diff --git a/.github/FUNDING.yml b/.github/FUNDING.yml
new file mode 100644
index 0000000..fedc5dd
--- /dev/null
+++ b/.github/FUNDING.yml
@@ -0,0 +1,3 @@
+# Displays the "Sponsor" button on this repository.
+# https://docs.github.com/en/repositories/managing-your-repositorys-settings-and-features/customizing-your-repository/displaying-a-sponsor-button-in-your-repository
+github: [ix-infrastructure]
diff --git a/.github/scripts/copyright-headers.py b/.github/scripts/copyright-headers.py
new file mode 100644
index 0000000..4e7eb4a
--- /dev/null
+++ b/.github/scripts/copyright-headers.py
@@ -0,0 +1,156 @@
+# Copyright 2026 Ix Infrastructure Inc.
+
+"""Enforce the Ix Infrastructure copyright header on every source file.
+
+    python3 .github/scripts/copyright-headers.py           # check, exit 1 on misses
+    python3 .github/scripts/copyright-headers.py --fix      # insert the missing ones
+
+Run from the repository root. CI runs the check; contributors run --fix.
+
+Deliberately NOT covered, because a header there is wrong rather than missing:
+  * test fixtures — parser tests snapshot their output including line numbers,
+    so a header shifts every symbol down a line and breaks them;
+  * anything the repo marks linguist-generated in .gitattributes — regenerated
+    by tooling (the header would be clobbered) or vendored from upstream, whose
+    copyright is not ours to claim;
+  * committed build output and dependencies (dist/, node_modules/, ...).
+
+A file type absent from the tables below is not checked. Adding a language to
+the repo means adding its comment syntax here.
+"""
+
+import os
+import re
+import subprocess
+import sys
+
+HEADER = "Copyright 2026 Ix Infrastructure Inc."
+
+SLASH = {".ts", ".tsx", ".mts", ".cts", ".mjs", ".cjs", ".js", ".jsx", ".scala", ".sc",
+         ".java", ".go", ".rs", ".c", ".h", ".cc", ".cpp", ".hpp", ".swift", ".kt"}
+HASH = {".sh", ".bash", ".zsh", ".ps1", ".psm1", ".py", ".rb", ".pl"}
+CMD = {".cmd", ".bat"}
+
+EXCLUDE_RE = re.compile(
+    r"(^|/)(node_modules|dist|build|out|target|vendor|third_party|\.yarn|coverage)(/|$)"
+    r"|(^|/)(test-)?fixtures?(/|$)"
+    r"|(^|/)__fixtures__(/|$)"
+    r"|\.min\.(js|mjs|cjs)$"
+    r"|\.d\.ts$"
+)
+
+SHEBANG_RE = re.compile(r"^#!")
+CODING_RE = re.compile(r"^#.*coding[:=]")
+ECHOOFF_RE = re.compile(r"^\s*@echo\s+off", re.I)
+
+
+def comment(ext):
+    if ext in SLASH:
+        return "// " + HEADER
+    if ext in HASH:
+        return "# " + HEADER
+    if ext in CMD:
+        return "@REM " + HEADER
+    return None
+
+
+def tracked_files():
+    out = subprocess.run(["git", "ls-files"], capture_output=True, text=True, check=True).stdout
+    return [p for p in out.splitlines() if p]
+
+
+def linguist_generated(paths):
+    """Files the repo itself declares generated. Let git do the glob matching."""
+    if not paths:
+        return set()
+    proc = subprocess.run(["git", "check-attr", "--stdin", "linguist-generated"],
+                          input="\n".join(paths), capture_output=True, text=True)
+    return {line.rsplit(": linguist-generated:", 1)[0]
+            for line in proc.stdout.splitlines() if line.endswith(": set")}
+
+
+def insert_at(lines, ext):
+    """Index the header goes at, keeping order-sensitive first lines in place."""
+    if not lines:
+        return 0
+    if ext in CMD:
+        # `@echo off` must stay first or the REM echoes to the console
+        return 1 if ECHOOFF_RE.match(lines[0]) else 0
+    if SHEBANG_RE.match(lines[0]):
+        if ext == ".py" and len(lines) > 1 and CODING_RE.match(lines[1]):
+            return 2
+        return 1
+    if ext == ".py" and CODING_RE.match(lines[0]):
+        return 1
+    return 0
+
+
+def main(fix):
+    files = tracked_files()
+    generated = linguist_generated(files)
+    missing, wrong = [], []
+
+    for rel in files:
+        ext = os.path.splitext(rel)[1]
+        line = comment(ext)
+        if line is None or EXCLUDE_RE.search(rel) or rel in generated:
+            continue
+        if not os.path.isfile(rel) or os.path.islink(rel):
+            continue
+        with open(rel, "r", encoding="utf-8", errors="surrogateescape", newline="") as fh:
+            text = fh.read()
+        if not text.strip():
+            continue
+        lines = text.split("\n")
+        head = [candidate.rstrip("\r").rstrip() for candidate in lines[:5]]
+        if line in head:
+            continue
+        if any("Copyright" in candidate for candidate in head):
+            # A copyright line, but not ours verbatim — a stale spelling of the
+            # entity, or someone else's claim. Never auto-"fixed": inserting a
+            # second header would leave the file asserting two owners.
+            wrong.append(rel)
+            continue
+        missing.append(rel)
+        if fix:
+            nl_crlf = "\r\n" in text.split("\n", 1)[0] + "\n"
+            block = [line, ""]
+            if nl_crlf:
+                block = [b + "\r" for b in block]
+            at = insert_at([candidate.rstrip("\r") for candidate in lines], ext)
+            lines[at:at] = block
+            with open(rel, "w", encoding="utf-8", errors="surrogateescape", newline="") as fh:
+                fh.write("\n".join(lines))
+
+    if not missing and not wrong:
+        print(f"All source files carry the header: {HEADER}")
+        return 0
+
+    if wrong:
+        print(f"{len(wrong)} source file(s) carry a copyright line that is not"
+              f' exactly "{HEADER}":\n')
+        for w in wrong:
+            print(f"  {w}")
+        print("\nFix these by hand — --fix will not touch them, because inserting a"
+              "\nsecond header would leave the file naming two owners.\n")
+
+    if missing:
+        if fix:
+            print(f"Added the header to {len(missing)} file(s):")
+            for m in missing:
+                print(f"  {m}")
+        else:
+            print(f"{len(missing)} source file(s) are missing the copyright header:\n")
+            for m in missing:
+                print(f"  {m}")
+            print(f'\nEvery source file must start with "{HEADER}"'
+                  " in that language's comment syntax.\nFix them all with:\n"
+                  "\n    python3 .github/scripts/copyright-headers.py --fix\n")
+
+    if fix and not wrong:
+        return 0
+    return 1
+
+
+if __name__ == "__main__":
+    sys.exit(main("--fix" in sys.argv))
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6e99c53..6655d3e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -30,6 +30,14 @@ jobs:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: false
+
+      # Every source file must carry the copyright line. In this job rather than
+      # a workflow of its own: the ruleset requires exactly one status check,
+      # `CI Passed`, and `test` is in its `needs` — a check in any other
+      # workflow reports on the PR and gates nothing. Toolchain-free (stdlib
+      # python3 is preinstalled; the script shells out only to git).
+      - name: Copyright headers on every source file
+        run: python3 .github/scripts/copyright-headers.py
       - uses: oven-sh/setup-bun@0c5077e51419868618aeaa5fe8019c62421857d6 # v2.2.0
         with:
           bun-version: latest
diff --git a/LICENSE b/LICENSE
index 261eeb9..4e9ddc4 100644
--- a/LICENSE
+++ b/LICENSE
@@ -186,7 +186,7 @@
       same "printed page" as the copyright notice for easier
       identification within third-party archives.
 
-   Copyright [yyyy] [name of copyright owner]
+   Copyright 2026 Ix Infrastructure Inc.
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
diff --git a/README.md b/README.md
index 0275d6f..731573e 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,7 @@
 # ix-opencode-plugin
 
+[![Sponsor](https://img.shields.io/badge/sponsor-%E2%9D%A4-db61a2)](https://github.com/sponsors/ix-infrastructure)
+
 An OpenCode plugin that brings [Ix Memory](https://github.com/ix-infrastructure/Ix)'s graph-first reasoning into OpenCode as a native cognitive layer.
 
 OpenCode + Ix = reasoning engine + persistent code knowledge graph. Skills are cognitive abstractions — not CLI wrappers — that start with cheap graph signals before reading source, and stop early when the question is answered.
diff --git a/install.ps1 b/install.ps1
index f10c3da..8ecfd3d 100644
--- a/install.ps1
+++ b/install.ps1
@@ -1,3 +1,5 @@
+# Copyright 2026 Ix Infrastructure Inc.
+
 # install.ps1 — ix-opencode-plugin installer for Windows
 #
 # Usage:
diff --git a/install.sh b/install.sh
index c5d0552..0c5ea2c 100755
--- a/install.sh
+++ b/install.sh
@@ -1,4 +1,6 @@
 #!/usr/bin/env bash
+# Copyright 2026 Ix Infrastructure Inc.
+
 # install.sh — ix-opencode-plugin installer
 #
 # Usage:
diff --git a/plugins/ix-plugin.ts b/plugins/ix-plugin.ts
index c13ee9c..ae9aa89 100644
--- a/plugins/ix-plugin.ts
+++ b/plugins/ix-plugin.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * ix-plugin.ts — OpenCode plugin entry point (v1.4.2 format)
  *
diff --git a/runtime/cli.ts b/runtime/cli.ts
index e35b9fa..e9d3d40 100644
--- a/runtime/cli.ts
+++ b/runtime/cli.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 import { $ } from "bun";
 
 /**
diff --git a/runtime/client.ts b/runtime/client.ts
index 6d6ae86..3d373de 100644
--- a/runtime/client.ts
+++ b/runtime/client.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * Ix Core Runtime HTTP client.
  *
diff --git a/runtime/llm.ts b/runtime/llm.ts
index c990fcb..043d320 100644
--- a/runtime/llm.ts
+++ b/runtime/llm.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * ix `--format llm` fast-path, gated on the installed CLI's version.
  *
diff --git a/runtime/secrets.ts b/runtime/secrets.ts
index 04d2f04..2337233 100644
--- a/runtime/secrets.ts
+++ b/runtime/secrets.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * Secret detection and redaction for Ix runtime payloads.
  *
diff --git a/tests/llm.test.ts b/tests/llm.test.ts
index 8246249..0f5997d 100644
--- a/tests/llm.test.ts
+++ b/tests/llm.test.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * The `--format llm` gate.
  *
diff --git a/tests/tools.test.ts b/tests/tools.test.ts
index 0679039..b945e21 100644
--- a/tests/tools.test.ts
+++ b/tests/tools.test.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * OpenCodeToolContractParity + RuntimeUnavailableFallback + BunCompatibility
  *
diff --git a/tools/ix-decide.ts b/tools/ix-decide.ts
index 01621d0..cde75c1 100644
--- a/tools/ix-decide.ts
+++ b/tools/ix-decide.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * ix-decide — pre-edit policy gate
  *
diff --git a/tools/ix-docs-tool.ts b/tools/ix-docs-tool.ts
index 2c8aaa9..c6313d6 100644
--- a/tools/ix-docs-tool.ts
+++ b/tools/ix-docs-tool.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * ix-docs-tool — doc/context summary retrieval
  *
diff --git a/tools/ix-explain.ts b/tools/ix-explain.ts
index 6fd5445..16feab5 100644
--- a/tools/ix-explain.ts
+++ b/tools/ix-explain.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * ix-explain — symbol deep explanation
  *
diff --git a/tools/ix-health.ts b/tools/ix-health.ts
index 4d09a3a..d3852db 100644
--- a/tools/ix-health.ts
+++ b/tools/ix-health.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * ix-health — CLI and graph availability probe
  *
diff --git a/tools/ix-history.ts b/tools/ix-history.ts
index 35e860d..00cae3a 100644
--- a/tools/ix-history.ts
+++ b/tools/ix-history.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * ix-history — revision and history lookup
  *
diff --git a/tools/ix-impact.ts b/tools/ix-impact.ts
index 0d0715c..23ad4d8 100644
--- a/tools/ix-impact.ts
+++ b/tools/ix-impact.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * ix-impact — blast radius analysis
  *
diff --git a/tools/ix-ingest.ts b/tools/ix-ingest.ts
index 4861a02..e903161 100644
--- a/tools/ix-ingest.ts
+++ b/tools/ix-ingest.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * ix-ingest — ingest status and trigger
  *
diff --git a/tools/ix-inventory.ts b/tools/ix-inventory.ts
index 18c473b..166b01b 100644
--- a/tools/ix-inventory.ts
+++ b/tools/ix-inventory.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * ix-inventory — enumerate files or symbols within a path scope
  *
diff --git a/tools/ix-locate.ts b/tools/ix-locate.ts
index 5a1fa93..ab71403 100644
--- a/tools/ix-locate.ts
+++ b/tools/ix-locate.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * ix-locate — text / semantic search
  *
diff --git a/tools/ix-map.ts b/tools/ix-map.ts
index d817333..b7a5517 100644
--- a/tools/ix-map.ts
+++ b/tools/ix-map.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * ix-map — architectural map and subsystem overview
  *
diff --git a/tools/ix-neighbors.ts b/tools/ix-neighbors.ts
index 74fc7ee..b6b2a51 100644
--- a/tools/ix-neighbors.ts
+++ b/tools/ix-neighbors.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * ix-neighbors — neighborhood traversal
  *
diff --git a/tools/ix-query.ts b/tools/ix-query.ts
index c1821e7..fa63be6 100644
--- a/tools/ix-query.ts
+++ b/tools/ix-query.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * ix-query — graph entity lookup
  *
diff --git a/tools/ix-rank.ts b/tools/ix-rank.ts
index 25d07a6..f58dbe4 100644
--- a/tools/ix-rank.ts
+++ b/tools/ix-rank.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * ix-rank — rank symbols by a graph metric
  *
diff --git a/tools/ix-smells.ts b/tools/ix-smells.ts
index d6d103b..9cfdcda 100644
--- a/tools/ix-smells.ts
+++ b/tools/ix-smells.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * ix-smells — architecture smell detection
  *
diff --git a/tools/ix-stats.ts b/tools/ix-stats.ts
index 9a67a39..49e1f8f 100644
--- a/tools/ix-stats.ts
+++ b/tools/ix-stats.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * ix-stats — graph-wide statistics
  *
diff --git a/tools/ix-subsystems.ts b/tools/ix-subsystems.ts
index bbe550a..7037df0 100644
--- a/tools/ix-subsystems.ts
+++ b/tools/ix-subsystems.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * ix-subsystems — list graph-derived subsystems
  *
diff --git a/tools/ix-trace.ts b/tools/ix-trace.ts
index 6212eab..a65769f 100644
--- a/tools/ix-trace.ts
+++ b/tools/ix-trace.ts
@@ -1,3 +1,5 @@
+// Copyright 2026 Ix Infrastructure Inc.
+
 /**
  * ix-trace — execution path tracing
  *