStart` context for code workspaces.
+///
+/// On an initialized project this injects the full `using-tracedecay`
+/// adoption contract (the `<EXTREMELY_IMPORTANT>` bootstrap) after the index
+/// status line, matching the Cursor and Codex session hooks so Claude's
+/// `SessionStart` channel carries the same mandate.
+pub async fn claude_session_context_for_event(event_json: &str) -> String {
     let parsed = serde_json::from_str::<Value>(event_json).unwrap_or(Value::Null);
     match codex_project_root_from_parsed_event(&parsed) {
         Some(root) => {
             let (staleness, _) = cursor_index_signals_for_root(&root).await;
-            index_status_line(true, staleness.as_deref())
+            let mut context = index_status_line(true, staleness.as_deref());
+            append_tracedecay_bootstrap_context(&mut context);
+            context
         }
         None if event_cwd_from_parsed(&parsed)
             .as_deref()

src/hooks/mod.rs

@@ -33,8 +33,8 @@ mod steering;
 pub mod tool_hints;
 
 pub use claude::{
-    evaluate_hook_decision, hook_claude_post_tool_use, hook_claude_session_start,
-    hook_pre_tool_use, hook_prompt_submit, hook_stop,
+    claude_session_context_for_event, evaluate_hook_decision, hook_claude_post_tool_use,
+    hook_claude_session_start, hook_pre_tool_use, hook_prompt_submit, hook_stop,
 };
 pub use codex::{
     codex_additional_context_json, codex_apply_patch_rel_paths, codex_project_root_from_event,

src/hooks/steering.rs

@@ -39,7 +39,7 @@ pub const CURSOR_PLUGIN_SKILLS: &[&str] = &[
 const TRACEDECAY_BOOTSTRAP_SKILL: &str =
     include_str!("../../cursor-plugin/skills/using-tracedecay/SKILL.md");
 
-fn append_tracedecay_bootstrap_context(s: &mut String) {
+pub(super) fn append_tracedecay_bootstrap_context(s: &mut String) {
     s.push_str(
         "<EXTREMELY_IMPORTANT>\n\
          This project has TraceDecay code-graph support. Below is the full `tracedecay:using-tracedecay` \

tests/agent_suite/kiro_agent_test.rs

@@ -131,7 +131,7 @@ fn test_install_creates_global_mcp_steering_agent_and_default() {
         "global Kiro tracedecay.md should exist"
     );
     let steering = std::fs::read_to_string(&steering_path).unwrap();
-    assert!(steering.contains("## Prefer tracedecay MCP tools"));
+    assert!(steering.contains("## TraceDecay: mandatory tool routing"));
     assert!(steering.contains("delegate"));
 
     let agent_path = home.join(".kiro/agents/tracedecay.json");
@@ -333,18 +333,18 @@ fn test_install_and_uninstall_preserve_existing_steering_content() {
     let user_steering = std::fs::read_to_string(&user_steering_path).unwrap();
     assert!(user_steering.contains("## Existing Kiro guidance"));
     assert!(user_steering.contains("Keep this user-authored guidance."));
-    assert!(!user_steering.contains("## Prefer tracedecay MCP tools"));
+    assert!(!user_steering.contains("## TraceDecay: mandatory tool routing"));
 
     let tracedecay_steering_path = home.join(".kiro/steering/tracedecay.md");
     let installed = std::fs::read_to_string(&tracedecay_steering_path).unwrap();
-    assert!(installed.contains("## Prefer tracedecay MCP tools"));
+    assert!(installed.contains("## TraceDecay: mandatory tool routing"));
 
     KiroIntegration.uninstall(&ctx).unwrap();
 
     let uninstalled = std::fs::read_to_string(&user_steering_path).unwrap();
     assert!(uninstalled.contains("## Existing Kiro guidance"));
     assert!(uninstalled.contains("Keep this user-authored guidance."));
-    assert!(!uninstalled.contains("## Prefer tracedecay MCP tools"));
+    assert!(!uninstalled.contains("## TraceDecay: mandatory tool routing"));
     assert!(!tracedecay_steering_path.exists());
 }
 
@@ -368,7 +368,7 @@ fn test_uninstall_preserves_user_steering_after_tracedecay_block() {
 
     let uninstalled = std::fs::read_to_string(&steering_path).unwrap();
     assert!(uninstalled.contains("User guidance appended after setup without a new heading."));
-    assert!(!uninstalled.contains("## Prefer tracedecay MCP tools"));
+    assert!(!uninstalled.contains("## TraceDecay: mandatory tool routing"));
 }
 
 #[test]
@@ -401,7 +401,7 @@ fn test_uninstall_removes_tracedecay_and_preserves_other_mcp_servers() {
     );
     let steering =
         std::fs::read_to_string(home.join(".kiro/steering/tracedecay.md")).unwrap_or_default();
-    assert!(!steering.contains("## Prefer tracedecay MCP tools"));
+    assert!(!steering.contains("## TraceDecay: mandatory tool routing"));
 }
 
 #[test]
@@ -525,7 +525,7 @@ fn test_healthcheck_fails_when_steering_lacks_owned_end_marker() {
     let steering_path = home.join(".kiro/steering/tracedecay.md");
     std::fs::write(
         &steering_path,
-        "## Prefer tracedecay MCP tools\n\nEdited tracedecay guidance without ownership marker.\n",
+        "## TraceDecay: mandatory tool routing\n\nEdited tracedecay guidance without ownership marker.\n",
     )
     .unwrap();
 

tests/agent_suite/prompt_rules_parity_test.rs

@@ -11,6 +11,7 @@ use crate::common::{EnvVarGuard, PROCESS_ENV_LOCK};
 
 const STANDARD_MARKER: &str = "## Prefer tracedecay MCP tools";
 const CLAUDE_MARKER: &str = "## MANDATORY: No Explore Agents When Tracedecay Is Available";
+const KIRO_MARKER: &str = "## TraceDecay: mandatory tool routing";
 const KIRO_END_MARKER: &str = "<!-- tracedecay:kiro:end -->";
 
 struct HostCase {
@@ -61,7 +62,7 @@ fn hosts() -> Vec<HostCase> {
         HostCase {
             id: "kiro",
             rules_path: |home| home.join(".kiro/steering/tracedecay.md"),
-            marker: STANDARD_MARKER,
+            marker: KIRO_MARKER,
             stale_block_tail: "\n\n<!-- tracedecay:kiro:end -->",
         },
     ]

tests/hooks_lsp_suite/hooks_test.rs

@@ -2,8 +2,8 @@ use crate::common::{EnvVarGuard, GLOBAL_DB_ENV, GLOBAL_DB_ENV_LOCK};
 use std::path::Path;
 use tracedecay::config::USER_DATA_DIR_ENV;
 use tracedecay::hooks::{
-    build_cursor_session_context, codex_additional_context_json, codex_apply_patch_rel_paths,
-    codex_project_root_from_event, codex_subagent_start_log_line,
+    build_cursor_session_context, claude_session_context_for_event, codex_additional_context_json,
+    codex_apply_patch_rel_paths, codex_project_root_from_event, codex_subagent_start_log_line,
     codex_user_prompt_submit_context_for_event, codex_workspace_status_from_event,
     cursor_branch_switch_target, cursor_project_root_from_event, cursor_session_start_json,
     cursor_shell_command_targets_project, cursor_shell_sync_plan,
@@ -828,6 +828,60 @@ fn test_build_codex_session_context_carries_full_steering() {
     assert!(uninit.contains("tracedecay_message_search"));
 }
 
+#[tokio::test]
+async fn test_claude_session_context_injects_bootstrap_when_initialized() {
+    // On an initialized project Claude's SessionStart additionalContext must
+    // carry the full using-tracedecay adoption contract, not just the index
+    // status line (matching Cursor and Codex).
+    let dir = tempfile::tempdir().unwrap();
+    std::fs::create_dir_all(dir.path().join(".tracedecay")).unwrap();
+    std::fs::write(dir.path().join(".tracedecay/tracedecay.db"), "").unwrap();
+    let event = serde_json::json!({
+        "hook_event_name": "SessionStart",
+        "cwd": dir.path().to_str().unwrap(),
+    })
+    .to_string();
+
+    let context = claude_session_context_for_event(&event).await;
+    assert!(
+        context.contains("tracedecay index status: "),
+        "initialized Claude context keeps the index status line: {context}"
+    );
+    assert!(
+        context.contains("<EXTREMELY_IMPORTANT>"),
+        "initialized Claude context must inject the bootstrap contract: {context}"
+    );
+    assert!(context.contains("tracedecay:using-tracedecay"));
+    assert!(context.contains("Grep is faster for this"));
+    assert!(
+        context.contains("SUBAGENT-STOP"),
+        "bootstrap must carry the scoped-subagent guard: {context}"
+    );
+    // The additionalContext channel wraps it as SessionStart context.
+    let json = codex_additional_context_json("SessionStart", &context);
+    assert!(json.contains("<EXTREMELY_IMPORTANT>"));
+}
+
+#[tokio::test]
+async fn test_claude_session_context_omits_bootstrap_for_unindexed_project() {
+    // A project-like workspace without an index gets the init nudge, not the
+    // full contract.
+    let dir = tempfile::tempdir().unwrap();
+    std::fs::write(dir.path().join("Cargo.toml"), "[package]\n").unwrap();
+    let event = serde_json::json!({
+        "hook_event_name": "SessionStart",
+        "cwd": dir.path().to_str().unwrap(),
+    })
+    .to_string();
+
+    let context = claude_session_context_for_event(&event).await;
+    assert!(context.contains("tracedecay init"));
+    assert!(
+        !context.contains("<EXTREMELY_IMPORTANT>"),
+        "unindexed workspaces should not inject the full contract: {context}"
+    );
+}
+
 #[test]
 fn test_build_codex_session_context_for_unindexed_project_suggests_init() {
     let context = tracedecay::hooks::build_codex_session_context_for_workspace(