diff --git a/ROADMAP.md b/ROADMAP.md
index f7111c6d..dbb89406 100644
--- a/ROADMAP.md
+++ b/ROADMAP.md
@@ -7731,3 +7731,5 @@ Original filing (2026-04-18): the session emitted `SessionStart hook (completed)
 781. **`api_http_error` was a single bucket for all HTTP errors; 401 auth and 429 rate-limit returned `hint:null` with no distinction** — dogfooded 2026-05-27 on `d9844cfe`. `classify_error_kind` had a single `api_http_error` arm for all API failures. 401 Unauthorized and 429 rate-limit errors emitted `error_kind:"api_http_error"` + `hint:null`, making it impossible for automation to distinguish auth misconfiguration from transient rate-limiting. Fixes: (1) added `api_auth_error` sub-classifier arm for 401/Unauthorized/authentication_error messages; (2) added `api_rate_limit_error` arm for 429/rate_limit messages; (3) added `fallback_hint_for_error_kind()` that derives a stable hint from the error kind when `split_error_hint` returns `None` (API layer never emits `\n`-delimited hints); (4) main JSON error emission path now calls `fallback_hint_for_error_kind` as fallback. Auth errors now return `api_auth_error` + env-var hint; rate-limit returns `api_rate_limit_error` + retry hint. Unit tests updated. 40 CLI contract tests pass. [SCOPE: claw-code] Source: Jobdori API error opacity probe on `d9844cfe`, 2026-05-27.
 
 782. **`claw acp start` returned `error_kind:"unsupported_acp_invocation"` + `hint:null` — remediation text was on same line** — dogfooded 2026-05-27 on `16c1117a` (pinpoint by Gaebal-gajae). The error message `"unsupported ACP invocation. Use `claw acp`, `claw acp serve`, `claw --acp`, or `claw -acp`."` had no `\n` delimiter, so `split_error_hint` returned `hint:null`. Automation could tell ACP was unsupported but could not read the remediation structurally. Fix: inserted a `\n` before the remediation text: `"unsupported ACP invocation. Use ... claw -acp.\nACP/Zed editor integration is currently a discoverability alias only; ..."`. Integration test `acp_unsupported_invocation_has_hint_782` added. 41 CLI contract tests pass. [SCOPE: claw-code] Source: Gaebal-gajae pinpoint + Jobdori implementation on `16c1117a`, 2026-05-27.
+
+783. **`claw --output-format json init` success envelope was missing `hint` field; idempotent re-init was not structurally detectable** — dogfooded 2026-05-27 on `32c9276f`. The init JSON envelope had no `hint` field (absent, not null), and no field to distinguish a fresh init from a re-init without checking `created.len() == 0`. Orchestrators had to inspect `created` array length to detect idempotent behavior. Fix: (1) added `hint` field to init JSON envelope — fresh path points at `CLAUDE.md + doctor`; idempotent path says "already initialised, run doctor"; (2) added `already_initialized: bool` field — `true` when `created` and `updated` are both empty (all artifacts skipped). Both test cases (fresh + re-init) covered by `init_json_envelope_has_hint_and_already_initialized_783`. 42 CLI contract tests pass. [SCOPE: claw-code] Source: Jobdori init-envelope probe on `32c9276f`, 2026-05-27.
diff --git a/rust/crates/rusty-claude-cli/src/main.rs b/rust/crates/rusty-claude-cli/src/main.rs
index 268d7f44..118f42c6 100644
--- a/rust/crates/rusty-claude-cli/src/main.rs
+++ b/rust/crates/rusty-claude-cli/src/main.rs
@@ -8179,15 +8179,26 @@ fn init_json_value(report: &crate::init::InitReport, message: &str) -> serde_jso
     // Derive top-level status: "ok" when all artifacts succeeded (created or
     // skipped = idempotent); no failure path exists today so always "ok".
     let status = "ok";
+    // #783: already_initialized lets orchestrators detect the idempotent case
+    // without checking created.len() == 0; hint gives a stable next-action pointer.
+    let already_initialized = report.artifacts_with_status(InitStatus::Created).is_empty()
+        && report.artifacts_with_status(InitStatus::Updated).is_empty();
+    let hint = if already_initialized {
+        "Workspace already initialised. Run `claw doctor` to verify health, or edit CLAUDE.md to customise guidance."
+    } else {
+        "Review and tailor CLAUDE.md to your project, then run `claw doctor` to verify the workspace."
+    };
     json!({
         "kind": "init",
         "action": "init",
         "status": status,
+        "already_initialized": already_initialized,
         "project_path": report.project_root.display().to_string(),
         "created": report.artifacts_with_status(InitStatus::Created),
         "updated": report.artifacts_with_status(InitStatus::Updated),
         "skipped": report.artifacts_with_status(InitStatus::Skipped),
         "artifacts": report.artifact_json_entries(),
+        "hint": hint,
         "next_step": crate::init::InitReport::NEXT_STEP,
         "message": message,
     })
diff --git a/rust/crates/rusty-claude-cli/tests/output_format_contract.rs b/rust/crates/rusty-claude-cli/tests/output_format_contract.rs
index 739cb503..85a6b0bc 100644
--- a/rust/crates/rusty-claude-cli/tests/output_format_contract.rs
+++ b/rust/crates/rusty-claude-cli/tests/output_format_contract.rs
@@ -2364,3 +2364,75 @@ fn acp_unsupported_invocation_has_hint_782() {
         "hint should explain the discoverability-only status, got: {hint:?}"
     );
 }
+
+#[test]
+fn init_json_envelope_has_hint_and_already_initialized_783() {
+    // #783: claw --output-format json init was missing the hint field entirely.
+    // Also added already_initialized: bool so orchestrators can detect the idempotent
+    // case without checking created.len() == 0.
+    let root = unique_temp_dir("init-hint-783");
+    fs::create_dir_all(&root).expect("temp dir");
+    std::process::Command::new("git")
+        .args(["init", "-q"])
+        .current_dir(&root)
+        .output()
+        .ok();
+
+    // Fresh init — already_initialized should be false, hint should mention CLAUDE.md
+    let output = run_claw(&root, &["--output-format", "json", "init"], &[]);
+    assert!(output.status.success(), "init should succeed");
+    let stdout = String::from_utf8_lossy(&output.stdout);
+    let stderr = String::from_utf8_lossy(&output.stderr);
+    let raw = if stdout.trim_start().starts_with('{') {
+        &*stdout
+    } else {
+        &*stderr
+    };
+    let parsed: serde_json::Value = serde_json::from_str(raw.trim()).unwrap_or_else(|_| {
+        // multi-line JSON; find the whole block
+        serde_json::from_str(raw).expect("should emit valid JSON")
+    });
+
+    assert_eq!(parsed["status"], "ok", "init should succeed");
+    assert!(
+        parsed.get("already_initialized").is_some(),
+        "init JSON must include already_initialized field (#783)"
+    );
+    assert_eq!(
+        parsed["already_initialized"], false,
+        "first init: already_initialized must be false"
+    );
+    let hint = parsed["hint"]
+        .as_str()
+        .expect("hint must be present and non-null (#783)");
+    assert!(!hint.is_empty(), "hint must not be empty");
+    assert!(
+        hint.contains("CLAUDE.md") || hint.contains("doctor"),
+        "fresh-init hint should mention CLAUDE.md or doctor, got: {hint:?}"
+    );
+
+    // Idempotent re-init — already_initialized should be true
+    let output2 = run_claw(&root, &["--output-format", "json", "init"], &[]);
+    assert!(output2.status.success(), "re-init should succeed");
+    let stdout2 = String::from_utf8_lossy(&output2.stdout);
+    let stderr2 = String::from_utf8_lossy(&output2.stderr);
+    let raw2 = if stdout2.trim_start().starts_with('{') {
+        &*stdout2
+    } else {
+        &*stderr2
+    };
+    let parsed2: serde_json::Value = serde_json::from_str(raw2.trim())
+        .or_else(|_| serde_json::from_str(raw2))
+        .expect("re-init should emit valid JSON");
+    assert_eq!(
+        parsed2["already_initialized"], true,
+        "re-init: already_initialized must be true"
+    );
+    let hint2 = parsed2["hint"]
+        .as_str()
+        .expect("hint must be present on re-init");
+    assert!(
+        hint2.contains("already") || hint2.contains("doctor"),
+        "re-init hint should acknowledge workspace exists, got: {hint2:?}"
+    );
+}