diff --git a/.github/CODEOWNERS b/.github/CODEOWNERS
new file mode 100644
index 0000000..bf52060
--- /dev/null
+++ b/.github/CODEOWNERS
@@ -0,0 +1,16 @@
+# Code owners for goceleris/loadgen.
+#
+# GitHub requests a review from the matching owners on every pull request
+# that touches these paths; with "Require review from Code Owners" enabled on
+# the main branch protection, their approval is mandatory before merging.
+# Later rules take precedence over earlier ones — keep the catch-all first.
+#
+# Syntax: https://docs.github.com/articles/about-code-owners
+
+# Default owner for everything in the repository.
+* @FumingPower3925
+
+# Area delegation example — uncomment and adjust when a second maintainer
+# takes ownership of a subsystem (the more specific rule wins):
+# /cmd/loadgen/ @FumingPower3925 @WdnLiu
+# /.github/     @FumingPower3925
diff --git a/.github/PULL_REQUEST_TEMPLATE.md b/.github/PULL_REQUEST_TEMPLATE.md
new file mode 100644
index 0000000..1ed0005
--- /dev/null
+++ b/.github/PULL_REQUEST_TEMPLATE.md
@@ -0,0 +1,16 @@
+## Summary
+
+Brief description of the change and why it is needed.
+
+## Changes
+
+-
+
+## Test Plan
+
+- [ ] Unit tests added/updated (`go test -race -count=1 ./...`)
+- [ ] `golangci-lint run` and `go vet ./...` pass
+- [ ] Integration matrix passes if the H1/H2/WS/SSE client paths changed (`go test -tags integration -run TestIntegrationH2CMatrix .`)
+- [ ] README cluster-bench contract updated if the JSON result schema or CLI flags changed
+
+Closes #
diff --git a/.github/release.yml b/.github/release.yml
new file mode 100644
index 0000000..556d91b
--- /dev/null
+++ b/.github/release.yml
@@ -0,0 +1,31 @@
+# Automatically generated release notes (GitHub "Generate release notes").
+# Same categories as goceleris/celeris so the org's release pages read alike.
+# Labels are applied on the pull request; dependabot / actions bumps are
+# excluded because they are noise for consumers of the binaries.
+changelog:
+  exclude:
+    labels:
+      - dependencies
+      - github_actions
+  categories:
+    - title: Breaking Changes
+      labels:
+        - breaking
+    - title: Security
+      labels:
+        - security
+    - title: Fixes
+      labels:
+        - bug
+        - fix
+    - title: Performance
+      labels:
+        - performance
+        - perf
+    - title: Features
+      labels:
+        - enhancement
+        - feature
+    - title: Other Changes
+      labels:
+        - "*"
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1d4d2b6..e189cbf 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -14,11 +14,13 @@ jobs:
     name: Lint
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v7
-      - uses: actions/setup-go@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+      - uses: actions/setup-go@b7ad1dad31e06c5925ef5d2fc7ad053ef454303e # v7.0.0
         with:
           go-version: "1.27.0"
-      - uses: golangci/golangci-lint-action@v9
+      - uses: golangci/golangci-lint-action@ba0d7d2ec06a0ea1cb5fa41b2e4a3ab91d21278a # v9.3.0
         with:
           version: v2.13
       - name: actionlint
@@ -33,8 +35,10 @@ jobs:
     name: Test
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v7
-      - uses: actions/setup-go@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+      - uses: actions/setup-go@b7ad1dad31e06c5925ef5d2fc7ad053ef454303e # v7.0.0
         with:
           go-version: "1.27.0"
       - name: Run tests
@@ -45,8 +49,10 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 5
     steps:
-      - uses: actions/checkout@v7
-      - uses: actions/setup-go@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+      - uses: actions/setup-go@b7ad1dad31e06c5925ef5d2fc7ad053ef454303e # v7.0.0
         with:
           go-version: "1.27.0"
       # The testserver helper imports github.com/goceleris/celeris (pinned in
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 71a04f6..c8f14de 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -12,8 +12,10 @@ jobs:
     name: Publish to Go Package Registry
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v7
-      - uses: actions/setup-go@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+      - uses: actions/setup-go@b7ad1dad31e06c5925ef5d2fc7ad053ef454303e # v7.0.0
         with:
           go-version: "1.27.0"
       - name: Verify module
@@ -33,6 +35,10 @@ jobs:
     # orchestrators can fetch them without re-cloning + rebuilding.
     name: Build cmd/loadgen binaries (${{ matrix.goos }}/${{ matrix.goarch }})
     runs-on: ubuntu-latest
+    permissions:
+      contents: write       # action-gh-release uploads the tarball to the release
+      id-token: write       # OIDC token that signs the SLSA provenance (Sigstore)
+      attestations: write   # store the attestation in the repository's attestation store
     strategy:
       matrix:
         include:
@@ -45,8 +51,8 @@ jobs:
           - goos: darwin
             goarch: arm64
     steps:
-      - uses: actions/checkout@v7
-      - uses: actions/setup-go@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: actions/setup-go@b7ad1dad31e06c5925ef5d2fc7ad053ef454303e # v7.0.0
         with:
           go-version: "1.27.0"
       - name: Build
@@ -67,7 +73,13 @@ jobs:
         run: |
           cd dist
           tar czf "loadgen_${GOOS}_${GOARCH}.tar.gz" "loadgen-${GOOS}-${GOARCH}"
+      # SLSA build provenance for the exact archive that ships. Consumers
+      # verify with: gh attestation verify <asset> -R goceleris/loadgen
+      - name: Attest build provenance
+        uses: actions/attest-build-provenance@4d101475d8b20a2381f78447822ac1eab6504dd8 # v4.2.2
+        with:
+          subject-path: dist/loadgen_${{ matrix.goos }}_${{ matrix.goarch }}.tar.gz
       - name: Attach to release
-        uses: softprops/action-gh-release@v3
+        uses: softprops/action-gh-release@efb35369e0ad2afab669f228072c1b0d510eae64 # v3.0.3
         with:
           files: dist/loadgen_${{ matrix.goos }}_${{ matrix.goarch }}.tar.gz
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000..f3e2718
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,66 @@
+# Contributing to loadgen
+
+Thanks for helping improve loadgen, the load generator behind the celeris
+benchmark suite. loadgen is deliberately dependency-light (two direct Go
+dependencies) and is exercised on real hardware by
+[goceleris/probatorium](https://github.com/goceleris/probatorium), so
+changes are held to the same standard as the engine they measure.
+
+## Prerequisites
+
+- Go **1.27.0** (the version pinned in `go.mod` and in CI)
+- [golangci-lint](https://golangci-lint.run/) v2.13+ (the CI pin)
+- Linux or macOS. The client itself is portable; the process-CPU sampler
+  and recv-queue probe have Linux implementations and `_other.go`
+  fallbacks.
+
+## Build and test
+
+```bash
+go build ./...                                   # compile everything, including cmd/loadgen
+go vet ./...
+golangci-lint run                                # same config CI uses (.golangci.yml)
+go test -race -count=1 -timeout 120s ./...       # unit tests, exactly as CI runs them
+
+# Integration matrix against a live celeris server. The testserver helper is
+# a nested module that imports celeris; the tests spawn it as a subprocess.
+go test -tags integration -race -count=1 -timeout 180s -v -run TestIntegrationH2CMatrix .
+```
+
+`gofmt` and `goimports` (with `github.com/goceleris/loadgen` as the local
+prefix) are enforced by golangci-lint, so run it before pushing.
+
+## Pull request flow
+
+1. Fork the repository and create a topic branch from `main`
+   (`feat/…`, `fix/…`, `perf/…`, `chore/…`).
+2. Keep each PR focused on a single change and include tests — a
+   correctness fix without a regression test is not complete.
+3. Write commit messages in the `type: description` format
+   (`feat:`, `fix:`, `perf:`, `security:`, `test:`, `ci:`, `docs:`, `chore:`)
+   and explain *why* in the body when it is not obvious from the diff.
+4. Fill in the pull request template (Summary, Changes, Test Plan,
+   `Closes #…`). Changes to the JSON result schema or the CLI flags must
+   also update the README's cluster-bench contract section, because
+   probatorium parses that output.
+5. Make sure the CI workflow (lint, actionlint, unit tests, integration
+   matrix) is green.
+
+## Merge rule
+
+loadgen follows the same governance as celeris — see
+[celeris/GOVERNANCE.md](https://github.com/goceleris/celeris/blob/main/GOVERNANCE.md).
+In short: `main` is protected, every change lands through a pull request
+that passes CI and is approved by a code owner (see `.github/CODEOWNERS`),
+and pull requests are merged by a maintainer — never force-pushed. Releases
+are tagged from `main` and the release workflow builds, attests and
+publishes the binaries.
+
+## Reporting security issues
+
+Do not open a public issue. Follow [SECURITY.md](SECURITY.md).
+
+## License
+
+By contributing you agree that your contributions are licensed under the
+[Apache License 2.0](LICENSE) that covers the project.
diff --git a/README.md b/README.md
index ecc7a7c..4252caf 100644
--- a/README.md
+++ b/README.md
@@ -328,6 +328,16 @@ chmod +x /tmp/loadgen-${OS}-${ARCH}
 
 GitHub displays the SHA-256 of each release asset on the release page — `gh release download <tag>` and the web UI verify checksums automatically, so no separate `.sha256` sidecar ships.
 
+### Verify a release
+
+Every release tarball is built by the [release workflow](.github/workflows/release.yml) and carries a signed [SLSA build provenance](https://slsa.dev/provenance/) attestation, generated with `actions/attest-build-provenance` and recorded in GitHub's attestation store. Before running a downloaded binary on a bench host, check that the asset really came from this repository's release pipeline:
+
+```bash
+gh attestation verify loadgen_linux_amd64.tar.gz -R goceleris/loadgen
+```
+
+The command fails if the archive was tampered with after the build or was not produced by a `goceleris/loadgen` workflow. Add `--format json` to inspect the attested source commit, workflow path and builder. Releases published before the attestation step was added (v1.4.13 and earlier) have no attestation and will fail verification.
+
 ### Reference orchestrator
 
 The probatorium cluster bench drives this contract: it cross-compiles loadgen (or fetches a release tarball), pushes it to the load host, executes it, and parses the stdout JSON — decoding `histogram` for cross-cell re-aggregation. See [goceleris/probatorium](https://github.com/goceleris/probatorium).
diff --git a/SECURITY.md b/SECURITY.md
new file mode 100644
index 0000000..6f68a87
--- /dev/null
+++ b/SECURITY.md
@@ -0,0 +1,60 @@
+# Security Policy
+
+loadgen is a load-generation *client*: it opens outbound connections to a
+target you name on the command line and never listens on a socket in
+production use. Its security surface is therefore small — a malicious
+server could still try to exploit the HTTP/1.1, HTTP/2, WebSocket and SSE
+response parsers, and the JSON result written to stdout is consumed by
+orchestrators — so we treat parser and output-handling bugs as security
+issues.
+
+## Reporting a Vulnerability
+
+**Please do not open a public issue for security problems.**
+
+Report privately, in order of preference:
+
+1. **GitHub private vulnerability reporting (preferred)** — open the
+   repository's **Security** tab and click **"Report a vulnerability"**.
+   Private vulnerability reporting is enabled on this repository; the report
+   is visible only to the maintainers and becomes the draft advisory that
+   ships with the fix.
+2. **Email** — [security@goceleris.dev](mailto:security@goceleris.dev).
+
+Include a description of the issue, the loadgen version (the release tag, or
+the `loadgen_version` field of a result), reproduction steps or a
+proof-of-concept, and the impact you believe it has.
+
+You will receive an **acknowledgement within 72 hours**. We will keep you
+informed as we triage, fix and disclose, and we credit reporters in the
+release notes unless they prefer otherwise.
+
+## Supported Versions
+
+Only the latest release of loadgen receives security fixes. Pre-built
+binaries and the Go module are cut from the same tag, so upgrade to the most
+recent `v1.x` tag to remain covered.
+
+## Scope
+
+In scope:
+
+- The HTTP/1.1, HTTP/2 (prior-knowledge and h2c upgrade), WebSocket and SSE
+  client implementations and their response parsers
+- TLS configuration handling (`-insecure`, custom `tls.Config`)
+- The federation peer protocol
+- The JSON result output consumed by orchestrators
+- The release pipeline (workflows, published binaries and their provenance)
+
+Out of scope:
+
+- Vulnerabilities in the server under test
+- Denial of service of a target caused by *intended* use of a load generator
+
+## The celeris engine
+
+Vulnerabilities in the HTTP server framework that loadgen is built to test
+belong to the [goceleris/celeris](https://github.com/goceleris/celeris)
+repository — see
+[celeris/SECURITY.md](https://github.com/goceleris/celeris/blob/main/SECURITY.md)
+for its supported-versions table and reporting channels.