feat(version): bake git-sha + build-date; add --json to status and version subcommand

Cargo.toml

@@ -9,6 +9,7 @@ license-file = "LICENSE"
 repository = "https://github.com/hyperpolymath/verisimiser"
 keywords = ["verisim", "database", "augmentation", "drift-detection", "provenance"]
 categories = ["command-line-utilities", "database"]
+build = "build.rs"
 
 [dependencies]
 clap = { version = "4", features = ["derive"] }
@@ -20,5 +21,8 @@ thiserror = "2"
 chrono = { version = "0.4", features = ["serde"] }
 sha2 = "0.10"
 
+[build-dependencies]
+chrono = "0.4"
+
 [dev-dependencies]
 tempfile = "3"

build.rs

@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: PMPL-1.0-or-later
+// Copyright (c) 2026 Jonathan D.A. Jewell (hyperpolymath) <j.d.a.jewell@open.ac.uk>
+//
+// Emit git-sha + build-date as compile-time env vars so the binary can show
+// them in `verisimiser --version` and `verisimiser version --json`.
+// Closes #56 (V-L3-J1). No build-dep — uses the `git` CLI and `chrono` is
+// available at runtime via the main dependency tree.
+
+use std::process::Command;
+
+fn main() {
+    let sha = Command::new("git")
+        .args(["rev-parse", "--short=12", "HEAD"])
+        .output()
+        .ok()
+        .filter(|o| o.status.success())
+        .and_then(|o| String::from_utf8(o.stdout).ok())
+        .map(|s| s.trim().to_string())
+        .unwrap_or_else(|| "unknown".to_string());
+
+    let describe = Command::new("git")
+        .args(["describe", "--tags", "--always", "--dirty"])
+        .output()
+        .ok()
+        .filter(|o| o.status.success())
+        .and_then(|o| String::from_utf8(o.stdout).ok())
+        .map(|s| s.trim().to_string())
+        .unwrap_or_else(|| "unknown".to_string());
+
+    let build_date = chrono::Utc::now().format("%Y-%m-%d").to_string();
+
+    println!("cargo:rustc-env=VERISIMISER_GIT_SHA={}", sha);
+    println!("cargo:rustc-env=VERISIMISER_GIT_DESCRIBE={}", describe);
+    println!("cargo:rustc-env=VERISIMISER_BUILD_DATE={}", build_date);
+
+    // Re-run when HEAD moves or git ref changes.
+    println!("cargo:rerun-if-changed=.git/HEAD");
+    println!("cargo:rerun-if-changed=.git/refs");
+}

src/main.rs

@@ -19,9 +19,19 @@ use anyhow::Result;
 use clap::{Parser, Subcommand};
 use verisimiser::{abi, codegen, manifest};
 
+/// Long version string: `<crate-version> (<git-describe>, built <date>)`.
+const LONG_VERSION: &str = concat!(
+    env!("CARGO_PKG_VERSION"),
+    " (",
+    env!("VERISIMISER_GIT_DESCRIBE"),
+    ", built ",
+    env!("VERISIMISER_BUILD_DATE"),
+    ")",
+);
+
 /// VeriSimiser — augment any database with VeriSimDB octad capabilities.
 #[derive(Parser)]
-#[command(name = "verisimiser", version, about, long_about = None)]
+#[command(name = "verisimiser", version = LONG_VERSION, about, long_about = None)]
 struct Cli {
     #[command(subcommand)]
     command: Commands,
@@ -85,9 +95,18 @@ enum Commands {
     Status {
         #[arg(short, long, default_value = "verisimiser.toml")]
         manifest: String,
+        /// Emit a structured JSON report instead of human-readable text.
+        #[arg(long)]
+        json: bool,
     },
     /// Show the octad modalities and which tiers they belong to.
     Octad,
+    /// Print version, git-sha, and build-date.
+    Version {
+        /// Emit JSON instead of human-readable text.
+        #[arg(long)]
+        json: bool,
+    },
 }
 
 fn main() -> Result<()> {
@@ -189,16 +208,36 @@ fn main() -> Result<()> {
             Ok(())
         }
 
-        Commands::Status { manifest } => {
+        Commands::Status { manifest, json } => {
             let m = manifest::load_manifest(&manifest)?;
-            manifest::print_status(&m);
+            if json {
+                let report = manifest::status_report(&m);
+                println!("{}", serde_json::to_string_pretty(&report)?);
+            } else {
+                manifest::print_status(&m);
+            }
             Ok(())
         }
 
         Commands::Octad => {
             print_octad();
             Ok(())
         }
+
+        Commands::Version { json } => {
+            if json {
+                let report = serde_json::json!({
+                    "version": env!("CARGO_PKG_VERSION"),
+                    "git_sha": env!("VERISIMISER_GIT_SHA"),
+                    "git_describe": env!("VERISIMISER_GIT_DESCRIBE"),
+                    "build_date": env!("VERISIMISER_BUILD_DATE"),
+                });
+                println!("{}", serde_json::to_string_pretty(&report)?);
+            } else {
+                println!("{}", LONG_VERSION);
+            }
+            Ok(())
+        }
     }
 }
 

src/manifest/mod.rs

@@ -466,6 +466,72 @@ mod init_template_tests {
     }
 }
 
+/// Documented JSON schema returned by `verisimiser status --json`.
+///
+/// Field stability: `name`, `backend`, `sidecar_path`, `sidecar_storage`,
+/// and `octad` are part of the public schema. New fields may be added
+/// in minor versions; existing fields will not be removed without a
+/// major version bump.
+#[derive(Debug, Clone, Serialize)]
+pub struct StatusReport {
+    /// Project name (`[project].name` or legacy `[verisimiser].name`).
+    pub name: String,
+    /// Effective database backend after legacy field resolution.
+    pub backend: String,
+    /// Path to the sidecar storage file.
+    pub sidecar_path: String,
+    /// Sidecar storage technology.
+    pub sidecar_storage: String,
+    /// Per-dimension enablement.
+    pub octad: OctadStatus,
+}
+
+/// Per-dimension boolean view used by `StatusReport`.
+#[derive(Debug, Clone, Serialize)]
+pub struct OctadStatus {
+    /// Number of enabled dimensions (always in `2..=8`).
+    pub enabled_count: usize,
+    /// Always `true`.
+    pub data: bool,
+    /// Always `true`.
+    pub metadata: bool,
+    pub provenance: bool,
+    pub lineage: bool,
+    pub constraints: bool,
+    pub access_control: bool,
+    pub temporal: bool,
+    pub simulation: bool,
+}
+
+/// Build a [`StatusReport`] from a loaded manifest.
+///
+/// Used by `verisimiser status --json`. The same content is rendered as
+/// plain text by [`print_status`].
+pub fn status_report(manifest: &Manifest) -> StatusReport {
+    let name = if !manifest.project.name.is_empty() {
+        manifest.project.name.clone()
+    } else {
+        manifest.verisimiser.name.clone()
+    };
+    StatusReport {
+        name,
+        backend: manifest.database.effective_backend().to_string(),
+        sidecar_path: manifest.sidecar.path.clone(),
+        sidecar_storage: manifest.sidecar.storage.clone(),
+        octad: OctadStatus {
+            enabled_count: manifest.octad.enabled_count(),
+            data: true,
+            metadata: true,
+            provenance: manifest.octad.enable_provenance,
+            lineage: manifest.octad.enable_lineage,
+            constraints: manifest.octad.enable_constraints,
+            access_control: manifest.octad.enable_access_control,
+            temporal: manifest.octad.enable_temporal,
+            simulation: manifest.octad.enable_simulation,
+        },
+    }
+}
+
 /// Print a human-readable status summary of a loaded manifest.
 pub fn print_status(manifest: &Manifest) {
     let name = if !manifest.project.name.is_empty() {