diff --git a/Cargo.lock b/Cargo.lock
index 3371c27..80552d9 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -72,7 +72,7 @@ dependencies = [
 
 [[package]]
 name = "anwesen"
-version = "0.2.0"
+version = "0.4.0"
 dependencies = [
  "anyhow",
  "axum",
diff --git a/Cargo.toml b/Cargo.toml
index a20fc1d..077aa42 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "anwesen"
 description = "Read-only HTTP daemon over a markdown vault, querying YAML frontmatter."
-version = "0.2.0"
+version = "0.4.0"
 edition = "2024"
 rust-version = "1.95"
 license = "BSD-3-Clause"
diff --git a/README.md b/README.md
index d4e2fc0..f51daa3 100644
--- a/README.md
+++ b/README.md
@@ -22,7 +22,7 @@ Anwesen answers three kinds of question over HTTP:
 
 The frontmatter index is built once at startup and kept current by watching the vault directory. The index lives in memory; a restart rebuilds it, and there is nothing on disk to corrupt or migrate.
 
-The same query-and-merge engine also runs offline, with no server: `anwesen merge` walks a directory, evaluates a query, and writes the merged markdown to stdout (see [Local generation](#local-generation)).
+The same query-and-merge engine also runs offline, with no server. `anwesen merge` walks a directory, evaluates a query, and writes the merged markdown to stdout; `anwesen query` writes the same JSON document `GET /query` returns (see [Local generation](#local-generation)).
 
 ## Quick start
 
@@ -52,14 +52,20 @@ Build one file out of many notes, without starting the daemon:
 anwesen merge --vault /path/to/vault --query 'tags=adr&__anw-order=title' > ADRs.md
 ```
 
+Ask which notes match, and what their frontmatter holds, without starting the daemon:
+
+```
+anwesen query --vault /path/to/vault --query 'tags=adr' | jq -r '.results[].path'
+```
+
 ## CLI
 
 ```
 anwesen serve  --vault <path> [--bind <addr:port>] [--log-level <level>]
-               [--uptrace-dsn <dsn> | --otlp-endpoint <url>]
-               [--otlp-header <key=value>]... [--otlp-slow-request-ms <n>]
+               [--otlp-slow-request-ms <n>]
 anwesen doctor --vault <path>
 anwesen merge  --vault <path> --query <query-string>
+anwesen query  --vault <path> --query <query-string>
 anwesen version
 ```
 
@@ -68,25 +74,64 @@ anwesen version
 | `--vault <path>`            | `ANWESEN_VAULT`                | _required_             | Path to the vault root.                                                       |
 | `--bind <addr:port>`        | `ANWESEN_BIND`                 | `127.0.0.1:8080`       | Listen address for `serve`.                                                   |
 | `--log-level <level>`       | `ANWESEN_LOG_LEVEL`            | `info`                 | `error`, `warn`, `info`, `debug`, or `trace`.                                  |
-| `--query <query-string>`    | --                             | _required for `merge`_ | A `/query` query string: frontmatter predicates plus `__anw-` controls.       |
-| `--uptrace-dsn <dsn>`       | `ANWESEN_UPTRACE_DSN`          | unset                  | uptrace DSN (`https://<token>@api.uptrace.dev`). Excludes `--otlp-endpoint`.  |
-| `--otlp-endpoint <url>`     | `ANWESEN_OTLP_ENDPOINT`        | unset                  | OTLP/HTTP base URL. Excludes `--uptrace-dsn`.                                 |
-| `--otlp-header <key=value>` | `ANWESEN_OTLP_HEADERS`         | none                   | Extra export header, repeatable. The env var takes a comma-separated list.    |
+| `--query <query-string>`    | `ANWESEN_QUERY`                | empty (match all)      | A `/query` query string: frontmatter predicates plus `__anw-` controls. `merge` and `query` only. |
 | `--otlp-slow-request-ms`    | `ANWESEN_OTLP_SLOW_REQUEST_MS` | `500`                  | Requests at or over this duration, or answering 5xx, also export a span.      |
 
-Every flag has a matching `ANWESEN_<UPPER>` environment variable, except
-`--otlp-header`, whose env var is the plural `ANWESEN_OTLP_HEADERS` because it
-takes a list. CLI flags win over env vars.
+Every flag has a matching `ANWESEN_<UPPER>` environment variable. CLI flags win
+over env vars.
 
-Telemetry is off unless `--uptrace-dsn` or `--otlp-endpoint` is set. With
-neither, nothing is exported and no exporter is built. The four telemetry
-flags apply to `serve` only.
+`--bind` and `--otlp-slow-request-ms` apply to `serve` only. Where telemetry is
+exported is configured entirely through the standard `OTEL_` variables below.
 
 - **`serve`** -- run the daemon: walk the vault, build the index, watch for changes, serve the API.
 - **`doctor`** -- walk the vault once and report what would stop clean ingestion: unreadable files, unparseable YAML, path collisions on the HTTP surface, and frontmatter type drift (the same key carrying incompatible types across notes). Read-only; non-zero exit if any issue is found.
 - **`merge`** -- one-shot local generation: walk the vault, evaluate `--query`, and write the merged markdown document to stdout. No server, no HTTP. See [Local generation](#local-generation).
+- **`query`** -- the same one-shot walk, writing the JSON document `GET /query` returns: which notes match, and what their frontmatter, `last_modified`, `etag` and `size` hold. No server, no HTTP. See [Local generation](#local-generation).
 - **`version`** -- print version and exit.
 
+## Telemetry
+
+anwesen exports OTLP metrics for every request, and a span for requests at or
+over `--otlp-slow-request-ms` or answering a 5xx. Export is configured through
+the standard OpenTelemetry environment variables, which the SDK reads directly:
+
+| Variable                               | Meaning                                                          |
+| -------------------------------------- | ---------------------------------------------------------------- |
+| `OTEL_EXPORTER_OTLP_ENDPOINT`          | Base URL. The SDK appends `/v1/metrics` and `/v1/traces`.        |
+| `OTEL_EXPORTER_OTLP_METRICS_ENDPOINT`  | Full metrics URL, used as given. Overrides the base for metrics. |
+| `OTEL_EXPORTER_OTLP_TRACES_ENDPOINT`   | Full traces URL, used as given. Overrides the base for traces.   |
+| `OTEL_EXPORTER_OTLP_HEADERS`           | Export headers, `key=value` comma-separated.                     |
+| `OTEL_EXPORTER_OTLP_PROTOCOL`          | `http/protobuf`, the default and the only value this build speaks. |
+| `OTEL_SERVICE_NAME`, `OTEL_RESOURCE_ATTRIBUTES` | Override the `anwesen` service identity.                |
+
+The per-signal `OTEL_EXPORTER_OTLP_METRICS_PROTOCOL` and
+`OTEL_EXPORTER_OTLP_TRACES_PROTOCOL` are read the same way.
+
+With none of the three endpoint variables set, telemetry is off: no exporter is
+built and the request middleware is not installed.
+
+Two settings fail at startup rather than export nowhere in silence:
+
+- A query or a fragment on `OTEL_EXPORTER_OTLP_ENDPOINT`. The base URL must be
+  a base URL; the SDK appends the signal path after whatever it is given.
+- A protocol other than `http/protobuf`. The binary ships the OTLP/HTTP
+  transport alone, so `grpc` would keep exporting over HTTP with nothing in the
+  log. Point the endpoint at the collector's HTTP port, not its gRPC one.
+
+uptrace:
+
+```
+OTEL_EXPORTER_OTLP_ENDPOINT=https://api.uptrace.dev
+OTEL_EXPORTER_OTLP_HEADERS=uptrace-dsn=https://TOKEN@api.uptrace.dev?grpc=4317
+```
+
+Paste the DSN from Project Settings into the header verbatim, tail and all --
+it is a credential there, not an address. The endpoint is the host alone.
+
+Removed in 0.3.0: `--uptrace-dsn`, `--otlp-endpoint`, `--otlp-header` and their
+`ANWESEN_` variables. Passing any of them fails at startup with the `OTEL_`
+replacement to use.
+
 ## HTTP API
 
 All endpoints are `GET` and return JSON unless noted.
@@ -136,7 +181,7 @@ ISO-8601 dates and RFC 3339 datetimes are coerced to typed dates at read time, s
 | `__anw-order=<key>[:asc\|:desc]` | path order | Order fragments (merge mode only).                                                             |
 | `__anw-kind=<key>`               | off        | Refuse a mixed merge unless every matched note shares one value for the key (merge mode only). |
 
-By default `/query` returns metadata only; fetch bodies with `/notes/<path>`.
+By default `/query` returns metadata only; fetch bodies with `/notes/<path>`. The same JSON document is available offline, without the daemon, via `anwesen query` (see [Local generation](#local-generation)).
 
 #### Markdown-merge mode
 
@@ -164,7 +209,11 @@ Returns vault path, note count, last index/event timestamps, watcher state, an i
 
 ## Local generation
 
-`anwesen merge` produces the markdown-merge document on the command line, with no server and no HTTP round-trip. It walks the vault, evaluates the query, and writes the merged document to stdout:
+Two subcommands answer a query on the command line, with no server and no HTTP round-trip: `merge` writes the merged markdown document, `query` writes the JSON projection. Both take the same `--vault` and `--query` flags, both walk the vault once, and both run the engine the endpoint runs -- so the output matches what the daemon would have returned for the same vault and query.
+
+### `merge`
+
+`anwesen merge` walks the vault, evaluates the query, and writes the merged document to stdout:
 
 ```
 anwesen merge --vault /path/to/vault --query 'tags=adr&__anw-order=title&__anw-kind=kind'
@@ -174,6 +223,24 @@ The `--query` string is the exact `/query` grammar: frontmatter predicates plus
 
 This is the materialization path: build a `CLAUDE.md`, a skill bundle, or any single file assembled from many notes, driven from a script or a one-off shell.
 
+### `query`
+
+`anwesen query` answers the other half: which notes match, and what their frontmatter holds. It writes the same JSON document `GET /query` returns -- `results`, `total`, `truncated`, with `path`, `frontmatter`, `last_modified`, `etag` and `size` per row -- on one line, ready for `jq`:
+
+```
+anwesen query --vault /path/to/vault --query 'kind=PDR&__anw-limit=1'
+```
+
+```json
+{"results":[{"path":"Projects/PDR-001-intro.md","frontmatter":{"kind":"PDR","num":1,"title":"PDR-001 Intro"},"last_modified":"2026-05-14T17:05:08Z","etag":"\"f657eab5...\"","size":57}],"total":2,"truncated":true}
+```
+
+`total` counts the full match set; `truncated` says the cap cut it.
+
+Bodies are elided here as they are on the endpoint; `merge` is the way to get them offline. `__anw-order` and `__anw-kind` are merge-mode controls and do not affect this output. A malformed query or an unreadable vault exits non-zero with the reason on stderr; an empty match set is an empty `results` list and exit `0`.
+
+A script can therefore move between the daemon and the CLI without a second parser: same shape, same field names, same timestamp dialect.
+
 ## Design notes
 
 - **In place, read-only.** Anwesen reads the same directory Obsidian writes to and never writes back. The vault stays editable in Obsidian with no coordination, and there is no write API by design.
diff --git a/src/app.rs b/src/app.rs
index f3ee5fc..cc4bcf6 100644
--- a/src/app.rs
+++ b/src/app.rs
@@ -121,6 +121,12 @@ pub struct Anwesen {
     /// Request-level telemetry handle ([ANW-37]). `None` disables export and
     /// the request middleware entirely.
     pub telemetry: Option<Arc<Telemetry>>,
+    /// Set once the supervisor tree is up. Hydra's `Application::run` logs a
+    /// start failure and returns normally, so `serve` cannot tell a clean
+    /// shutdown from a tree that never came up. `main` reads this after `run`
+    /// and exits nonzero when it is still false, which is what lets systemd
+    /// retry ([ANW-45](https://crvrs.youtrack.cloud/issue/ANW-45)).
+    pub started: Arc<AtomicBool>,
 }
 
 impl Anwesen {
@@ -133,6 +139,7 @@ impl Anwesen {
             store: NoteStore::new(),
             health: HealthState::new(),
             telemetry,
+            started: Arc::new(AtomicBool::new(false)),
         }
     }
 }
@@ -187,10 +194,12 @@ impl Application for Anwesen {
             .child_spec(),
         ];
 
-        Supervisor::with_children(children)
+        let pid = Supervisor::with_children(children)
             .strategy(SupervisionStrategy::OneForOne)
             .start_link(SupervisorOptions::new().name("anwesen_root"))
-            .await
+            .await?;
+        self.started.store(true, Ordering::Release);
+        Ok(pid)
     }
 }
 
diff --git a/src/cli.rs b/src/cli.rs
index 155ab5b..32bbced 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -4,18 +4,27 @@
 //!
 //! ```text
 //! anwesen serve  --vault <path> [--bind <addr:port>] [--log-level <level>]
-//!                [--uptrace-dsn <dsn> | --otlp-endpoint <url>]
-//!                [--otlp-header <key=value>]... [--otlp-slow-request-ms <n>]
+//!                [--otlp-slow-request-ms <n>]
 //! anwesen doctor --vault <path> [--log-level <level>]
 //! anwesen merge  --vault <path> [--query <string>] [--log-level <level>]
+//! anwesen query  --vault <path> [--query <string>] [--log-level <level>]
 //! anwesen version
 //! ```
 //!
-//! `--bind` and the OTLP telemetry flags are `serve`-only ([ANW-37]);
+//! `merge` and `query` differ only in what they write -- the merged markdown
+//! document or the `/query` JSON projection ([ANW-43]) -- so they share one
+//! [`VaultQueryArgs`] flag set and cannot drift.
+//!
+//! `--bind` and `--otlp-slow-request-ms` are `serve`-only ([ANW-37]);
 //! `doctor` and `merge` do not bind a port; `version` takes no flags. Each
 //! flag has a matching `ANWESEN_<UPPER>` environment variable and CLI wins
-//! over env per the manual. With no `--otlp-endpoint`/`--uptrace-dsn`,
-//! telemetry is off and the server behaves exactly as without these flags.
+//! over env per the manual.
+//!
+//! Telemetry export is configured through the standard `OTEL_EXPORTER_OTLP_*`
+//! environment variables ([ANW-42](https://crvrs.youtrack.cloud/issue/ANW-42)).
+//! With none of them set, telemetry is off and the server behaves as it did
+//! before telemetry existed. The removed flags below are still parsed so an
+//! upgrade fails loudly instead of dropping export config in silence.
 
 use std::net::SocketAddr;
 use std::path::PathBuf;
@@ -37,7 +46,11 @@ pub enum Command {
     Doctor(DoctorArgs),
     /// Walk the vault once, evaluate the query, and write the merged markdown
     /// document to stdout. One-shot; no server. Read-only.
-    Merge(MergeArgs),
+    Merge(VaultQueryArgs),
+    /// Walk the vault once, evaluate the query, and write the same JSON
+    /// document `GET /query` returns to stdout. One-shot; no server.
+    /// Read-only.
+    Query(VaultQueryArgs),
     /// Print the version and exit.
     Version,
 }
@@ -56,25 +69,22 @@ pub struct ServeArgs {
     #[arg(long, env = "ANWESEN_LOG_LEVEL", default_value = "info")]
     pub log_level: LogLevel,
 
-    /// uptrace DSN shorthand (`https://<token>@api.uptrace.dev`), parsed
-    /// into the OTLP endpoint plus an `uptrace-dsn` header. Mutually
-    /// exclusive with --otlp-endpoint. When this and --otlp-endpoint are
-    /// both unset, telemetry is fully off (ANW-37).
-    #[arg(long, env = "ANWESEN_UPTRACE_DSN")]
+    /// Removed (ANW-42): use `OTEL_EXPORTER_OTLP_ENDPOINT` plus
+    /// `OTEL_EXPORTER_OTLP_HEADERS=uptrace-dsn=<dsn>`. Still accepted so
+    /// startup fails with that message rather than exporting nowhere.
+    #[arg(long, env = "ANWESEN_UPTRACE_DSN", hide = true)]
     pub uptrace_dsn: Option<String>,
 
-    /// Generic OTLP/HTTP endpoint base URL for telemetry export. The
-    /// per-signal path (`/v1/metrics`, `/v1/traces`) is appended by the
-    /// exporter. Mutually exclusive with --uptrace-dsn.
-    #[arg(long, env = "ANWESEN_OTLP_ENDPOINT")]
+    /// Removed (ANW-42): use `OTEL_EXPORTER_OTLP_ENDPOINT`.
+    #[arg(long, env = "ANWESEN_OTLP_ENDPOINT", hide = true)]
     pub otlp_endpoint: Option<String>,
 
-    /// Extra OTLP export header as `key=value`, repeatable. On the env var
-    /// (`ANWESEN_OTLP_HEADERS`) pass a comma-separated `key=value` list.
+    /// Removed (ANW-42): use `OTEL_EXPORTER_OTLP_HEADERS`.
     #[arg(
         long = "otlp-header",
         env = "ANWESEN_OTLP_HEADERS",
-        value_delimiter = ','
+        value_delimiter = ',',
+        hide = true
     )]
     pub otlp_headers: Vec<String>,
 
@@ -96,8 +106,9 @@ pub struct DoctorArgs {
     pub log_level: LogLevel,
 }
 
+/// Flags shared by the two one-shot subcommands, `merge` and `query`.
 #[derive(Debug, clap::Args)]
-pub struct MergeArgs {
+pub struct VaultQueryArgs {
     /// Path to the vault root.
     #[arg(long, env = "ANWESEN_VAULT")]
     pub vault: PathBuf,
@@ -105,12 +116,12 @@ pub struct MergeArgs {
     /// Query in the `/query` query-string grammar, for example
     /// `tags=anwesen&__anw-kind=skill&__anw-order=order`. The `__anw-kind`
     /// homogeneity guard and `__anw-order` fragment ordering ride inside this
-    /// string -- there are no separate flags. Empty merges every note under
-    /// the vault root.
+    /// string -- there are no separate flags. `__anw-kind` and `__anw-order`
+    /// apply to `merge` only. Empty matches every note under the vault root.
     #[arg(long, env = "ANWESEN_QUERY", default_value = "")]
     pub query: String,
 
-    /// Log verbosity. Logs go to stderr; the merged document goes to stdout.
+    /// Log verbosity. Logs go to stderr; the document goes to stdout.
     #[arg(long, env = "ANWESEN_LOG_LEVEL", default_value = "info")]
     pub log_level: LogLevel,
 }
@@ -172,6 +183,34 @@ mod tests {
         }
     }
 
+    /// The removed telemetry flags still parse, hidden from `--help`. Clap
+    /// rejecting them as unknown would say nothing about the `OTEL_`
+    /// replacement; the migration error in `telemetry::TelemetryConfig`
+    /// needs the values to reach it (ANW-42).
+    #[test]
+    fn serve_still_parses_the_removed_telemetry_flags() {
+        let cli = parse(&[
+            "serve",
+            "--vault",
+            "/tmp/v",
+            "--uptrace-dsn",
+            "https://tok@api.uptrace.dev",
+            "--otlp-endpoint",
+            "https://collector.example.com",
+            "--otlp-header",
+            "authorization=Bearer xyz",
+        ])
+        .expect("parse");
+        match cli.command {
+            Command::Serve(a) => {
+                assert!(a.uptrace_dsn.is_some());
+                assert!(a.otlp_endpoint.is_some());
+                assert_eq!(a.otlp_headers, vec!["authorization=Bearer xyz".to_string()]);
+            }
+            _ => panic!("expected serve"),
+        }
+    }
+
     #[test]
     fn serve_rejects_malformed_bind_at_parse_time() {
         let err = parse(&["serve", "--vault", "/tmp/v", "--bind", "not-an-addr"]).unwrap_err();
@@ -242,6 +281,47 @@ mod tests {
         assert_eq!(err.kind(), clap::error::ErrorKind::UnknownArgument);
     }
 
+    #[test]
+    fn query_takes_the_same_flags_as_merge() {
+        let cli = parse(&[
+            "query",
+            "--vault",
+            "/tmp/v",
+            "--query",
+            "tags=anwesen&__anw-limit=5",
+            "--log-level",
+            "warn",
+        ])
+        .expect("parse");
+        match cli.command {
+            Command::Query(a) => {
+                assert_eq!(a.vault, PathBuf::from("/tmp/v"));
+                assert_eq!(a.query, "tags=anwesen&__anw-limit=5");
+                assert!(matches!(a.log_level, LogLevel::Warn));
+            }
+            _ => panic!("expected query"),
+        }
+    }
+
+    #[test]
+    fn query_requires_vault_and_defaults_the_query() {
+        assert!(parse(&["query"]).is_err());
+        match parse(&["query", "--vault", "/tmp/v"])
+            .expect("parse")
+            .command
+        {
+            Command::Query(a) => assert_eq!(a.query, ""),
+            _ => panic!("expected query"),
+        }
+    }
+
+    #[test]
+    fn query_rejects_bind() {
+        // --bind is serve-only; query does not listen.
+        let err = parse(&["query", "--vault", "/tmp/v", "--bind", "0.0.0.0:9000"]).unwrap_err();
+        assert_eq!(err.kind(), clap::error::ErrorKind::UnknownArgument);
+    }
+
     #[test]
     fn version_takes_no_flags() {
         assert!(matches!(
diff --git a/src/doctor.rs b/src/doctor.rs
index 58f3e8d..f53f09f 100644
--- a/src/doctor.rs
+++ b/src/doctor.rs
@@ -46,7 +46,7 @@ pub struct DriftShape {
     /// `"bool"`, `"number"`, `"string"`, `"date"`, `"list"`, `"mapping"`.
     pub shape: &'static str,
     pub count: usize,
-    /// Up to [`DRIFT_SAMPLES_PER_SHAPE`] vault-relative paths exhibiting
+    /// Up to `DRIFT_SAMPLES_PER_SHAPE` vault-relative paths exhibiting
     /// this shape, in the order they were scanned.
     pub samples: Vec<String>,
 }
diff --git a/src/http.rs b/src/http.rs
index 48ec78e..1d847a9 100644
--- a/src/http.rs
+++ b/src/http.rs
@@ -22,7 +22,7 @@ use axum::http::{HeaderMap, HeaderValue, StatusCode};
 use axum::middleware::{Next, from_fn, from_fn_with_state};
 use axum::response::{IntoResponse, Response};
 use axum::routing::get;
-use chrono::{DateTime, SecondsFormat, Utc};
+use chrono::{DateTime, Utc};
 use http_body::Body as _;
 use hydra::Process;
 use serde::Serialize;
@@ -32,17 +32,11 @@ use std::path::PathBuf;
 
 use crate::app::RestartCounters;
 use crate::health::HealthState;
+use crate::query::rfc3339_z;
 use crate::store::NoteStore;
 use crate::telemetry::{self, Telemetry, TraceHeaders};
 use crate::vault::{Note, frontmatter_to_json};
 
-/// Canonical RFC 3339 form with a `Z` suffix -- the shape the User Manual
-/// example uses for `last_modified`. Centralized here so every HTTP
-/// `last_modified` field stays in the same dialect.
-fn rfc3339_z(dt: DateTime<Utc>) -> String {
-    dt.to_rfc3339_opts(SecondsFormat::Secs, true)
-}
-
 /// Shared state injected into every handler.
 #[derive(Clone)]
 pub struct HttpState {
@@ -819,18 +813,23 @@ mod tests {
     }
 
     /// With telemetry installed, a normal request is answered byte-for-byte
-    /// as without it. The exporter points at an unreachable local port, so
-    /// export fails instantly in the background and never touches the
-    /// response path.
+    /// as without it. The test process sets no `OTEL_EXPORTER_OTLP_*`
+    /// variables, so the exporter aims at the SDK default and fails in the
+    /// background without ever touching the response path.
     #[tokio::test]
     async fn telemetry_layer_does_not_alter_responses() {
-        use crate::telemetry::{self, RawTelemetryArgs, TelemetryConfig};
+        use crate::telemetry::{self, OtelEnv, RawTelemetryArgs, TelemetryConfig};
 
-        let cfg = TelemetryConfig::resolve(RawTelemetryArgs {
-            otlp_endpoint: Some("http://127.0.0.1:9".into()),
-            slow_request_ms: 500,
-            ..Default::default()
-        })
+        let cfg = TelemetryConfig::resolve(
+            &RawTelemetryArgs {
+                slow_request_ms: 500,
+                ..Default::default()
+            },
+            OtelEnv {
+                endpoint: Some("http://127.0.0.1:9".into()),
+                ..OtelEnv::default()
+            },
+        )
         .unwrap()
         .expect("telemetry on");
         let tel = Arc::new(telemetry::init(cfg).expect("telemetry init"));
diff --git a/src/lib.rs b/src/lib.rs
index 59f1689..818b23e 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -10,7 +10,7 @@ pub mod app;
 pub mod doctor;
 pub mod health;
 pub mod http;
-pub mod merge;
+pub mod oneshot;
 pub mod query;
 pub mod store;
 pub mod telemetry;
diff --git a/src/main.rs b/src/main.rs
index f573e3f..05027d9 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,16 +1,17 @@
 //! Anwesen: read-only HTTP daemon over a markdown vault.
 //!
-//! This module wires the CLI to the `serve`, `doctor`, `merge`, and
+//! This module wires the CLI to the `serve`, `doctor`, `merge`, `query`, and
 //! `version` subcommands.
 
 mod cli;
 
 use std::sync::Arc;
+use std::sync::atomic::Ordering;
 
 use anwesen::app::Anwesen;
 use anwesen::doctor;
-use anwesen::merge;
-use anwesen::telemetry::{self, RawTelemetryArgs, TelemetryConfig};
+use anwesen::oneshot;
+use anwesen::telemetry::{self, OtelEnv, RawTelemetryArgs, TelemetryConfig};
 use anyhow::Result;
 use clap::Parser;
 use hydra::Application;
@@ -25,14 +26,18 @@ fn main() -> Result<()> {
     match cli.command {
         Command::Serve(args) => {
             init_logging(args.log_level);
-            // Resolve telemetry config before the supervisor starts; an
-            // unset endpoint leaves it `None` (export off, behaves as today).
-            let telemetry = match TelemetryConfig::resolve(RawTelemetryArgs {
-                uptrace_dsn: args.uptrace_dsn,
-                otlp_endpoint: args.otlp_endpoint,
-                otlp_headers: args.otlp_headers,
-                slow_request_ms: args.otlp_slow_request_ms,
-            })? {
+            // Resolve telemetry config before the supervisor starts; no
+            // OTEL_EXPORTER_OTLP_* endpoint leaves it `None` (export off,
+            // no middleware). A removed flag is a startup error (ANW-42).
+            let telemetry = match TelemetryConfig::resolve(
+                &RawTelemetryArgs {
+                    uptrace_dsn: args.uptrace_dsn,
+                    otlp_endpoint: args.otlp_endpoint,
+                    otlp_headers: args.otlp_headers,
+                    slow_request_ms: args.otlp_slow_request_ms,
+                },
+                OtelEnv::from_env(),
+            )? {
                 Some(cfg) => Some(Arc::new(telemetry::init(cfg)?)),
                 None => None,
             };
@@ -42,12 +47,22 @@ fn main() -> Result<()> {
                 telemetry = telemetry.is_some(),
                 "anwesen serve: starting supervisor tree"
             );
+            let app = Anwesen::new(args.vault, args.bind, telemetry.clone());
+            let started = app.started.clone();
             // Blocks until the supervisor exits (SIGTERM / SIGINT / crash).
-            Anwesen::new(args.vault, args.bind, telemetry.clone()).run();
+            app.run();
             // Flush and shut down exporters after the server loop returns.
             if let Some(telemetry) = telemetry {
                 telemetry.shutdown();
             }
+            // `run` returns normally whether the tree came up or never
+            // started, so a failed start would otherwise look like a clean
+            // exit and systemd's `Restart=on-failure` would not retry
+            // (ANW-45). Exit nonzero when the tree never came up.
+            if !started.load(Ordering::Acquire) {
+                tracing::error!("anwesen serve: supervisor tree failed to start");
+                std::process::exit(1);
+            }
         }
         Command::Doctor(args) => {
             init_logging(args.log_level);
@@ -59,13 +74,26 @@ fn main() -> Result<()> {
         }
         Command::Merge(args) => {
             init_logging(args.log_level);
-            match merge::run(&args.vault, &args.query) {
+            match oneshot::merge(&args.vault, &args.query) {
                 // `print!`, not `println!`: the merged document is byte-stable
                 // and byte-identical to the HTTP merge body, which carries no
                 // trailing newline. An empty match set prints nothing, exit 0.
                 Ok(doc) => print!("{doc}"),
                 Err(e) => {
-                    eprint!("{}", e.render());
+                    eprint!("{}", e.render("merge"));
+                    std::process::exit(1);
+                }
+            }
+        }
+        Command::Query(args) => {
+            init_logging(args.log_level);
+            match oneshot::query_json(&args.vault, &args.query) {
+                // `println!` here, unlike `merge`: the JSON body carries no
+                // trailing newline either, but stdout is one document per
+                // line for the shells and `jq` pipelines this exists for.
+                Ok(doc) => println!("{doc}"),
+                Err(e) => {
+                    eprint!("{}", e.render("query"));
                     std::process::exit(1);
                 }
             }
diff --git a/src/merge.rs b/src/merge.rs
deleted file mode 100644
index a9b6d2b..0000000
--- a/src/merge.rs
+++ /dev/null
@@ -1,205 +0,0 @@
-//! One-shot local markdown-merge for the `anwesen merge` subcommand ([ANW-27]).
-//!
-//! Walks a vault directory once (the same [`vault::scan`] as `doctor`),
-//! evaluates the `--query` string, and assembles the merged markdown document
-//! with [`query::execute_merge`] -- the very engine the HTTP `/query` merge
-//! mode ([ANW-26]) uses. CLI and HTTP output are therefore byte-identical for
-//! the same vault and query. No HTTP, no watcher, no persistent index.
-
-use std::fmt::Write as _;
-use std::path::Path;
-
-use crate::query::{self, MergeError, QueryError};
-use crate::store::NoteStore;
-use crate::vault::{self, ScanIssue};
-
-/// Why a one-shot merge could not produce a document.
-#[derive(Debug)]
-pub enum MergeCliError {
-    /// The `--query` string did not parse. Same grammar, same message as the
-    /// HTTP `/query` `400`.
-    Query(QueryError),
-    /// One or more files could not be read, or their frontmatter did not
-    /// parse. Same hard-failure posture as `doctor`; soft warnings (e.g. a
-    /// non-mapping frontmatter root) are ignored, matching what `serve`
-    /// ingests.
-    Scan(Vec<ScanIssue>),
-    /// The `__anw-kind` homogeneity guard rejected the matched set. The
-    /// `String` is the same naming message the HTTP path returns as `400`,
-    /// surfaced here on stderr instead.
-    Kind(String),
-}
-
-impl MergeCliError {
-    /// Render the error for stderr. One concern per line, deterministic so the
-    /// stderr surface is golden-testable.
-    #[must_use]
-    pub fn render(&self) -> String {
-        match self {
-            Self::Query(e) => format!("{e}\n"),
-            Self::Scan(issues) => {
-                let mut s = String::from("merge: cannot read vault\n");
-                for issue in issues {
-                    let _ = writeln!(s, "  {}: {}", issue.path.display(), issue.kind);
-                }
-                s
-            }
-            Self::Kind(msg) => msg.clone(),
-        }
-    }
-}
-
-/// Walk `vault_root`, evaluate `raw_query`, and return the merged document.
-///
-/// On success the returned `String` is byte-identical to the HTTP merge body
-/// for the same vault and query. An empty match set yields an empty string.
-///
-/// # Errors
-/// - [`MergeCliError::Query`] when `raw_query` is malformed;
-/// - [`MergeCliError::Scan`] when the directory is unreadable or any file's
-///   frontmatter fails to parse;
-/// - [`MergeCliError::Kind`] when the `__anw-kind` homogeneity guard fails.
-pub fn run(vault_root: &Path, raw_query: &str) -> Result<String, MergeCliError> {
-    let parsed = query::parse(raw_query).map_err(MergeCliError::Query)?;
-
-    let scan = vault::scan(vault_root);
-    if !scan.issues.is_empty() {
-        return Err(MergeCliError::Scan(scan.issues));
-    }
-
-    // The merge engine reads from a NoteStore exactly as the HTTP path does;
-    // a one-shot `replace` is the whole "index" this subcommand needs.
-    let store = NoteStore::new();
-    store.replace(scan.notes);
-
-    query::execute_merge(&store, &parsed)
-        .map_err(|MergeError::KindGuard(msg)| MergeCliError::Kind(msg))
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use std::fs;
-    use std::path::Path;
-    use tempfile::TempDir;
-
-    fn write(root: &Path, rel: &str, body: &str) {
-        let p = root.join(rel);
-        if let Some(parent) = p.parent() {
-            fs::create_dir_all(parent).unwrap();
-        }
-        fs::write(p, body).unwrap();
-    }
-
-    #[test]
-    fn merges_bodies_with_source_markers() {
-        let tmp = TempDir::new().unwrap();
-        write(tmp.path(), "a.md", "---\nnum: 1\n---\nalpha\n");
-        write(tmp.path(), "b.md", "---\nnum: 2\n---\nbeta\n");
-        let out = run(tmp.path(), "").unwrap();
-        // Body is frontmatter-stripped; fragments join with a blank line and
-        // there is no trailing newline -- byte-identical to the HTTP body.
-        assert_eq!(
-            out,
-            "<!-- source: a.md -->\nalpha\n\n\n<!-- source: b.md -->\nbeta\n"
-        );
-    }
-
-    #[test]
-    fn order_desc_then_path_tiebreak() {
-        let tmp = TempDir::new().unwrap();
-        write(tmp.path(), "a.md", "---\nnum: 1\n---\nlow\n");
-        write(tmp.path(), "b.md", "---\nnum: 3\n---\nhigh\n");
-        write(tmp.path(), "c.md", "---\nnum: 2\n---\nmid\n");
-        let out = run(tmp.path(), "__anw-order=num:desc").unwrap();
-        let bodies: Vec<&str> = out
-            .lines()
-            .filter(|l| !l.starts_with("<!--") && !l.is_empty())
-            .collect();
-        assert_eq!(bodies, vec!["high", "mid", "low"]);
-    }
-
-    #[test]
-    fn empty_match_set_is_empty_string() {
-        let tmp = TempDir::new().unwrap();
-        write(tmp.path(), "a.md", "---\ntags: [x]\n---\nbody\n");
-        // Predicate matches nothing.
-        assert_eq!(run(tmp.path(), "tags=nope").unwrap(), "");
-    }
-
-    #[test]
-    fn empty_vault_is_empty_string() {
-        let tmp = TempDir::new().unwrap();
-        assert_eq!(run(tmp.path(), "").unwrap(), "");
-    }
-
-    #[test]
-    fn kind_guard_passes_when_uniform() {
-        let tmp = TempDir::new().unwrap();
-        write(tmp.path(), "a.md", "---\nkind: skill\n---\nA\n");
-        write(tmp.path(), "b.md", "---\nkind: skill\n---\nB\n");
-        assert!(run(tmp.path(), "__anw-kind=kind").is_ok());
-    }
-
-    #[test]
-    fn kind_guard_rejects_distinct_values_naming_offenders() {
-        let tmp = TempDir::new().unwrap();
-        write(tmp.path(), "a.md", "---\nkind: skill\n---\nA\n");
-        write(tmp.path(), "b.md", "---\nkind: note\n---\nB\n");
-        let err = run(tmp.path(), "__anw-kind=kind").unwrap_err();
-        let msg = err.render();
-        assert!(msg.contains("distinct values found"));
-        assert!(msg.contains("a.md"));
-        assert!(msg.contains("b.md"));
-    }
-
-    #[test]
-    fn kind_guard_rejects_missing_key() {
-        let tmp = TempDir::new().unwrap();
-        write(tmp.path(), "a.md", "---\nkind: skill\n---\nA\n");
-        write(tmp.path(), "b.md", "---\n---\nB\n");
-        let err = run(tmp.path(), "__anw-kind=kind").unwrap_err();
-        assert!(matches!(err, MergeCliError::Kind(_)));
-        assert!(err.render().contains("notes missing the key"));
-    }
-
-    #[test]
-    fn malformed_query_is_reported() {
-        let tmp = TempDir::new().unwrap();
-        write(tmp.path(), "a.md", "---\n---\nbody\n");
-        let err = run(tmp.path(), "x__bogus=1").unwrap_err();
-        assert!(matches!(err, MergeCliError::Query(_)));
-        // Non-empty stderr surface.
-        assert!(!err.render().is_empty());
-    }
-
-    #[test]
-    fn unparseable_frontmatter_is_a_scan_error() {
-        let tmp = TempDir::new().unwrap();
-        write(tmp.path(), "bad.md", "---\n:: :: ::\n---\n");
-        let err = run(tmp.path(), "").unwrap_err();
-        assert!(matches!(err, MergeCliError::Scan(_)));
-        assert!(err.render().contains("cannot read vault"));
-        assert!(err.render().contains("bad.md"));
-    }
-
-    #[test]
-    fn output_matches_http_engine_for_same_vault_and_query() {
-        // The shared-engine check: the CLI path and a directly-built store
-        // feeding execute_merge must produce the identical document.
-        let tmp = TempDir::new().unwrap();
-        write(tmp.path(), "a.md", "---\nnum: 2\n---\nA body\n");
-        write(tmp.path(), "b.md", "---\nnum: 1\n---\nB body\n");
-        let raw = "__anw-order=num:asc";
-
-        let cli = run(tmp.path(), raw).unwrap();
-
-        let scan = vault::scan(tmp.path());
-        let store = NoteStore::new();
-        store.replace(scan.notes);
-        let parsed = query::parse(raw).unwrap();
-        let direct = query::execute_merge(&store, &parsed).unwrap();
-
-        assert_eq!(cli, direct);
-    }
-}
diff --git a/src/oneshot.rs b/src/oneshot.rs
new file mode 100644
index 0000000..54697ee
--- /dev/null
+++ b/src/oneshot.rs
@@ -0,0 +1,354 @@
+//! One-shot local query evaluation for the `anwesen merge` ([ANW-27]) and
+//! `anwesen query` ([ANW-43]) subcommands.
+//!
+//! Both walk a vault directory once (the same [`vault::scan`] as `doctor`),
+//! evaluate the `--query` string, and hand the resulting store to the very
+//! engine the HTTP `/query` endpoint uses: [`query::execute_merge`] for the
+//! merged markdown document ([ANW-26]), [`query::execute`] for the JSON
+//! projection. CLI and HTTP output are therefore byte-identical for the same
+//! vault and query. No HTTP, no watcher, no persistent index.
+
+use std::fmt::Write as _;
+use std::path::Path;
+use std::sync::Arc;
+
+use crate::query::{self, MergeError, ParsedQuery, QueryError};
+use crate::store::NoteStore;
+use crate::vault::{self, ScanIssue};
+
+/// Why a one-shot evaluation could not produce a document.
+#[derive(Debug)]
+pub enum OneshotError {
+    /// The `--query` string did not parse. Same grammar, same message as the
+    /// HTTP `/query` `400`.
+    Query(QueryError),
+    /// One or more files could not be read, or their frontmatter did not
+    /// parse. Same hard-failure posture as `doctor`; soft warnings (e.g. a
+    /// non-mapping frontmatter root) are ignored, matching what `serve`
+    /// ingests.
+    Scan(Vec<ScanIssue>),
+    /// The `__anw-kind` homogeneity guard rejected the matched set. The
+    /// `String` is the same naming message the HTTP path returns as `400`,
+    /// surfaced here on stderr instead. Merge mode only -- the JSON
+    /// projection does not run the guard, exactly as the endpoint does not.
+    Kind(String),
+}
+
+impl OneshotError {
+    /// Render the error for stderr. One concern per line, deterministic so the
+    /// stderr surface is golden-testable. `subcommand` names the caller so the
+    /// scan header reads `merge:` or `query:` as the operator invoked it.
+    #[must_use]
+    pub fn render(&self, subcommand: &str) -> String {
+        match self {
+            Self::Query(e) => format!("{e}\n"),
+            Self::Scan(issues) => {
+                let mut s = format!("{subcommand}: cannot read vault\n");
+                for issue in issues {
+                    let _ = writeln!(s, "  {}: {}", issue.path.display(), issue.kind);
+                }
+                s
+            }
+            Self::Kind(msg) => msg.clone(),
+        }
+    }
+}
+
+/// Parse `raw_query` and load `vault_root` into a one-shot store.
+///
+/// The single path both subcommands take, so the two cannot drift in how they
+/// parse a query or how strictly they read a vault.
+fn load(vault_root: &Path, raw_query: &str) -> Result<(ParsedQuery, Arc<NoteStore>), OneshotError> {
+    let parsed = query::parse(raw_query).map_err(OneshotError::Query)?;
+
+    let scan = vault::scan(vault_root);
+    if !scan.issues.is_empty() {
+        return Err(OneshotError::Scan(scan.issues));
+    }
+
+    // The engine reads from a NoteStore exactly as the HTTP path does; a
+    // one-shot `replace` is the whole "index" these subcommands need.
+    let store = NoteStore::new();
+    store.replace(scan.notes);
+    Ok((parsed, store))
+}
+
+/// Walk `vault_root`, evaluate `raw_query`, and return the merged document.
+///
+/// On success the returned `String` is byte-identical to the HTTP merge body
+/// for the same vault and query. An empty match set yields an empty string.
+///
+/// # Errors
+/// - [`OneshotError::Query`] when `raw_query` is malformed;
+/// - [`OneshotError::Scan`] when the directory is unreadable or any file's
+///   frontmatter fails to parse;
+/// - [`OneshotError::Kind`] when the `__anw-kind` homogeneity guard fails.
+pub fn merge(vault_root: &Path, raw_query: &str) -> Result<String, OneshotError> {
+    let (parsed, store) = load(vault_root, raw_query)?;
+    query::execute_merge(&store, &parsed)
+        .map_err(|MergeError::KindGuard(msg)| OneshotError::Kind(msg))
+}
+
+/// Walk `vault_root`, evaluate `raw_query`, and return the JSON document
+/// `GET /query` returns for the same vault and query -- same projection, same
+/// `results` / `total` / `truncated` shape, same compact serialization, so a
+/// script moving between daemon and CLI needs no second parser ([ANW-43]).
+///
+/// Result ordering and the `__anw-limit` semantics are the endpoint's,
+/// because this is the endpoint's [`query::execute`]: paths ascending, the
+/// cap applied after `total` is counted.
+///
+/// # Errors
+/// - [`OneshotError::Query`] when `raw_query` is malformed;
+/// - [`OneshotError::Scan`] when the directory is unreadable or any file's
+///   frontmatter fails to parse.
+///
+/// # Panics
+/// If the response fails to serialize -- unreachable, as the HTTP handler's
+/// identical `to_vec` call also treats it: every field is a string, a number,
+/// or frontmatter already converted to `serde_json::Value`.
+pub fn query_json(vault_root: &Path, raw_query: &str) -> Result<String, OneshotError> {
+    let (parsed, store) = load(vault_root, raw_query)?;
+    let response = query::execute(&store, &parsed, query::rfc3339_z);
+    Ok(serde_json::to_string(&response).expect("query response serializes"))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::fs;
+    use std::path::Path;
+    use tempfile::TempDir;
+
+    fn write(root: &Path, rel: &str, body: &str) {
+        let p = root.join(rel);
+        if let Some(parent) = p.parent() {
+            fs::create_dir_all(parent).unwrap();
+        }
+        fs::write(p, body).unwrap();
+    }
+
+    #[test]
+    fn merges_bodies_with_source_markers() {
+        let tmp = TempDir::new().unwrap();
+        write(tmp.path(), "a.md", "---\nnum: 1\n---\nalpha\n");
+        write(tmp.path(), "b.md", "---\nnum: 2\n---\nbeta\n");
+        let out = merge(tmp.path(), "").unwrap();
+        // Body is frontmatter-stripped; fragments join with a blank line and
+        // there is no trailing newline -- byte-identical to the HTTP body.
+        assert_eq!(
+            out,
+            "<!-- source: a.md -->\nalpha\n\n\n<!-- source: b.md -->\nbeta\n"
+        );
+    }
+
+    #[test]
+    fn order_desc_then_path_tiebreak() {
+        let tmp = TempDir::new().unwrap();
+        write(tmp.path(), "a.md", "---\nnum: 1\n---\nlow\n");
+        write(tmp.path(), "b.md", "---\nnum: 3\n---\nhigh\n");
+        write(tmp.path(), "c.md", "---\nnum: 2\n---\nmid\n");
+        let out = merge(tmp.path(), "__anw-order=num:desc").unwrap();
+        let bodies: Vec<&str> = out
+            .lines()
+            .filter(|l| !l.starts_with("<!--") && !l.is_empty())
+            .collect();
+        assert_eq!(bodies, vec!["high", "mid", "low"]);
+    }
+
+    #[test]
+    fn empty_match_set_is_empty_string() {
+        let tmp = TempDir::new().unwrap();
+        write(tmp.path(), "a.md", "---\ntags: [x]\n---\nbody\n");
+        // Predicate matches nothing.
+        assert_eq!(merge(tmp.path(), "tags=nope").unwrap(), "");
+    }
+
+    #[test]
+    fn empty_vault_is_empty_string() {
+        let tmp = TempDir::new().unwrap();
+        assert_eq!(merge(tmp.path(), "").unwrap(), "");
+    }
+
+    #[test]
+    fn kind_guard_passes_when_uniform() {
+        let tmp = TempDir::new().unwrap();
+        write(tmp.path(), "a.md", "---\nkind: skill\n---\nA\n");
+        write(tmp.path(), "b.md", "---\nkind: skill\n---\nB\n");
+        assert!(merge(tmp.path(), "__anw-kind=kind").is_ok());
+    }
+
+    #[test]
+    fn kind_guard_rejects_distinct_values_naming_offenders() {
+        let tmp = TempDir::new().unwrap();
+        write(tmp.path(), "a.md", "---\nkind: skill\n---\nA\n");
+        write(tmp.path(), "b.md", "---\nkind: note\n---\nB\n");
+        let err = merge(tmp.path(), "__anw-kind=kind").unwrap_err();
+        let msg = err.render("merge");
+        assert!(msg.contains("distinct values found"));
+        assert!(msg.contains("a.md"));
+        assert!(msg.contains("b.md"));
+    }
+
+    #[test]
+    fn kind_guard_rejects_missing_key() {
+        let tmp = TempDir::new().unwrap();
+        write(tmp.path(), "a.md", "---\nkind: skill\n---\nA\n");
+        write(tmp.path(), "b.md", "---\n---\nB\n");
+        let err = merge(tmp.path(), "__anw-kind=kind").unwrap_err();
+        assert!(matches!(err, OneshotError::Kind(_)));
+        assert!(err.render("merge").contains("notes missing the key"));
+    }
+
+    #[test]
+    fn malformed_query_is_reported() {
+        let tmp = TempDir::new().unwrap();
+        write(tmp.path(), "a.md", "---\n---\nbody\n");
+        let err = merge(tmp.path(), "x__bogus=1").unwrap_err();
+        assert!(matches!(err, OneshotError::Query(_)));
+        // Non-empty stderr surface.
+        assert!(!err.render("merge").is_empty());
+    }
+
+    #[test]
+    fn unparseable_frontmatter_is_a_scan_error() {
+        let tmp = TempDir::new().unwrap();
+        write(tmp.path(), "bad.md", "---\n:: :: ::\n---\n");
+        let err = merge(tmp.path(), "").unwrap_err();
+        assert!(matches!(err, OneshotError::Scan(_)));
+        assert!(err.render("merge").contains("cannot read vault"));
+        assert!(err.render("merge").contains("bad.md"));
+    }
+
+    #[test]
+    fn output_matches_http_engine_for_same_vault_and_query() {
+        // The shared-engine check: the CLI path and a directly-built store
+        // feeding execute_merge must produce the identical document.
+        let tmp = TempDir::new().unwrap();
+        write(tmp.path(), "a.md", "---\nnum: 2\n---\nA body\n");
+        write(tmp.path(), "b.md", "---\nnum: 1\n---\nB body\n");
+        let raw = "__anw-order=num:asc";
+
+        let cli = merge(tmp.path(), raw).unwrap();
+
+        let scan = vault::scan(tmp.path());
+        let store = NoteStore::new();
+        store.replace(scan.notes);
+        let parsed = query::parse(raw).unwrap();
+        let direct = query::execute_merge(&store, &parsed).unwrap();
+
+        assert_eq!(cli, direct);
+    }
+
+    // --- `query` (ANW-43) --------------------------------------------------
+
+    fn json(doc: &str) -> serde_json::Value {
+        serde_json::from_str(doc).expect("query output parses as JSON")
+    }
+
+    #[test]
+    fn query_projects_path_frontmatter_and_file_facts() {
+        let tmp = TempDir::new().unwrap();
+        write(
+            tmp.path(),
+            "Projects/alpha.md",
+            "---\ntags: [project]\nversion: 2\n---\nbody\n",
+        );
+        let doc = json(&query_json(tmp.path(), "").unwrap());
+
+        assert_eq!(doc["total"], 1);
+        assert_eq!(doc["truncated"], false);
+        let row = &doc["results"][0];
+        assert_eq!(row["path"], "Projects/alpha.md");
+        assert_eq!(row["frontmatter"]["version"], 2);
+        assert_eq!(row["frontmatter"]["tags"][0], "project");
+        assert_eq!(row["size"], 40);
+        // The endpoint's timestamp dialect, seconds precision with a Z suffix.
+        let lm = row["last_modified"].as_str().unwrap();
+        assert!(lm.ends_with('Z'), "{lm}");
+        assert!(row["etag"].as_str().unwrap().starts_with('"'));
+        // The body is elided here as it is on the endpoint.
+        assert!(row.get("body").is_none());
+    }
+
+    #[test]
+    fn query_predicates_filter_and_limit_truncates_after_total() {
+        let tmp = TempDir::new().unwrap();
+        write(tmp.path(), "a.md", "---\nstatus: draft\n---\nA\n");
+        write(tmp.path(), "b.md", "---\nstatus: draft\n---\nB\n");
+        write(tmp.path(), "c.md", "---\nstatus: done\n---\nC\n");
+
+        let filtered = json(&query_json(tmp.path(), "status=draft").unwrap());
+        assert_eq!(filtered["total"], 2);
+        assert_eq!(filtered["results"].as_array().unwrap().len(), 2);
+
+        let capped = json(&query_json(tmp.path(), "status=draft&__anw-limit=1").unwrap());
+        // `total` counts the full match set; the cap keeps the first row.
+        assert_eq!(capped["total"], 2);
+        assert_eq!(capped["truncated"], true);
+        assert_eq!(capped["results"].as_array().unwrap().len(), 1);
+        assert_eq!(capped["results"][0]["path"], "a.md");
+    }
+
+    #[test]
+    fn query_empty_match_set_is_an_empty_result_list() {
+        let tmp = TempDir::new().unwrap();
+        write(tmp.path(), "a.md", "---\ntags: [x]\n---\nbody\n");
+        let doc = json(&query_json(tmp.path(), "tags=nope").unwrap());
+        assert_eq!(doc["total"], 0);
+        assert_eq!(doc["truncated"], false);
+        assert!(doc["results"].as_array().unwrap().is_empty());
+    }
+
+    #[test]
+    fn query_malformed_query_is_reported_naming_the_subcommand() {
+        let tmp = TempDir::new().unwrap();
+        write(tmp.path(), "a.md", "---\n---\nbody\n");
+        let err = query_json(tmp.path(), "x__bogus=1").unwrap_err();
+        assert!(matches!(err, OneshotError::Query(_)));
+        assert!(!err.render("query").is_empty());
+    }
+
+    #[test]
+    fn query_unparseable_frontmatter_is_a_scan_error() {
+        let tmp = TempDir::new().unwrap();
+        write(tmp.path(), "bad.md", "---\n:: :: ::\n---\n");
+        let err = query_json(tmp.path(), "").unwrap_err();
+        assert!(err.render("query").starts_with("query: cannot read vault"));
+        assert!(err.render("query").contains("bad.md"));
+    }
+
+    #[test]
+    fn query_kind_guard_does_not_apply() {
+        // `__anw-kind` guards merge output only. Parsing it must not make the
+        // JSON path fail on a mixed set, matching the endpoint.
+        let tmp = TempDir::new().unwrap();
+        write(tmp.path(), "a.md", "---\nkind: skill\n---\nA\n");
+        write(tmp.path(), "b.md", "---\nkind: note\n---\nB\n");
+        assert!(merge(tmp.path(), "__anw-kind=kind").is_err());
+        let doc = json(&query_json(tmp.path(), "__anw-kind=kind").unwrap());
+        assert_eq!(doc["total"], 2);
+    }
+
+    #[test]
+    fn query_output_matches_the_http_projection_byte_for_byte() {
+        // The shared-engine check for the JSON surface: same store, same
+        // `execute`, same serialization as the `/query` handler.
+        let tmp = TempDir::new().unwrap();
+        write(tmp.path(), "a.md", "---\nnum: 2\n---\nA body\n");
+        write(tmp.path(), "b.md", "---\nnum: 1\n---\nB body\n");
+        let raw = "__anw-limit=1";
+
+        let cli = query_json(tmp.path(), raw).unwrap();
+
+        let scan = vault::scan(tmp.path());
+        let store = NoteStore::new();
+        store.replace(scan.notes);
+        let parsed = query::parse(raw).unwrap();
+        let direct =
+            serde_json::to_string(&query::execute(&store, &parsed, crate::query::rfc3339_z))
+                .unwrap();
+
+        assert_eq!(cli, direct);
+    }
+}
diff --git a/src/query.rs b/src/query.rs
index bf301f7..afd9fbf 100644
--- a/src/query.rs
+++ b/src/query.rs
@@ -11,14 +11,14 @@
 //! `__in` / `__all` are comma-separated; unknown operators are `400`.
 //!
 //! Predicates are evaluated by iterating the in-memory [`NoteStore`] and
-//! applying each [`Predicate::matches`] in turn. At the documented scale
+//! applying each [`Predicate`] in turn. At the documented scale
 //! (low-thousands-of-notes vaults) this is sub-millisecond; see
 //! [[ADR-009 Reverse ADR-002 In-Memory Evaluation No Tantivy]] for the
 //! call to keep evaluation in-memory rather than carrying a Tantivy index.
 
 use std::collections::BTreeMap;
 
-use chrono::{DateTime, NaiveDate};
+use chrono::{DateTime, NaiveDate, SecondsFormat, Utc};
 use regex::Regex;
 use serde::Serialize;
 use serde_json::Value as JsonValue;
@@ -280,6 +280,16 @@ fn hex_value(b: u8) -> Option<u8> {
     }
 }
 
+/// Canonical RFC 3339 form with a `Z` suffix -- the shape the User Manual
+/// example uses for `last_modified`. It lives next to [`ResultEntry`] because
+/// it is the projection's dialect: both the HTTP handlers and the offline
+/// `anwesen query` subcommand ([ANW-43]) format timestamps with it, so the
+/// two surfaces cannot drift.
+#[must_use]
+pub fn rfc3339_z(dt: DateTime<Utc>) -> String {
+    dt.to_rfc3339_opts(SecondsFormat::Secs, true)
+}
+
 /// One result row in the `/query` response. Per User Manual the body is
 /// elided -- consumers fetch bodies via `/notes/<path>` if needed.
 #[derive(Debug, Serialize)]
diff --git a/src/telemetry.rs b/src/telemetry.rs
index a685b2d..15511c6 100644
--- a/src/telemetry.rs
+++ b/src/telemetry.rs
@@ -12,140 +12,288 @@
 //!   the propagated context. Every other request stays metrics-only, so the
 //!   ~3.6k requests/min steady state does not drown the trace backend.
 //!
-//! When no OTLP endpoint (or uptrace DSN) is configured, [`init`] returns
+//! Transport configuration comes from the standard `OTEL_EXPORTER_OTLP_*`
+//! environment variables only, read by the `OpenTelemetry` SDK itself
+//! ([ANW-42](https://crvrs.youtrack.cloud/issue/ANW-42)). anwesen parses no
+//! addresses and appends no per-signal paths. It checks two things at
+//! startup, both cases the SDK would otherwise export nowhere in silence:
+//!
+//! - `OTEL_EXPORTER_OTLP_ENDPOINT` carries no query or fragment, because the
+//!   SDK's own concatenation mangles those (measured against a sink: a
+//!   `?tail` base sends `POST /?tail/v1/metrics`, a `#frag` base sends
+//!   `POST /`).
+//! - No protocol variable asks for anything but `http/protobuf`, the only
+//!   transport this binary is built with.
+//!
+//! When no endpoint variable is set, [`TelemetryConfig::resolve`] returns
 //! `None`, the request middleware is not installed, and the server behaves
 //! exactly as it did before this module existed. External installs run
 //! unchanged.
-//!
-//! Config mirrors the gestell uptrace surface (see the gestell PDR-GES-136
-//! `[otel]` section): a `uptrace_dsn` shorthand, or a generic endpoint plus
-//! headers.
 
-use std::collections::HashMap;
 use std::time::{Duration, SystemTime};
 
-use anyhow::{Context as _, anyhow, bail};
+use anyhow::{Context as _, bail};
 use axum::http::HeaderMap;
 use opentelemetry::KeyValue;
 use opentelemetry::metrics::{Counter, Histogram, MeterProvider as _};
 use opentelemetry::propagation::{Extractor, TextMapPropagator};
 use opentelemetry::trace::{Span, SpanKind, Tracer, TracerProvider as _};
-use opentelemetry_otlp::{
-    MetricExporter, Protocol, SpanExporter, WithExportConfig, WithHttpConfig,
-};
+use opentelemetry_otlp::{MetricExporter, SpanExporter};
 use opentelemetry_sdk::Resource;
 use opentelemetry_sdk::metrics::{PeriodicReader, SdkMeterProvider};
 use opentelemetry_sdk::propagation::TraceContextPropagator;
 use opentelemetry_sdk::trace::Sampler;
 use opentelemetry_sdk::trace::{SdkTracer, SdkTracerProvider};
-use opentelemetry_semantic_conventions::resource::SERVICE_VERSION;
+use opentelemetry_semantic_conventions::resource::{SERVICE_NAME, SERVICE_VERSION};
 
-/// Raw telemetry options as parsed by clap on the `serve` command. Resolved
-/// into an [`Option<TelemetryConfig>`] by [`TelemetryConfig::resolve`].
+/// The removed telemetry options, still parsed so their presence is an error
+/// rather than a silent config drop on upgrade
+/// ([ANW-42](https://crvrs.youtrack.cloud/issue/ANW-42)), plus the one
+/// surviving option. Resolved into an [`Option<TelemetryConfig>`] by
+/// [`TelemetryConfig::resolve`].
 #[derive(Debug, Default)]
 pub struct RawTelemetryArgs {
-    /// `--uptrace-dsn` / `ANWESEN_UPTRACE_DSN`.
+    /// Removed `--uptrace-dsn` / `ANWESEN_UPTRACE_DSN`.
     pub uptrace_dsn: Option<String>,
-    /// `--otlp-endpoint` / `ANWESEN_OTLP_ENDPOINT`.
+    /// Removed `--otlp-endpoint` / `ANWESEN_OTLP_ENDPOINT`.
     pub otlp_endpoint: Option<String>,
-    /// `--otlp-header` / `ANWESEN_OTLP_HEADERS`, each `key=value`.
+    /// Removed `--otlp-header` / `ANWESEN_OTLP_HEADERS`.
     pub otlp_headers: Vec<String>,
-    /// `--otlp-slow-request-ms` / `ANWESEN_OTLP_SLOW_REQUEST_MS`.
+    /// `--otlp-slow-request-ms` / `ANWESEN_OTLP_SLOW_REQUEST_MS`. Kept: it
+    /// decides when anwesen emits a span, not where the export goes, and no
+    /// standard variable covers it.
     pub slow_request_ms: u64,
 }
 
-/// A resolved, telemetry-on configuration. Built only when an endpoint or a
-/// DSN is present; absence is represented by `Ok(None)` from [`resolve`].
+/// The OTLP transport variables the SDK reads, captured once at startup so
+/// the telemetry-on decision and the startup checks stay pure functions of
+/// them. Values are the raw strings; anwesen does not parse them beyond the
+/// checks in [`check_generic_endpoint`] and [`check_protocols`].
+#[derive(Debug, Default, Clone, PartialEq, Eq)]
+pub struct OtelEnv {
+    /// `OTEL_EXPORTER_OTLP_ENDPOINT`: base URL, per-signal path appended by
+    /// the SDK.
+    pub endpoint: Option<String>,
+    /// `OTEL_EXPORTER_OTLP_METRICS_ENDPOINT`: full URL, used verbatim.
+    pub metrics_endpoint: Option<String>,
+    /// `OTEL_EXPORTER_OTLP_TRACES_ENDPOINT`: full URL, used verbatim.
+    pub traces_endpoint: Option<String>,
+    /// `OTEL_EXPORTER_OTLP_PROTOCOL`.
+    pub protocol: Option<String>,
+    /// `OTEL_EXPORTER_OTLP_METRICS_PROTOCOL`.
+    pub metrics_protocol: Option<String>,
+    /// `OTEL_EXPORTER_OTLP_TRACES_PROTOCOL`.
+    pub traces_protocol: Option<String>,
+}
+
+impl OtelEnv {
+    /// Read the transport variables from the process environment. An empty or
+    /// whitespace-only value counts as unset: an empty endpoint would
+    /// otherwise turn telemetry on and export to the SDK's `localhost:4318`
+    /// default.
+    #[must_use]
+    pub fn from_env() -> Self {
+        let var = |name: &str| {
+            std::env::var(name)
+                .ok()
+                .map(|v| v.trim().to_string())
+                .filter(|v| !v.is_empty())
+        };
+        Self {
+            endpoint: var("OTEL_EXPORTER_OTLP_ENDPOINT"),
+            metrics_endpoint: var("OTEL_EXPORTER_OTLP_METRICS_ENDPOINT"),
+            traces_endpoint: var("OTEL_EXPORTER_OTLP_TRACES_ENDPOINT"),
+            protocol: var("OTEL_EXPORTER_OTLP_PROTOCOL"),
+            metrics_protocol: var("OTEL_EXPORTER_OTLP_METRICS_PROTOCOL"),
+            traces_protocol: var("OTEL_EXPORTER_OTLP_TRACES_PROTOCOL"),
+        }
+    }
+
+    /// Whether any endpoint variable is set. No endpoint means telemetry off.
+    fn any_endpoint(&self) -> bool {
+        self.endpoint.is_some() || self.metrics_endpoint.is_some() || self.traces_endpoint.is_some()
+    }
+
+    /// The endpoint to name in the startup log: the generic base when set,
+    /// otherwise whichever per-signal URL is.
+    fn describe(&self) -> &str {
+        self.endpoint
+            .as_deref()
+            .or(self.metrics_endpoint.as_deref())
+            .or(self.traces_endpoint.as_deref())
+            .unwrap_or("")
+    }
+}
+
+/// A resolved, telemetry-on configuration. Built only when an endpoint
+/// variable is set; absence is represented by `Ok(None)` from [`resolve`].
+/// It carries no transport settings: the exporters read those from the
+/// environment themselves.
 ///
 /// [`resolve`]: TelemetryConfig::resolve
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct TelemetryConfig {
-    /// OTLP/HTTP base URL. The exporter appends the per-signal path
-    /// (`/v1/metrics`, `/v1/traces`).
-    pub endpoint: String,
-    /// Export headers (for uptrace, the `uptrace-dsn` entry) as ordered
-    /// `(name, value)` pairs.
-    pub headers: Vec<(String, String)>,
     /// A request at or over this duration, or answering a 5xx, is recorded
     /// as a server span.
     pub slow_request: Duration,
+    /// The transport variables, kept for the startup log line only.
+    env: OtelEnv,
 }
 
 impl TelemetryConfig {
-    /// Resolve raw clap options into an optional config.
+    /// Resolve the surviving option plus the OTLP transport variables into an
+    /// optional config.
     ///
-    /// - Both `uptrace_dsn` and `otlp_endpoint` set is an error (they are
-    ///   two ways to name the same endpoint).
-    /// - Neither set means telemetry is off: `Ok(None)`.
-    /// - A malformed `key=value` header or an unparseable DSN is an error,
-    ///   surfaced at startup rather than silently dropping export.
+    /// - A removed flag or `ANWESEN_` variable is an error naming its `OTEL_`
+    ///   replacement: a deployment exporting today must fail one restart
+    ///   rather than go quiet.
+    /// - No endpoint variable set means telemetry is off: `Ok(None)`.
+    /// - A query or fragment on `OTEL_EXPORTER_OTLP_ENDPOINT` is an error.
+    /// - A protocol this binary cannot speak is an error.
     ///
     /// # Errors
-    /// Returns an error when the two endpoint sources conflict, a header is
-    /// not `key=value`, or the uptrace DSN cannot be parsed.
-    pub fn resolve(raw: RawTelemetryArgs) -> anyhow::Result<Option<Self>> {
-        let slow_request = Duration::from_millis(raw.slow_request_ms);
-        let mut headers = parse_headers(&raw.otlp_headers)?;
-
-        match (raw.uptrace_dsn, raw.otlp_endpoint) {
-            (Some(_), Some(_)) => {
-                bail!("--uptrace-dsn and --otlp-endpoint are mutually exclusive");
-            }
-            (Some(dsn), None) => {
-                let (endpoint, dsn_header) = parse_uptrace_dsn(&dsn)?;
-                // The DSN header leads; any explicit --otlp-header follows.
-                headers.insert(0, dsn_header);
-                Ok(Some(Self {
-                    endpoint,
-                    headers,
-                    slow_request,
-                }))
-            }
-            (None, Some(endpoint)) => Ok(Some(Self {
-                endpoint,
-                headers,
-                slow_request,
-            })),
-            (None, None) => Ok(None),
+    /// Returns an error when a removed option is present, when the generic
+    /// endpoint carries a query or a fragment, or when a protocol variable
+    /// asks for anything but `http/protobuf`.
+    pub fn resolve(raw: &RawTelemetryArgs, env: OtelEnv) -> anyhow::Result<Option<Self>> {
+        check_removed(raw)?;
+        if !env.any_endpoint() {
+            return Ok(None);
         }
+        if let Some(endpoint) = &env.endpoint {
+            check_generic_endpoint(endpoint)?;
+        }
+        check_protocols(&env)?;
+        Ok(Some(Self {
+            slow_request: Duration::from_millis(raw.slow_request_ms),
+            env,
+        }))
     }
 }
 
-/// Parse `key=value` header specs. Whitespace around key and value is
-/// trimmed; an empty key or a spec with no `=` is an error.
-fn parse_headers(specs: &[String]) -> anyhow::Result<Vec<(String, String)>> {
-    let mut out = Vec::with_capacity(specs.len());
-    for spec in specs {
-        let (k, v) = spec
-            .split_once('=')
-            .ok_or_else(|| anyhow!("OTLP header {spec:?} is not key=value"))?;
-        let k = k.trim();
-        if k.is_empty() {
-            bail!("OTLP header {spec:?} has an empty key");
+/// Fail on any removed telemetry option, naming the `OTEL_` variable that
+/// replaces it. Silence is the expensive failure here: an upgrade that drops
+/// the export config would stop telemetry with nothing in the log.
+fn check_removed(raw: &RawTelemetryArgs) -> anyhow::Result<()> {
+    let removed: [(&str, &str, bool); 3] = [
+        (
+            "--uptrace-dsn / ANWESEN_UPTRACE_DSN",
+            "OTEL_EXPORTER_OTLP_ENDPOINT=https://api.uptrace.dev plus \
+             OTEL_EXPORTER_OTLP_HEADERS=uptrace-dsn=<the DSN, verbatim>",
+            raw.uptrace_dsn.is_some(),
+        ),
+        (
+            "--otlp-endpoint / ANWESEN_OTLP_ENDPOINT",
+            "OTEL_EXPORTER_OTLP_ENDPOINT",
+            raw.otlp_endpoint.is_some(),
+        ),
+        (
+            "--otlp-header / ANWESEN_OTLP_HEADERS",
+            "OTEL_EXPORTER_OTLP_HEADERS",
+            !raw.otlp_headers.is_empty(),
+        ),
+    ];
+    for (option, replacement, present) in removed {
+        if present {
+            bail!("{option} was removed in anwesen 0.3.0; use {replacement} instead");
         }
-        out.push((k.to_string(), v.trim().to_string()));
     }
-    Ok(out)
+    Ok(())
 }
 
-/// Parse an uptrace DSN (`https://<token>@host[:port]`) into the OTLP
-/// endpoint base URL and the `uptrace-dsn` header uptrace expects. The full
-/// DSN is echoed as the header value per uptrace's ingest contract.
-fn parse_uptrace_dsn(dsn: &str) -> anyhow::Result<(String, (String, String))> {
-    let dsn = dsn.trim();
-    let (scheme, rest) = dsn
-        .split_once("://")
-        .context("uptrace DSN has no scheme (expected https://<token>@host)")?;
-    // Host is whatever follows the credentials `@`; a DSN with no `@` is
-    // treated as endpoint-only (lenient, though real uptrace DSNs carry a
-    // token).
-    let host = rest.rsplit_once('@').map_or(rest, |(_, h)| h);
-    let host = host.trim_end_matches('/');
-    if host.is_empty() {
-        bail!("uptrace DSN has no host");
+/// Reject a query or fragment on `OTEL_EXPORTER_OTLP_ENDPOINT`. The SDK
+/// appends the per-signal path to this value textually, so a `?grpc=4317`
+/// tail sends `POST /?grpc=4317/v1/metrics` and a `#frag` tail sends
+/// `POST /` -- both dead exports, neither logged. Measured against a sink on
+/// opentelemetry-otlp 0.32 ([ANW-42]). A path prefix composes correctly and
+/// is left alone.
+///
+/// [ANW-42]: https://crvrs.youtrack.cloud/issue/ANW-42
+fn check_generic_endpoint(endpoint: &str) -> anyhow::Result<()> {
+    if let Some(bad) = endpoint.find(['?', '#']) {
+        let tail = &endpoint[bad..];
+        bail!(
+            "OTEL_EXPORTER_OTLP_ENDPOINT {endpoint:?} has a trailing {tail:?}; \
+             the exporter would append the signal path after it and export nowhere. \
+             Pass the base URL alone, and put an uptrace DSN in \
+             OTEL_EXPORTER_OTLP_HEADERS=uptrace-dsn=<the DSN, verbatim>"
+        );
     }
-    let endpoint = format!("{scheme}://{host}");
-    Ok((endpoint, ("uptrace-dsn".to_string(), dsn.to_string())))
+    Ok(())
+}
+
+/// The one OTLP protocol this binary speaks. `opentelemetry-otlp` is built
+/// with the `http-proto` feature alone (Cargo.toml), so neither `grpc` nor
+/// `http/json` has a transport behind it.
+const SUPPORTED_PROTOCOL: &str = "http/protobuf";
+
+/// Reject a protocol variable this binary cannot honor. The exporter builder
+/// picks its transport at compile time, so `OTEL_EXPORTER_OTLP_PROTOCOL=grpc`
+/// does not switch anything: the export keeps going out as HTTP protobuf,
+/// with nothing in the log (measured, [ANW-42]). An operator who follows
+/// uptrace's console to the gRPC port would get exactly the dead-silent
+/// export this issue exists to remove, so it fails at startup instead.
+///
+/// [ANW-42]: https://crvrs.youtrack.cloud/issue/ANW-42
+fn check_protocols(env: &OtelEnv) -> anyhow::Result<()> {
+    let vars = [
+        ("OTEL_EXPORTER_OTLP_PROTOCOL", env.protocol.as_deref()),
+        (
+            "OTEL_EXPORTER_OTLP_METRICS_PROTOCOL",
+            env.metrics_protocol.as_deref(),
+        ),
+        (
+            "OTEL_EXPORTER_OTLP_TRACES_PROTOCOL",
+            env.traces_protocol.as_deref(),
+        ),
+    ];
+    for (name, value) in vars {
+        let Some(value) = value else { continue };
+        if value != SUPPORTED_PROTOCOL {
+            bail!(
+                "{name}={value:?} is not supported; this build speaks \
+                 {SUPPORTED_PROTOCOL} only. Unset the variable, and point the \
+                 endpoint at the collector's HTTP port rather than its gRPC one"
+            );
+        }
+    }
+    Ok(())
+}
+
+/// The resource attributes anwesen supplies as defaults, minus every key the
+/// environment already sets.
+///
+/// `service.name=anwesen` and the crate version are defaults, not policy:
+/// contract point 6 of [ANW-42] keeps `OTEL_SERVICE_NAME` and
+/// `OTEL_RESOURCE_ATTRIBUTES` working. Attaching them unconditionally blocks
+/// the override, because an attribute set on the builder wins over the one
+/// the SDK's own detectors read from those variables (measured by sie).
+///
+/// Only key presence matters here; the values stay the SDK's to parse.
+///
+/// [ANW-42]: https://crvrs.youtrack.cloud/issue/ANW-42
+fn default_resource_attrs(
+    service_name: Option<&str>,
+    resource_attributes: Option<&str>,
+) -> Vec<KeyValue> {
+    let from_attrs: Vec<&str> = resource_attributes
+        .unwrap_or_default()
+        .split(',')
+        .filter_map(|entry| entry.split_once('='))
+        .map(|(key, _)| key.trim())
+        .collect();
+    let set_by_env = |key: &str| {
+        (key == SERVICE_NAME && service_name.is_some_and(|v| !v.trim().is_empty()))
+            || from_attrs.contains(&key)
+    };
+    [
+        (SERVICE_NAME, "anwesen"),
+        (SERVICE_VERSION, env!("CARGO_PKG_VERSION")),
+    ]
+    .into_iter()
+    .filter(|(key, _)| !set_by_env(key))
+    .map(|(key, value)| KeyValue::new(key, value))
+    .collect()
 }
 
 /// Semantic route bucket for the `http.route` label. Coarser than the axum
@@ -332,28 +480,29 @@ struct TelemetryInner {
 
 impl TelemetryInner {
     fn new(config: TelemetryConfig) -> anyhow::Result<Self> {
-        let TelemetryConfig {
-            endpoint,
-            headers,
-            slow_request,
-        } = config;
-        // `.with_endpoint()` is used verbatim by the exporter (the `/v1/*`
-        // suffix is only auto-appended for the generic OTEL env var), so we
-        // append the per-signal path ourselves.
-        let endpoint = endpoint.trim_end_matches('/').to_string();
-        let header_map: HashMap<String, String> = headers.into_iter().collect();
+        let TelemetryConfig { slow_request, env } = config;
 
-        let resource = Resource::builder()
-            .with_service_name("anwesen")
-            .with_attribute(KeyValue::new(SERVICE_VERSION, env!("CARGO_PKG_VERSION")))
-            .build();
+        // Service identity is a default only: a key OTEL_SERVICE_NAME or
+        // OTEL_RESOURCE_ATTRIBUTES already carries is left to the SDK's own
+        // detectors, because a builder attribute would win over them.
+        let mut resource = Resource::builder();
+        for attr in default_resource_attrs(
+            std::env::var("OTEL_SERVICE_NAME").ok().as_deref(),
+            std::env::var("OTEL_RESOURCE_ATTRIBUTES").ok().as_deref(),
+        ) {
+            resource = resource.with_attribute(attr);
+        }
+        let resource = resource.build();
 
         // -- metrics: thread-based periodic reader over an OTLP/HTTP exporter.
+        // No endpoint, headers, or protocol here: the SDK reads
+        // OTEL_EXPORTER_OTLP_* itself and composes the per-signal URL
+        // (ANW-42). `.with_http()` picks the only transport this binary is
+        // built with, http/protobuf -- the default, and what anwesen sent
+        // before. Any other OTEL_EXPORTER_OTLP_PROTOCOL value would be
+        // ignored here, so `check_protocols` rejects it at startup.
         let metric_exporter = MetricExporter::builder()
             .with_http()
-            .with_protocol(Protocol::HttpBinary)
-            .with_endpoint(format!("{endpoint}/v1/metrics"))
-            .with_headers(header_map.clone())
             .build()
             .context("build OTLP metric exporter")?;
         let reader = PeriodicReader::builder(metric_exporter)
@@ -386,9 +535,6 @@ impl TelemetryInner {
         // -- traces: thread-based batch processor over an OTLP/HTTP exporter.
         let span_exporter = SpanExporter::builder()
             .with_http()
-            .with_protocol(Protocol::HttpBinary)
-            .with_endpoint(format!("{endpoint}/v1/traces"))
-            .with_headers(header_map)
             .build()
             .context("build OTLP span exporter")?;
         let tracer_provider = SdkTracerProvider::builder()
@@ -401,7 +547,7 @@ impl TelemetryInner {
         let tracer = tracer_provider.tracer("anwesen");
 
         tracing::info!(
-            endpoint = %endpoint,
+            endpoint = %env.describe(),
             slow_request_ms = slow_request.as_millis(),
             "telemetry: OTLP export enabled"
         );
@@ -489,93 +635,208 @@ mod tests {
         RawTelemetryArgs::default()
     }
 
-    #[test]
-    fn resolve_off_when_nothing_set() {
-        let cfg = TelemetryConfig::resolve(raw()).unwrap();
-        assert!(cfg.is_none(), "no endpoint/DSN means telemetry off");
+    fn generic(endpoint: &str) -> OtelEnv {
+        OtelEnv {
+            endpoint: Some(endpoint.into()),
+            ..OtelEnv::default()
+        }
     }
 
     #[test]
-    fn resolve_generic_endpoint() {
-        let cfg = TelemetryConfig::resolve(RawTelemetryArgs {
-            otlp_endpoint: Some("https://collector.example.com".into()),
-            otlp_headers: vec!["authorization=Bearer xyz".into()],
-            slow_request_ms: 500,
-            ..raw()
-        })
-        .unwrap()
-        .expect("telemetry on");
-        assert_eq!(cfg.endpoint, "https://collector.example.com");
-        assert_eq!(
-            cfg.headers,
-            vec![("authorization".to_string(), "Bearer xyz".to_string())]
+    fn resolve_off_when_no_endpoint_variable_is_set() {
+        let cfg = TelemetryConfig::resolve(&raw(), OtelEnv::default()).unwrap();
+        assert!(cfg.is_none(), "no OTEL_ endpoint means telemetry off");
+    }
+
+    #[test]
+    fn resolve_on_for_each_endpoint_variable() {
+        let per_signal = |field: fn(&mut OtelEnv)| {
+            let mut env = OtelEnv::default();
+            field(&mut env);
+            env
+        };
+        for env in [
+            generic("https://collector.example.com"),
+            per_signal(|e| {
+                e.metrics_endpoint = Some("https://collector.example.com/v1/metrics".into());
+            }),
+            per_signal(|e| {
+                e.traces_endpoint = Some("https://collector.example.com/v1/traces".into());
+            }),
+        ] {
+            let cfg = TelemetryConfig::resolve(
+                &RawTelemetryArgs {
+                    slow_request_ms: 250,
+                    ..raw()
+                },
+                env.clone(),
+            )
+            .unwrap_or_else(|e| panic!("{env:?}: {e}"))
+            .expect("telemetry on");
+            assert_eq!(cfg.slow_request, Duration::from_millis(250));
+        }
+    }
+
+    /// The tails the SDK mangles: a query lands in the query string with the
+    /// signal path behind it, a fragment drops the signal path entirely.
+    #[test]
+    fn resolve_rejects_a_query_or_fragment_on_the_generic_endpoint() {
+        for endpoint in [
+            "https://api.uptrace.dev?grpc=4317",
+            "https://api.uptrace.dev/?grpc=4317",
+            "https://api.uptrace.dev:4318?grpc=4317",
+            "https://api.uptrace.dev#frag",
+        ] {
+            let err = TelemetryConfig::resolve(&raw(), generic(endpoint)).unwrap_err();
+            assert!(err.to_string().contains("trailing"), "{endpoint}: {err}");
+        }
+    }
+
+    /// A path prefix composes correctly (`/otlp` -> `POST /otlp/v1/metrics`),
+    /// and the per-signal variables are used verbatim, tail and all.
+    #[test]
+    fn resolve_accepts_a_path_prefix_and_per_signal_tails() {
+        for env in [
+            generic("https://collector.example.com/otlp"),
+            generic("https://collector.example.com/"),
+            OtelEnv {
+                metrics_endpoint: Some("https://api.uptrace.dev/v1/metrics?grpc=4317".into()),
+                ..OtelEnv::default()
+            },
+        ] {
+            TelemetryConfig::resolve(&raw(), env.clone())
+                .unwrap_or_else(|e| panic!("{env:?}: {e}"))
+                .expect("telemetry on");
+        }
+    }
+
+    /// `.with_http()` fixes the transport at compile time, so a protocol this
+    /// build cannot speak is a dead export with nothing in the log.
+    #[test]
+    fn resolve_rejects_a_protocol_this_build_cannot_speak() {
+        let with_protocol = |field: fn(&mut OtelEnv)| {
+            let mut env = generic("https://collector.example.com");
+            field(&mut env);
+            env
+        };
+        for env in [
+            with_protocol(|e| e.protocol = Some("grpc".into())),
+            with_protocol(|e| e.protocol = Some("http/json".into())),
+            with_protocol(|e| e.metrics_protocol = Some("grpc".into())),
+            with_protocol(|e| e.traces_protocol = Some("grpc".into())),
+        ] {
+            let err = TelemetryConfig::resolve(&raw(), env.clone())
+                .unwrap_err()
+                .to_string();
+            assert!(err.contains("http/protobuf"), "{env:?}: {err}");
+        }
+    }
+
+    /// The default protocol is the one this build speaks, so naming it
+    /// explicitly is not an error.
+    #[test]
+    fn resolve_accepts_the_supported_protocol_spelled_out() {
+        let env = OtelEnv {
+            protocol: Some("http/protobuf".into()),
+            metrics_protocol: Some("http/protobuf".into()),
+            ..generic("https://collector.example.com")
+        };
+        TelemetryConfig::resolve(&raw(), env)
+            .unwrap()
+            .expect("telemetry on");
+    }
+
+    /// Contract point 6: `service.name` stays anwesen's default only while
+    /// the environment supplies none. A builder attribute wins over the SDK's
+    /// detectors, so the default has to step aside for the override to work.
+    #[test]
+    fn service_identity_defaults_step_aside_for_the_environment() {
+        let keys = |attrs: &[KeyValue]| {
+            attrs
+                .iter()
+                .map(|kv| kv.key.as_str().to_string())
+                .collect::<Vec<_>>()
+        };
+
+        let plain = default_resource_attrs(None, None);
+        assert_eq!(keys(&plain), [SERVICE_NAME, SERVICE_VERSION]);
+
+        let named = default_resource_attrs(Some("svcname-override"), None);
+        assert_eq!(keys(&named), [SERVICE_VERSION]);
+
+        let attrs = default_resource_attrs(
+            None,
+            Some("deployment.environment=prod,service.name=attrs-override"),
         );
-        assert_eq!(cfg.slow_request, Duration::from_millis(500));
+        assert_eq!(keys(&attrs), [SERVICE_VERSION]);
+
+        let versioned = default_resource_attrs(None, Some("service.version=9.9.9"));
+        assert_eq!(keys(&versioned), [SERVICE_NAME]);
+
+        // An empty OTEL_SERVICE_NAME supplies nothing; the SDK ignores it too.
+        let empty = default_resource_attrs(Some("  "), None);
+        assert_eq!(keys(&empty), [SERVICE_NAME, SERVICE_VERSION]);
     }
 
     #[test]
-    fn resolve_uptrace_dsn_splits_endpoint_and_header() {
-        let cfg = TelemetryConfig::resolve(RawTelemetryArgs {
-            uptrace_dsn: Some("https://SECRET_TOKEN@api.uptrace.dev".into()),
-            slow_request_ms: 250,
-            ..raw()
-        })
-        .unwrap()
-        .expect("telemetry on");
-        assert_eq!(cfg.endpoint, "https://api.uptrace.dev");
-        assert_eq!(
-            cfg.headers,
-            vec![(
-                "uptrace-dsn".to_string(),
-                "https://SECRET_TOKEN@api.uptrace.dev".to_string()
-            )]
-        );
-        assert_eq!(cfg.slow_request, Duration::from_millis(250));
+    fn resolve_rejects_the_removed_uptrace_dsn() {
+        let err = TelemetryConfig::resolve(
+            &RawTelemetryArgs {
+                uptrace_dsn: Some("https://tok@api.uptrace.dev".into()),
+                ..raw()
+            },
+            OtelEnv::default(),
+        )
+        .unwrap_err()
+        .to_string();
+        assert!(err.contains("--uptrace-dsn"), "{err}");
+        assert!(err.contains("OTEL_EXPORTER_OTLP_HEADERS"), "{err}");
     }
 
     #[test]
-    fn resolve_dsn_header_leads_explicit_headers() {
-        let cfg = TelemetryConfig::resolve(RawTelemetryArgs {
-            uptrace_dsn: Some("https://tok@api.uptrace.dev".into()),
-            otlp_headers: vec!["x-extra=1".into()],
-            ..raw()
-        })
-        .unwrap()
-        .expect("telemetry on");
-        assert_eq!(cfg.headers[0].0, "uptrace-dsn");
-        assert_eq!(cfg.headers[1], ("x-extra".to_string(), "1".to_string()));
+    fn resolve_rejects_the_removed_otlp_endpoint() {
+        let err = TelemetryConfig::resolve(
+            &RawTelemetryArgs {
+                otlp_endpoint: Some("https://collector.example.com".into()),
+                ..raw()
+            },
+            OtelEnv::default(),
+        )
+        .unwrap_err()
+        .to_string();
+        assert!(err.contains("--otlp-endpoint"), "{err}");
+        assert!(err.contains("OTEL_EXPORTER_OTLP_ENDPOINT"), "{err}");
     }
 
     #[test]
-    fn resolve_rejects_both_endpoint_sources() {
-        let err = TelemetryConfig::resolve(RawTelemetryArgs {
-            uptrace_dsn: Some("https://tok@api.uptrace.dev".into()),
-            otlp_endpoint: Some("https://collector.example.com".into()),
-            ..raw()
-        })
+    fn resolve_rejects_the_removed_otlp_header() {
+        let err = TelemetryConfig::resolve(
+            &RawTelemetryArgs {
+                otlp_headers: vec!["authorization=Bearer xyz".into()],
+                ..raw()
+            },
+            OtelEnv::default(),
+        )
+        .unwrap_err()
+        .to_string();
+        assert!(err.contains("--otlp-header"), "{err}");
+        assert!(err.contains("OTEL_EXPORTER_OTLP_HEADERS"), "{err}");
+    }
+
+    /// A removed option fails even with a correct `OTEL_` endpoint alongside
+    /// it: the operator's intent is in the flag, and half-applied config is
+    /// the silent failure this issue removes.
+    #[test]
+    fn resolve_rejects_a_removed_option_alongside_a_good_endpoint() {
+        let err = TelemetryConfig::resolve(
+            &RawTelemetryArgs {
+                uptrace_dsn: Some("https://tok@api.uptrace.dev".into()),
+                ..raw()
+            },
+            generic("https://api.uptrace.dev"),
+        )
         .unwrap_err();
-        assert!(err.to_string().contains("mutually exclusive"));
-    }
-
-    #[test]
-    fn resolve_rejects_malformed_header() {
-        let err = TelemetryConfig::resolve(RawTelemetryArgs {
-            otlp_endpoint: Some("https://collector.example.com".into()),
-            otlp_headers: vec!["no-equals-sign".into()],
-            ..raw()
-        })
-        .unwrap_err();
-        assert!(err.to_string().contains("key=value"));
-    }
-
-    #[test]
-    fn resolve_rejects_dsn_without_scheme() {
-        let err = TelemetryConfig::resolve(RawTelemetryArgs {
-            uptrace_dsn: Some("tok@api.uptrace.dev".into()),
-            ..raw()
-        })
-        .unwrap_err();
-        assert!(err.to_string().contains("scheme"));
+        assert!(err.to_string().contains("removed"), "{err}");
     }
 
     #[test]
diff --git a/src/watcher.rs b/src/watcher.rs
index f004db0..0f7ccc0 100644
--- a/src/watcher.rs
+++ b/src/watcher.rs
@@ -4,7 +4,7 @@
 //! [`notify::RecommendedWatcher`] over the vault root. Each native event is
 //! pushed into a Tokio channel; [`run_debouncer`] drains the channel,
 //! classifies events into [`WatchAction`]s, coalesces a 100 ms window's
-//! worth into one [`Batch`], and casts the batch to the `index_writer`
+//! worth into one [`WatchBatch`], and casts the batch to the `index_writer`
 //! named process for a single [`crate::store::NoteStore`] write.
 //!
 //! See [[ADR-003 Filesystem Change Tracking]] for the event model.
@@ -27,7 +27,7 @@ use crate::vault;
 
 /// One path-scoped action derived from a native filesystem event. Always
 /// carries a vault-relative, forward-slash-normalized path string -- the
-/// same form [`vault::Note.path`] uses.
+/// same form [`vault::Note::path`] uses.
 ///
 /// The `*Tree` variants carry a directory instead of a note. Native events
 /// name only the directory when one is created, removed, or renamed; the
diff --git a/tests/run-hurl.sh b/tests/run-hurl.sh
index d64c841..4700b78 100755
--- a/tests/run-hurl.sh
+++ b/tests/run-hurl.sh
@@ -54,6 +54,20 @@ if [[ $ready -ne 1 ]]; then
     exit 1
 fi
 
+# ANW-43: the offline `query` subcommand must return the document the endpoint
+# returns. Both surfaces read the same fixture vault, so the two outputs are
+# compared byte for byte before the contract suite runs.
+for q in "" "tags=project" "__anw-path=Projects&__anw-limit=1" "status__exists=true"; do
+    cli="$("$BIN" query --vault "$VAULT" --query "$q" --log-level error)"
+    http="$(curl -sf "http://$HOST:$PORT/query?$q")"
+    if [[ "$cli" != "$http" ]]; then
+        echo "anwesen query and GET /query disagree for query '$q'" >&2
+        echo "  cli:  $cli" >&2
+        echo "  http: $http" >&2
+        exit 1
+    fi
+done
+
 # Run every *.hurl. Glob into an array so we can fail loud if there are none.
 shopt -s globstar nullglob
 files=("$ROOT"/tests/hurl/**/*.hurl)
diff --git a/tests/serve_start_failure.rs b/tests/serve_start_failure.rs
new file mode 100644
index 0000000..4c01948
--- /dev/null
+++ b/tests/serve_start_failure.rs
@@ -0,0 +1,33 @@
+//! `anwesen serve` must exit nonzero when the supervisor tree fails to start
+//! ([ANW-45](https://crvrs.youtrack.cloud/issue/ANW-45)). Hydra's
+//! `Application::run` logs the failure and returns normally, so without an
+//! explicit check the process exits 0 and systemd's `Restart=on-failure`
+//! never retries -- the vault stayed unreachable for 12 hours on ap.
+//!
+//! The forced failure is a taken bind address: `http_server` binds eagerly in
+//! its child spec, so the address-in-use error fails the whole start.
+
+use std::net::TcpListener;
+use std::process::Command;
+
+#[test]
+fn serve_exits_nonzero_when_the_tree_fails_to_start() {
+    let vault = tempfile::tempdir().expect("tempdir");
+    // Hold the port for the lifetime of the child so its bind cannot succeed.
+    let held = TcpListener::bind("127.0.0.1:0").expect("bind probe port");
+    let addr = held.local_addr().expect("probe addr");
+
+    let status = Command::new(env!("CARGO_BIN_EXE_anwesen"))
+        .arg("serve")
+        .arg("--vault")
+        .arg(vault.path())
+        .arg("--bind")
+        .arg(addr.to_string())
+        .status()
+        .expect("spawn anwesen serve");
+
+    assert!(
+        !status.success(),
+        "serve exited {status} after a failed supervisor start; systemd reads that as a clean exit"
+    );
+}