diff --git a/tests/auto_agents/controller/test_ci_summary_parsers.py b/tests/auto_agents/controller/test_ci_summary_parsers.py
new file mode 100644
index 000000000..63b99bfbf
--- /dev/null
+++ b/tests/auto_agents/controller/test_ci_summary_parsers.py
@@ -0,0 +1,299 @@
+"""Tests for the per-tool CI summary parsers (Phase 1j).
+
+Validates each parser:
+- Extracts findings from canonical CLI output
+- Populates summary_line, error_class, log_excerpt correctly
+- Handles empty/garbage input without raising
+"""
+from __future__ import annotations
+
+import pytest
+
+from tools.controller.ci_summary_parsers import (
+    EXPECTED_PARSERS,
+    NOX_SESSION_TO_PARSER,
+)
+from tools.controller.ci_summary_parsers import _stub, behave, pyright, ruff
+from tools.controller.ci_summary_parsers._base import select_log_excerpt
+from tools.controller.ci_summary_parsers._registry import (
+    resolve,
+    resolve_for_nox_session,
+    validate_parser_coverage,
+)
+
+
+# ─── shared base helpers ────────────────────────────────────────────
+
+
+class TestSelectLogExcerpt:
+    def test_empty_log(self):
+        excerpt, lines = select_log_excerpt("")
+        assert excerpt == ""
+        assert lines == 0
+
+    def test_short_log_returned_whole(self):
+        log = "line 1\nline 2\nline 3\n"
+        excerpt, lines = select_log_excerpt(log, tail_lines=80)
+        assert "line 1" in excerpt
+        assert lines == 3
+
+    def test_long_log_tail_kept(self):
+        log = "\n".join(f"line {i}" for i in range(200))
+        excerpt, lines = select_log_excerpt(log, tail_lines=10)
+        assert "line 199" in excerpt
+        assert "line 100" not in excerpt
+        assert lines == 10
+
+    def test_hard_char_cap_respected(self):
+        log = "x" * 50_000
+        excerpt, lines = select_log_excerpt(log, max_chars=1000)
+        assert len(excerpt) <= 1000
+
+
+# ─── ruff ───────────────────────────────────────────────────────────
+
+
+class TestRuffParser:
+    def test_lint_findings_parsed(self):
+        log = """\
+tools/x.py:10:5: F401 `os` imported but unused
+tools/y.py:20:1: E501 line too long (90 > 88 characters)
+Found 2 errors.
+"""
+        result = ruff.parse(log, "CI / lint")
+        assert len(result.findings) == 2
+        codes = [f.error_class for f in result.findings]
+        assert codes == ["F401", "E501"]
+        assert "Ruff found 2 error(s)" in result.summary_line
+        assert result.error_class == "RuffMixed"
+
+    def test_all_findings_same_class(self):
+        log = """\
+a.py:1:1: F401 unused
+b.py:2:1: F401 unused
+Found 2 errors.
+"""
+        result = ruff.parse(log, "lint")
+        assert result.error_class == "F401"
+
+    def test_format_findings_parsed(self):
+        log = """\
+Would reformat: tools/a.py
+Would reformat: tools/b.py
+2 files would be reformatted
+"""
+        result = ruff.parse(log, "format")
+        assert len(result.findings) == 2
+        assert all(f.error_class == "format" for f in result.findings)
+        assert "would be reformatted" in result.findings[0].summary
+
+    def test_empty_log(self):
+        result = ruff.parse("", "lint")
+        assert result.findings == []
+        assert result.error_class == "RuffEmpty"
+
+    def test_garbage_log_no_crash(self):
+        result = ruff.parse("totally not ruff output\nnope nope\n", "lint")
+        assert result.findings == []
+        # Falls back to "0 ruff findings" summary
+        assert "0" in result.summary_line or "ruff" in result.summary_line.lower()
+
+    def test_locations_populated(self):
+        log = "tools/x.py:42:10: F401 foo\n"
+        result = ruff.parse(log, "lint")
+        assert len(result.failing_locations) == 1
+        assert result.failing_locations[0].file_path == "tools/x.py"
+        assert result.failing_locations[0].line_range == "42-42"
+
+
+# ─── pyright ───────────────────────────────────────────────────────
+
+
+class TestPyrightParser:
+    def test_basic_diagnostic(self):
+        log = """\
+/home/runner/work/repo/tools/foo.py:10:5 - error: Cannot find name 'x' (reportUnknownVariableType)
+/home/runner/work/repo/tools/bar.py:1:1 - warning: trivial (reportUnusedImport)
+1 errors, 1 warnings, 0 informations
+"""
+        result = pyright.parse(log, "typecheck")
+        assert len(result.findings) == 2
+        errs = [f for f in result.findings if f.severity == "error"]
+        assert len(errs) == 1
+        assert errs[0].error_class == "reportUnknownVariableType"
+        assert "Pyright: 1 errors" in result.summary_line
+
+    def test_path_normalization(self):
+        log = "/abs/path/work/tools/foo.py:10:5 - error: msg (reportFoo)\n"
+        result = pyright.parse(log, "typecheck")
+        assert result.findings[0].location.file_path == "tools/foo.py"
+
+    def test_no_errors_only_warnings(self):
+        log = """\
+/x/tools/foo.py:1:1 - warning: trivial (reportUnusedImport)
+0 errors, 1 warnings, 0 informations
+"""
+        result = pyright.parse(log, "typecheck")
+        # Errors-only locations → empty
+        assert result.failing_locations == []
+        assert result.error_class == "PyrightClean"
+
+    def test_empty_log(self):
+        result = pyright.parse("", "typecheck")
+        assert result.findings == []
+        assert result.error_class == "PyrightClean"
+
+    def test_two_errors_diff_classes(self):
+        log = """\
+/x/tools/a.py:1:1 - error: a (reportFoo)
+/x/tools/b.py:2:2 - error: b (reportBar)
+2 errors, 0 warnings, 0 informations
+"""
+        result = pyright.parse(log, "typecheck")
+        assert result.error_class == "PyrightMixed"
+
+    def test_two_errors_same_class(self):
+        log = """\
+/x/tools/a.py:1:1 - error: a (reportFoo)
+/x/tools/b.py:2:2 - error: b (reportFoo)
+2 errors, 0 warnings, 0 informations
+"""
+        result = pyright.parse(log, "typecheck")
+        assert result.error_class == "reportFoo"
+
+
+# ─── behave ────────────────────────────────────────────────────────
+
+
+class TestBehaveParser:
+    def test_failing_scenario_extracted(self):
+        log = """\
+Feature: My feature
+  Scenario: My scenario
+    Then baz failed
+
+Failing scenarios:
+  tests/features/foo.feature:10  Scenario: My scenario
+
+0 features passed, 1 failed, 0 skipped
+0 scenarios passed, 1 failed, 0 skipped
+2 steps passed, 1 failed, 1 skipped
+    AssertionError: expected 1 == 2
+"""
+        result = behave.parse(log, "unit_tests")
+        assert len(result.findings) == 1
+        assert result.findings[0].error_class == "ScenarioFailed"
+        assert "My scenario" in result.findings[0].summary
+        loc = result.findings[0].location
+        assert loc.file_path == "tests/features/foo.feature"
+        assert loc.line_range == "10-10"
+        assert "Behave: 1 feature(s) failed" in result.summary_line
+
+    def test_no_failing_scenarios(self):
+        log = """\
+1 features passed, 0 failed, 0 skipped
+1 scenarios passed, 0 failed, 0 skipped
+"""
+        result = behave.parse(log, "unit_tests")
+        assert result.findings == []
+        assert result.error_class == "BehaveClean"
+
+    def test_empty_log(self):
+        result = behave.parse("", "unit_tests")
+        assert result.findings == []
+
+    def test_assertion_extracted(self):
+        log = """\
+Failing scenarios:
+  tests/x.feature:5  Scenario: foo
+
+AssertionError: my-message-here
+0 features passed, 1 failed, 0 skipped
+0 scenarios passed, 1 failed, 0 skipped
+"""
+        result = behave.parse(log, "unit_tests")
+        assert len(result.failed_assertions) == 1
+        assert "my-message-here" in result.failed_assertions[0].assertion_excerpt
+
+
+# ─── stub ──────────────────────────────────────────────────────────
+
+
+class TestStubParser:
+    def test_stub_returns_pending_marker(self):
+        log = "any log content\nmore\n"
+        parse = _stub.make_stub("robot_framework")
+        result = parse(log, "integration_tests")
+        assert result.error_class == "parser-pending-robot_framework"
+        assert "parser pending" in result.summary_line
+        assert "any log content" in result.log_excerpt
+        assert len(result.findings) == 1
+        assert result.findings[0].severity == "error"
+
+    def test_each_stub_independently_named(self):
+        a = _stub.make_stub("bandit")
+        b = _stub.make_stub("vulture")
+        ra = a("log", "g")
+        rb = b("log", "g")
+        assert ra.error_class != rb.error_class
+
+
+# ─── registry ──────────────────────────────────────────────────────
+
+
+class TestRegistry:
+    def test_resolve_real_ruff(self):
+        r = resolve("ruff")
+        assert r.is_stub is False
+        assert r.name == "ruff"
+        assert r.version == "v1"
+
+    def test_resolve_real_pyright(self):
+        r = resolve("pyright")
+        assert r.is_stub is False
+        assert r.parse is pyright.parse
+
+    def test_resolve_real_behave(self):
+        r = resolve("behave")
+        assert r.is_stub is False
+
+    def test_resolve_pending_stub(self):
+        r = resolve("robot_framework")
+        assert r.is_stub is True
+        assert r.version == "v1-stub"
+
+    def test_resolve_for_nox_session_single(self):
+        parsers = resolve_for_nox_session("lint")
+        assert [p.name for p in parsers] == ["ruff"]
+
+    def test_resolve_for_nox_session_composite(self):
+        parsers = resolve_for_nox_session("security_scan")
+        names = [p.name for p in parsers]
+        assert names == ["bandit", "semgrep", "vulture"]
+
+    def test_resolve_for_unknown_session_raises(self):
+        with pytest.raises(KeyError):
+            resolve_for_nox_session("nope_not_a_session")
+
+    def test_validate_parser_coverage(self):
+        cov = validate_parser_coverage()
+        # Every name in EXPECTED_PARSERS shows up.
+        assert set(cov.keys()) == EXPECTED_PARSERS
+        # ruff/pyright/behave are real; rest are stubs.
+        assert cov["ruff"] is True
+        assert cov["pyright"] is True
+        assert cov["behave"] is True
+        assert cov["robot_framework"] is False
+        assert cov["bandit"] is False
+
+
+# ─── expected coverage shape ───────────────────────────────────────
+
+
+class TestExpectedCoverageShape:
+    def test_nox_session_map_only_references_known_parsers(self):
+        for parser in EXPECTED_PARSERS:
+            assert resolve(parser).name == parser
+
+    def test_security_scan_is_composite(self):
+        assert NOX_SESSION_TO_PARSER["security_scan"].startswith("multi:")
diff --git a/tests/auto_agents/controller/test_master_ci_summarize.py b/tests/auto_agents/controller/test_master_ci_summarize.py
new file mode 100644
index 000000000..b9c07e558
--- /dev/null
+++ b/tests/auto_agents/controller/test_master_ci_summarize.py
@@ -0,0 +1,231 @@
+"""Tests for the deterministic CI summarizer (Phase 1j).
+
+Validates summarize_ci_status orchestration:
+- Forgejo combined-status → CISummary dict shape (parses as
+  CISummary V1 contract).
+- Gate→nox-session resolution honors workflow naming convention.
+- Composite gates (security_scan) get composite_findings rows.
+- Failed log fetches degrade to log-fetch-failed CIFailure rather than
+  raising.
+- Unknown gate contexts fall through to NoParserAvailable cleanly.
+"""
+from __future__ import annotations
+
+from datetime import datetime, timezone
+
+import pytest
+
+from tools.controller.contracts.v1 import CISummary
+from tools.controller.master import summarize_ci_status
+
+
+# ─── fixtures ───────────────────────────────────────────────────────
+
+
+def _forgejo_status(statuses, *, overall="failure") -> dict:
+    return {"state": overall, "statuses": statuses}
+
+
+def _gate(*, context: str, state: str, target_url: str | None = None) -> dict:
+    return {"context": context, "state": state, "target_url": target_url}
+
+
+# ─── happy path ────────────────────────────────────────────────────
+
+
+class TestHappyPath:
+    def test_basic_summary(self):
+        statuses = [
+            _gate(context="CI / lint", state="success"),
+            _gate(context="CI / typecheck", state="success"),
+        ]
+        log_fetcher = lambda _: ""
+        summary = summarize_ci_status(
+            head_sha="abc", forgejo_status=_forgejo_status(statuses, overall="success"),
+            log_fetcher=log_fetcher,
+        )
+        assert summary["overall_state"] == "success"
+        assert summary["gates_total"] == 2
+        assert summary["gates_passed"] == 2
+        assert summary["gates_failed"] == 0
+        # No failures → no parser invocations.
+        for g in summary["gates"]:
+            assert g["failure"] is None
+
+    def test_failing_lint_invokes_ruff(self):
+        statuses = [_gate(context="CI / lint", state="failure")]
+        log = "tools/x.py:1:1: F401 unused\nFound 1 errors.\n"
+        summary = summarize_ci_status(
+            head_sha="abc",
+            forgejo_status=_forgejo_status(statuses),
+            log_fetcher=lambda _: log,
+        )
+        assert summary["gates_failed"] == 1
+        failure = summary["gates"][0]["failure"]
+        assert failure is not None
+        assert failure["parser_used"] == "ruff"
+        assert failure["error_class"] == "F401"
+        assert len(failure["findings"]) == 1
+
+    def test_parses_as_v1_contract(self):
+        statuses = [_gate(context="CI / lint", state="failure")]
+        summary = summarize_ci_status(
+            head_sha="abc",
+            forgejo_status=_forgejo_status(statuses),
+            log_fetcher=lambda _: "tools/x.py:1:1: F401 unused\nFound 1 errors.\n",
+        )
+        # The CISummary contract must accept the assembled dict.
+        parsed = CISummary.model_validate(summary)
+        assert parsed.gates_failed == 1
+        assert parsed.gates[0].failure.parser_used == "ruff"
+
+    def test_observed_at_default_now(self):
+        before = datetime.now(timezone.utc)
+        summary = summarize_ci_status(
+            head_sha="abc", forgejo_status=_forgejo_status([], overall="success"),
+            log_fetcher=lambda _: "",
+        )
+        after = datetime.now(timezone.utc)
+        assert before <= summary["observed_at"] <= after
+
+
+# ─── composite gates ───────────────────────────────────────────────
+
+
+class TestCompositeGates:
+    def test_security_scan_composite_findings(self):
+        statuses = [_gate(context="CI / security_scan", state="failure")]
+        summary = summarize_ci_status(
+            head_sha="abc",
+            forgejo_status=_forgejo_status(statuses),
+            log_fetcher=lambda _: "fake security log\n",
+        )
+        failure = summary["gates"][0]["failure"]
+        # bandit is the head parser (first in multi:); semgrep + vulture
+        # nest as composite_findings.
+        assert failure["parser_used"] == "bandit"
+        assert len(failure["composite_findings"]) == 2
+        names = [c["parser_used"] for c in failure["composite_findings"]]
+        assert names == ["semgrep", "vulture"]
+
+
+# ─── error handling ────────────────────────────────────────────────
+
+
+class TestErrorHandling:
+    def test_log_fetch_returns_none(self):
+        statuses = [_gate(context="CI / lint", state="failure")]
+        summary = summarize_ci_status(
+            head_sha="abc",
+            forgejo_status=_forgejo_status(statuses),
+            log_fetcher=lambda _: None,
+        )
+        failure = summary["gates"][0]["failure"]
+        assert failure["error_class"] == "log-fetch-failed"
+        assert failure["raw_log_excerpt"] == ""
+
+    def test_log_fetch_raises_handled(self):
+        statuses = [_gate(context="CI / lint", state="failure")]
+
+        def boom(_):
+            raise RuntimeError("network down")
+
+        summary = summarize_ci_status(
+            head_sha="abc",
+            forgejo_status=_forgejo_status(statuses),
+            log_fetcher=boom,
+        )
+        # Failure recorded but loop didn't crash.
+        assert summary["gates"][0]["failure"]["error_class"] == "log-fetch-failed"
+
+    def test_unknown_gate_no_parser(self):
+        statuses = [_gate(context="CI / mystery_gate", state="failure")]
+        summary = summarize_ci_status(
+            head_sha="abc",
+            forgejo_status=_forgejo_status(statuses),
+            log_fetcher=lambda _: "log content",
+        )
+        failure = summary["gates"][0]["failure"]
+        assert failure["error_class"] == "NoParserAvailable"
+
+    def test_forgejo_status_none(self):
+        summary = summarize_ci_status(
+            head_sha="abc", forgejo_status=None,
+            log_fetcher=lambda _: pytest.fail("should not be called"),
+        )
+        assert summary["overall_state"] == "unknown"
+        assert summary["gates"] == []
+
+    def test_parameterized_gate_name_normalized(self):
+        """Forgejo can emit "unit_tests-3.13" for matrix jobs."""
+        statuses = [_gate(context="CI / unit_tests-3.13", state="failure")]
+        summary = summarize_ci_status(
+            head_sha="abc",
+            forgejo_status=_forgejo_status(statuses),
+            log_fetcher=lambda _: "Failing scenarios:\n  x.feature:5  Scenario: bar\n0 features passed, 1 failed, 0 skipped\n0 scenarios passed, 1 failed, 0 skipped\n",
+        )
+        failure = summary["gates"][0]["failure"]
+        assert failure["parser_used"] == "behave"
+
+    def test_skip_coverage_session_no_parser(self):
+        # benchmark is in NOX_SESSIONS_SKIP_COVERAGE; should not parse.
+        statuses = [_gate(context="CI / benchmark", state="failure")]
+        summary = summarize_ci_status(
+            head_sha="abc",
+            forgejo_status=_forgejo_status(statuses),
+            log_fetcher=lambda _: pytest.fail("should not fetch log"),
+        )
+        # benchmark isn't in NOX_SESSION_TO_PARSER, so gate→session
+        # returns None → NoParserAvailable.
+        failure = summary["gates"][0]["failure"]
+        assert failure["error_class"] == "NoParserAvailable"
+
+
+# ─── parser_versions aggregate ─────────────────────────────────────
+
+
+class TestParserVersions:
+    def test_versions_collected_per_parser(self):
+        statuses = [
+            _gate(context="CI / lint", state="failure"),
+            _gate(context="CI / typecheck", state="failure"),
+        ]
+        summary = summarize_ci_status(
+            head_sha="abc",
+            forgejo_status=_forgejo_status(statuses),
+            log_fetcher=lambda _: "Found 0 errors.\n",
+        )
+        # Both ruff + pyright versions appear.
+        assert "ruff" in summary["parser_versions"]
+        assert "pyright" in summary["parser_versions"]
+        assert summary["parser_versions"]["ruff"] == "v1"
+
+    def test_stub_version_recorded(self):
+        statuses = [_gate(context="CI / complexity", state="failure")]
+        summary = summarize_ci_status(
+            head_sha="abc",
+            forgejo_status=_forgejo_status(statuses),
+            log_fetcher=lambda _: "radon log",
+        )
+        # complexity → radon (currently a stub).
+        assert summary["parser_versions"].get("radon") == "v1-stub"
+
+
+# ─── gate count aggregates ─────────────────────────────────────────
+
+
+class TestGateCounts:
+    def test_mixed_statuses(self):
+        statuses = [
+            _gate(context="CI / lint", state="success"),
+            _gate(context="CI / typecheck", state="failure"),
+            _gate(context="CI / unit_tests", state="pending"),
+            _gate(context="CI / build", state="error"),
+        ]
+        summary = summarize_ci_status(
+            head_sha="abc", forgejo_status=_forgejo_status(statuses),
+            log_fetcher=lambda _: "",
+        )
+        assert summary["gates_passed"] == 1
+        assert summary["gates_failed"] == 2  # failure + error
+        assert summary["gates_pending"] == 1
diff --git a/tools/controller/ci_summary_parsers/_base.py b/tools/controller/ci_summary_parsers/_base.py
new file mode 100644
index 000000000..ce4724c4a
--- /dev/null
+++ b/tools/controller/ci_summary_parsers/_base.py
@@ -0,0 +1,76 @@
+"""Shared types + helpers for per-CI-tool parsers.
+
+Every parser module exposes:
+- ``PARSER_VERSION: str`` — bumped when output semantics change.
+- ``parse(log: str, gate_name: str) -> ParserResult``
+
+Parsers are deterministic Python — no LLM. They take the gate's raw
+log text + the gate name, and return structured findings that fit the
+V1 ``CIFailure`` contract. Composite gates (e.g., nox security_scan =
+bandit + semgrep + vulture) get parsed by an orchestrator that calls
+each sub-parser and wraps the results in ``CIFailure.composite_findings``.
+"""
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+
+from ..contracts.v1 import CIFailureFinding, FailedAssertion, FileLocation
+
+
+# Default log-excerpt budget (V1 CIFailure.raw_log_excerpt max_length).
+DEFAULT_LOG_EXCERPT_CHARS = 16_384
+
+
+@dataclass(frozen=True)
+class ParserResult:
+    """One parser's structured output for one gate's log.
+
+    ``log_excerpt`` is the parser's selection of the most-relevant
+    log lines (smart-around-first-error, or trailing N lines). It MUST
+    fit within ``DEFAULT_LOG_EXCERPT_CHARS`` — the V1 contract enforces
+    this as max_length on the CIFailure field.
+
+    ``log_excerpt_lines`` is the count of newline-separated lines in
+    the excerpt, used by the contract field of the same name.
+    """
+
+    error_class: str
+    summary_line: str
+    findings: list[CIFailureFinding] = field(default_factory=list)
+    failing_locations: list[FileLocation] = field(default_factory=list)
+    failed_assertions: list[FailedAssertion] = field(default_factory=list)
+    log_excerpt: str = ""
+    log_excerpt_lines: int = 0
+
+
+def select_log_excerpt(log: str, *, max_chars: int = DEFAULT_LOG_EXCERPT_CHARS,
+                       tail_lines: int = 80) -> tuple[str, int]:
+    """Pick the most-relevant excerpt from a log.
+
+    Strategy: prefer the LAST ``tail_lines`` (most test/build tools
+    emit failure context at the end). If the tail exceeds ``max_chars``,
+    truncate from the head of the tail (keep the bottom).
+
+    Returns ``(excerpt, line_count)``. An empty log produces ``("", 0)``.
+    """
+    if not log:
+        return "", 0
+    lines = log.splitlines()
+    if len(lines) <= tail_lines:
+        excerpt = log
+    else:
+        excerpt = "\n".join(lines[-tail_lines:])
+    if len(excerpt) > max_chars:
+        excerpt = excerpt[-max_chars:]
+        # Trim a partial leading line to keep it clean.
+        nl = excerpt.find("\n")
+        if 0 < nl < 200:
+            excerpt = excerpt[nl + 1:]
+    return excerpt, excerpt.count("\n") + (1 if excerpt and not excerpt.endswith("\n") else 0)
+
+
+__all__ = [
+    "DEFAULT_LOG_EXCERPT_CHARS",
+    "ParserResult",
+    "select_log_excerpt",
+]
diff --git a/tools/controller/ci_summary_parsers/_registry.py b/tools/controller/ci_summary_parsers/_registry.py
new file mode 100644
index 000000000..c7503fe82
--- /dev/null
+++ b/tools/controller/ci_summary_parsers/_registry.py
@@ -0,0 +1,88 @@
+"""Parser registry — resolve a parser name to a (parser_version,
+parse_function) pair.
+
+Real parsers ship their own module under ``ci_summary_parsers/``. For
+the not-yet-shipped tools, the registry returns a stub from
+``_stub.make_stub(name)``. The startup coverage validator
+``validate_parser_coverage()`` flags any name in EXPECTED_PARSERS
+that still resolves to a stub so the operator can prioritize.
+"""
+from __future__ import annotations
+
+import importlib
+import logging
+from collections.abc import Callable
+from dataclasses import dataclass
+
+from . import EXPECTED_PARSERS, NOX_SESSION_TO_PARSER
+from . import _stub
+from ._base import ParserResult
+
+logger = logging.getLogger(__name__)
+
+
+# Parsers that ship in Phase 1j (real implementations).
+_REAL_PARSERS: frozenset[str] = frozenset({"ruff", "pyright", "behave"})
+
+
+@dataclass(frozen=True)
+class ResolvedParser:
+    name: str
+    version: str
+    parse: Callable[[str, str], ParserResult]
+    is_stub: bool
+
+
+def resolve(parser_name: str) -> ResolvedParser:
+    """Look up the parser for ``parser_name``. Returns a stub if the
+    real module isn't shipped yet (logs at WARNING level so operators
+    notice the parser gap)."""
+    if parser_name in _REAL_PARSERS:
+        try:
+            mod = importlib.import_module(
+                f"tools.controller.ci_summary_parsers.{parser_name}",
+            )
+            return ResolvedParser(
+                name=parser_name,
+                version=getattr(mod, "PARSER_VERSION", "v1"),
+                parse=mod.parse,
+                is_stub=False,
+            )
+        except ImportError:
+            logger.warning(
+                "real parser %s declared but import failed; using stub",
+                parser_name,
+            )
+    return ResolvedParser(
+        name=parser_name,
+        version=_stub.PARSER_VERSION,
+        parse=_stub.make_stub(parser_name),
+        is_stub=True,
+    )
+
+
+def resolve_for_nox_session(nox_session: str) -> list[ResolvedParser]:
+    """Map nox session → ordered list of parsers (most sessions have
+    one; composite security_scan has three).
+
+    Raises KeyError if the session has no mapping (forces operator to
+    update NOX_SESSION_TO_PARSER explicitly)."""
+    entry = NOX_SESSION_TO_PARSER[nox_session]  # KeyError is intentional
+    if entry.startswith("multi:"):
+        names = entry.split(":", 1)[1].split(",")
+        return [resolve(n.strip()) for n in names if n.strip()]
+    return [resolve(entry)]
+
+
+def validate_parser_coverage() -> dict[str, bool]:
+    """Return a {parser_name: is_real} map for every parser in
+    EXPECTED_PARSERS. Operators can plot this to see parser gaps."""
+    return {p: not resolve(p).is_stub for p in sorted(EXPECTED_PARSERS)}
+
+
+__all__ = [
+    "ResolvedParser",
+    "resolve",
+    "resolve_for_nox_session",
+    "validate_parser_coverage",
+]
diff --git a/tools/controller/ci_summary_parsers/_stub.py b/tools/controller/ci_summary_parsers/_stub.py
new file mode 100644
index 000000000..1ca350fa5
--- /dev/null
+++ b/tools/controller/ci_summary_parsers/_stub.py
@@ -0,0 +1,55 @@
+"""Stub parser for tools whose deterministic parser isn't shipped yet.
+
+Returns a structured CIFailure-shape result that carries the raw log
+excerpt + a ``parser-pending`` marker. The implementer's prompt can
+still surface the failing log; the operator-side coverage dashboard
+flags these as parser gaps to prioritize.
+
+Phase 1j ships ruff/pyright/behave; Phase 1j+ ships the rest. Until
+then, these tools use this stub:
+- robot_framework  (integration_tests, e2e_tests)
+- slipcover        (coverage_report)
+- bandit, semgrep, vulture (security_scan composite)
+- radon            (complexity)
+- build            (build)
+"""
+from __future__ import annotations
+
+from ..contracts.v1 import CIFailureFinding
+from ._base import ParserResult, select_log_excerpt
+
+PARSER_VERSION = "v1-stub"
+
+
+def make_stub(parser_name: str):
+    """Factory: returns a ``parse(log, gate_name)`` for the given
+    parser name. Each stub identifies itself in ``error_class``."""
+
+    def parse(log: str, gate_name: str) -> ParserResult:
+        excerpt, lines = select_log_excerpt(log)
+        finding = CIFailureFinding(
+            error_class=f"parser-pending-{parser_name}",
+            summary=(
+                f"Structured parser for '{parser_name}' is not yet "
+                f"implemented; falling back to raw log excerpt."
+            )[:512],
+            location=None,
+            severity="error",
+        )
+        return ParserResult(
+            error_class=f"parser-pending-{parser_name}",
+            summary_line=(
+                f"{parser_name}: parser pending; see raw_log_excerpt"
+            )[:200],
+            findings=[finding],
+            failing_locations=[],
+            failed_assertions=[],
+            log_excerpt=excerpt,
+            log_excerpt_lines=lines,
+        )
+
+    parse.__name__ = f"parse_stub_{parser_name}"
+    return parse
+
+
+__all__ = ["PARSER_VERSION", "make_stub"]
diff --git a/tools/controller/ci_summary_parsers/behave.py b/tools/controller/ci_summary_parsers/behave.py
new file mode 100644
index 000000000..9a26bbcc6
--- /dev/null
+++ b/tools/controller/ci_summary_parsers/behave.py
@@ -0,0 +1,143 @@
+"""Behave parser — handles ``nox -s unit_tests``.
+
+Behave's CLI emits a tree-style trace per scenario:
+
+    Feature: My feature  # tests/features/foo.feature:3
+      Scenario: My scenario  # tests/features/foo.feature:10
+        Given foo                                                       # passed
+        When bar                                                        # passed
+        Then baz                                                        # failed: AssertionError: expected 1 == 2
+          File "tests/steps/baz_steps.py", line 10, in step_then
+            assert 1 == 2, "expected 1 == 2"
+        AssertionError: expected 1 == 2
+
+    Failing scenarios:
+      tests/features/foo.feature:10  Scenario: My scenario
+
+    0 features passed, 1 failed, 0 skipped
+    0 scenarios passed, 1 failed, 0 skipped
+    2 steps passed, 1 failed, 1 skipped
+
+The parser extracts each failing scenario as a ``FailedAssertion``
++ a ``CIFailureFinding`` so the implementer can navigate to the
+right feature file + step file.
+"""
+from __future__ import annotations
+
+import re
+
+from ..contracts.v1 import CIFailureFinding, FailedAssertion, FileLocation
+from ._base import ParserResult, select_log_excerpt
+
+PARSER_VERSION = "v1"
+
+# "  tests/features/foo.feature:10  Scenario: My scenario"
+_FAILING_SCENARIO_RE = re.compile(
+    r"^\s+(?P<feature>\S+\.feature):(?P<line>\d+)\s+Scenario:\s+(?P<name>.+?)\s*$",
+    re.MULTILINE,
+)
+# "1 feature passed, 0 failed, 0 skipped"
+_FEATURE_SUMMARY_RE = re.compile(
+    r"(\d+)\s+features?\s+passed,\s+(\d+)\s+failed,\s+(\d+)\s+skipped",
+)
+_SCENARIO_SUMMARY_RE = re.compile(
+    r"(\d+)\s+scenarios?\s+passed,\s+(\d+)\s+failed,\s+(\d+)\s+skipped",
+)
+# AssertionError line OR Exception line.
+_ASSERT_RE = re.compile(
+    r"^\s*(?P<exc>AssertionError|Exception|.+Error):\s*(?P<msg>.+?)\s*$",
+    re.MULTILINE,
+)
+
+
+def parse(log: str, gate_name: str) -> ParserResult:
+    findings: list[CIFailureFinding] = []
+    locations: list[FileLocation] = []
+    assertions: list[FailedAssertion] = []
+
+    failing_scenarios = list(_FAILING_SCENARIO_RE.finditer(log))
+
+    # Map scenario → an excerpt of the surrounding log so we can lift
+    # the assertion line for the FailedAssertion.
+    for m in failing_scenarios:
+        loc = FileLocation(
+            file_path=m["feature"],
+            line_range=f"{m['line']}-{m['line']}",
+            function_or_test=m["name"][:120],
+        )
+        findings.append(CIFailureFinding(
+            error_class="ScenarioFailed",
+            summary=f"Scenario failed: {m['name'][:200]}"[:512],
+            location=loc,
+            severity="error",
+        ))
+        locations.append(loc)
+
+    # Pull the first matching assertion globally — multi-assertion
+    # extraction would over-fit on rare logs. The raw excerpt carries
+    # the rest of the context.
+    for am in _ASSERT_RE.finditer(log):
+        exc = am["exc"].strip()
+        if exc.endswith("Error"):
+            msg = am["msg"].strip()[:512]
+            # Best-effort context: 10 lines around the match.
+            excerpt = _excerpt_around(log, am.start(), 10)
+            assertions.append(FailedAssertion(
+                test_name=(failing_scenarios[0]["name"][:120]
+                           if failing_scenarios else "(unknown)"),
+                expected=None,
+                actual=None,
+                assertion_excerpt=(f"{exc}: {msg}\n\n{excerpt}")[:4096],
+            ))
+            break
+
+    summary_line = _summary_line(log, n_failing=len(failing_scenarios))
+    excerpt, lines = select_log_excerpt(log)
+    error_class = "BehaveFailure" if findings else "BehaveClean"
+
+    return ParserResult(
+        error_class=error_class,
+        summary_line=summary_line,
+        findings=findings,
+        failing_locations=locations,
+        failed_assertions=assertions,
+        log_excerpt=excerpt,
+        log_excerpt_lines=lines,
+    )
+
+
+def _summary_line(log: str, *, n_failing: int) -> str:
+    feat = _FEATURE_SUMMARY_RE.search(log)
+    sce = _SCENARIO_SUMMARY_RE.search(log)
+    if feat and sce:
+        return (
+            f"Behave: {feat.group(2)} feature(s) failed, "
+            f"{sce.group(2)} scenario(s) failed"
+        )[:200]
+    if n_failing:
+        return f"Behave: {n_failing} scenario(s) failed"[:200]
+    return "Behave: no failing scenarios parsed"
+
+
+def _excerpt_around(log: str, offset: int, lines_each_side: int) -> str:
+    # Walk N newlines back, N newlines forward.
+    before = log.rfind("\n", 0, offset)
+    for _ in range(lines_each_side):
+        if before <= 0:
+            before = 0
+            break
+        before = log.rfind("\n", 0, before)
+        if before == -1:
+            before = 0
+            break
+    after = offset
+    for _ in range(lines_each_side):
+        nxt = log.find("\n", after + 1)
+        if nxt == -1:
+            after = len(log)
+            break
+        after = nxt
+    return log[before:after].strip("\n")[:2048]
+
+
+__all__ = ["PARSER_VERSION", "parse"]
diff --git a/tools/controller/ci_summary_parsers/pyright.py b/tools/controller/ci_summary_parsers/pyright.py
new file mode 100644
index 000000000..03fb1d701
--- /dev/null
+++ b/tools/controller/ci_summary_parsers/pyright.py
@@ -0,0 +1,117 @@
+"""Pyright parser — handles ``nox -s typecheck``.
+
+Pyright's CLI emits one diagnostic per line:
+
+    /abs/path/to/file.py:LINE:COL - error: human description (ruleName)
+    /abs/path/to/file.py:LINE:COL - warning: ...
+    1 error, 0 warnings, 0 informations
+
+Some Pyright versions use absolute paths; we normalize to the
+project-relative tail when a known segment (``tools/``, ``tests/``,
+``src/``) is in the path. Otherwise the absolute path is kept.
+"""
+from __future__ import annotations
+
+import re
+
+from ..contracts.v1 import CIFailureFinding, FileLocation
+from ._base import ParserResult, select_log_excerpt
+
+PARSER_VERSION = "v1"
+
+_DIAG_RE = re.compile(
+    r"^(?P<file>\S+?):(?P<line>\d+):(?P<col>\d+)\s+-\s+"
+    r"(?P<severity>error|warning|information)\s*:\s+"
+    r"(?P<message>.+?)\s*$",
+    re.MULTILINE,
+)
+# Some Pyright versions emit findings on TWO lines (path/loc then
+# indented message); we don't try to parse those (rare). The summary
+# line is canonical:
+_SUMMARY_RE = re.compile(
+    r"(\d+)\s+errors?,\s+(\d+)\s+warnings?,\s+(\d+)\s+informations?",
+)
+
+_PATH_NORMALIZE_SEGMENTS = ("/tools/", "/tests/", "/src/", "/.opencode/")
+
+
+def parse(log: str, gate_name: str) -> ParserResult:
+    findings: list[CIFailureFinding] = []
+    locations: list[FileLocation] = []
+
+    for m in _DIAG_RE.finditer(log):
+        sev_raw = m["severity"]
+        if sev_raw == "error":
+            severity = "error"
+            error_class = _extract_rule_name(m["message"]) or "PyrightError"
+        elif sev_raw == "warning":
+            severity = "warning"
+            error_class = _extract_rule_name(m["message"]) or "PyrightWarning"
+        else:
+            severity = "info"
+            error_class = "PyrightInfo"
+        loc = FileLocation(
+            file_path=_normalize_path(m["file"]),
+            line_range=f"{m['line']}-{m['line']}",
+        )
+        findings.append(CIFailureFinding(
+            error_class=error_class,
+            summary=m["message"].strip()[:512],
+            location=loc,
+            severity=severity,
+        ))
+        if severity == "error":
+            locations.append(loc)
+
+    summary_line = _summary_line(log, n_findings=len(findings))
+    excerpt, lines = select_log_excerpt(log)
+    error_class = _aggregate_error_class(findings)
+
+    return ParserResult(
+        error_class=error_class,
+        summary_line=summary_line,
+        findings=findings,
+        failing_locations=locations,
+        failed_assertions=[],
+        log_excerpt=excerpt,
+        log_excerpt_lines=lines,
+    )
+
+
+def _extract_rule_name(message: str) -> str | None:
+    """Pyright wraps the rule name in trailing parens. Pull it out."""
+    m = re.search(r"\((report[A-Za-z0-9]+)\)\s*$", message)
+    return m.group(1) if m else None
+
+
+def _normalize_path(path: str) -> str:
+    """Strip leading container path so the implementer can match the
+    workspace tree."""
+    for seg in _PATH_NORMALIZE_SEGMENTS:
+        idx = path.find(seg)
+        if idx >= 0:
+            return path[idx + 1:]
+    return path
+
+
+def _summary_line(log: str, *, n_findings: int) -> str:
+    m = _SUMMARY_RE.search(log)
+    if m:
+        return (
+            f"Pyright: {m.group(1)} errors, {m.group(2)} warnings, "
+            f"{m.group(3)} informations"
+        )[:200]
+    return f"Pyright: {n_findings} diagnostic(s) parsed"[:200]
+
+
+def _aggregate_error_class(findings: list[CIFailureFinding]) -> str:
+    errors = [f for f in findings if f.severity == "error"]
+    if not errors:
+        return "PyrightClean"
+    classes = {f.error_class for f in errors}
+    if len(classes) == 1:
+        return next(iter(classes))
+    return "PyrightMixed"
+
+
+__all__ = ["PARSER_VERSION", "parse"]
diff --git a/tools/controller/ci_summary_parsers/ruff.py b/tools/controller/ci_summary_parsers/ruff.py
new file mode 100644
index 000000000..44b61fc88
--- /dev/null
+++ b/tools/controller/ci_summary_parsers/ruff.py
@@ -0,0 +1,109 @@
+"""Ruff parser — handles ``nox -s lint`` and ``nox -s format``.
+
+Ruff's CLI prints one finding per line in the format:
+
+    path/to/file.py:LINE:COL: RULECODE  human description
+
+Followed by a trailing ``Found N errors.`` summary line. Format mode
+(`ruff format --check`) emits a different shape:
+
+    Would reformat: path/to/file.py
+    1 file would be reformatted
+
+Both shapes are absorbed below. Findings are emitted as
+``CIFailureFinding`` rows so the implementer's prompt can render
+"rule + file:line" with one entry per failure.
+"""
+from __future__ import annotations
+
+import re
+
+from ..contracts.v1 import CIFailureFinding, FileLocation
+from ._base import ParserResult, select_log_excerpt
+
+PARSER_VERSION = "v1"
+
+# Examples:
+#   tools/controller/master/loop.py:42:5: F401 `os` imported but unused
+#   tests/x.py:1:1: E501 line too long (90 > 88 characters)
+_LINT_RE = re.compile(
+    r"^(?P<file>[^\s:][^:]*):(?P<line>\d+):(?P<col>\d+):\s+"
+    r"(?P<code>[A-Z]+\d+)\s+(?P<message>.+)$",
+    re.MULTILINE,
+)
+# Examples: ``Would reformat: tools/foo.py``
+_FORMAT_RE = re.compile(r"^Would reformat:\s+(?P<file>\S+)\s*$", re.MULTILINE)
+# Summary lines we extract for summary_line in priority order.
+_SUMMARY_PATTERNS = [
+    re.compile(r"^Found (\d+) errors?\.?$", re.MULTILINE),
+    re.compile(r"^(\d+) files? would be reformatted$", re.MULTILINE),
+]
+
+
+def parse(log: str, gate_name: str) -> ParserResult:
+    findings: list[CIFailureFinding] = []
+    locations: list[FileLocation] = []
+
+    for m in _LINT_RE.finditer(log):
+        loc = FileLocation(
+            file_path=m["file"],
+            line_range=f"{m['line']}-{m['line']}",
+        )
+        findings.append(CIFailureFinding(
+            error_class=m["code"],
+            summary=m["message"].strip()[:512],
+            location=loc,
+            severity="error",
+        ))
+        locations.append(loc)
+
+    for m in _FORMAT_RE.finditer(log):
+        loc = FileLocation(file_path=m["file"])
+        findings.append(CIFailureFinding(
+            error_class="format",
+            summary="file would be reformatted",
+            location=loc,
+            severity="warning",
+        ))
+        locations.append(loc)
+
+    summary_line = _pick_summary(log, fallback=f"{len(findings)} ruff findings")
+    excerpt, lines = select_log_excerpt(log)
+    error_class = _aggregate_error_class(findings)
+
+    return ParserResult(
+        error_class=error_class,
+        summary_line=summary_line[:200],
+        findings=findings,
+        failing_locations=locations,
+        failed_assertions=[],
+        log_excerpt=excerpt,
+        log_excerpt_lines=lines,
+    )
+
+
+def _pick_summary(log: str, *, fallback: str) -> str:
+    for pat in _SUMMARY_PATTERNS:
+        matches = pat.findall(log)
+        if matches:
+            # Re-render: the regex captured the count.
+            n = matches[-1]
+            if pat is _SUMMARY_PATTERNS[0]:
+                return f"Ruff found {n} error(s)"
+            return f"Ruff: {n} file(s) need reformat"
+    return fallback
+
+
+def _aggregate_error_class(findings: list[CIFailureFinding]) -> str:
+    """If all findings share one error_class, surface it. Else use a
+    composite marker so the implementer's prompt shows a sensible
+    top-level error_class on the CIFailure."""
+    if not findings:
+        return "RuffEmpty"
+    classes = {f.error_class for f in findings}
+    if len(classes) == 1:
+        return next(iter(classes))
+    return "RuffMixed"
+
+
+__all__ = ["PARSER_VERSION", "parse"]
diff --git a/tools/controller/master/__init__.py b/tools/controller/master/__init__.py
index 2fdc3c3fe..5ae2c1b4b 100644
--- a/tools/controller/master/__init__.py
+++ b/tools/controller/master/__init__.py
@@ -71,6 +71,10 @@ from .backfill import (
     has_backfill_run,
     run_startup_backfill,
 )
+from .ci_summarize import (
+    LogFetcher,
+    summarize_ci_status,
+)
 from .prefetch import (
     GetPRDetailsCallback,
     GetPRDiffCallback,
@@ -166,4 +170,7 @@ __all__ = [
     "build_implementer_input",
     "build_reviewer_input",
     "make_prefetch_callback",
+    # CI summarizer (Phase 1j)
+    "LogFetcher",
+    "summarize_ci_status",
 ]
diff --git a/tools/controller/master/ci_summarize.py b/tools/controller/master/ci_summarize.py
new file mode 100644
index 000000000..24d45dcb9
--- /dev/null
+++ b/tools/controller/master/ci_summarize.py
@@ -0,0 +1,314 @@
+"""Deterministic CI summarizer — builds CISummary from Forgejo status.
+
+The implementer/reviewer prompt prefetch needs a CISummary V1 dict for
+the head_sha. This module takes the Forgejo combined-status response
+(``{"state": "...", "statuses": [...]}``) plus a log fetcher, and
+returns a fully-populated CISummary covering every gate.
+
+Per-gate flow:
+1. Map the Forgejo gate context (e.g., "CI / lint") → nox session
+   name. The job names in ``.forgejo/workflows/*.yml`` ARE the nox
+   session names by convention, so a simple suffix-after-/ extraction
+   works. Unknown contexts pass through as ``UnknownGate`` and skip
+   the parser.
+2. Look up the nox session in NOX_SESSION_TO_PARSER → one or more
+   parser names.
+3. For each parser, fetch the log (via the injected ``log_fetcher``),
+   run ``parse(log, gate_name)``, and wrap the result in a
+   GateResult.failure CIFailure dict.
+4. For composite gates (security_scan = bandit + semgrep + vulture),
+   the outer CIFailure carries the FIRST parser's structure + each
+   sub-parser's result goes into ``composite_findings``.
+
+The summarizer never raises — log fetch failures degrade to a
+``CIFailure`` with ``error_class='log-fetch-failed'`` so the
+implementer at least sees the failure existed.
+"""
+from __future__ import annotations
+
+import logging
+from collections.abc import Callable
+from datetime import datetime, timezone
+from typing import Any
+
+from ..ci_summary_parsers import NOX_SESSION_TO_PARSER, NOX_SESSIONS_SKIP_COVERAGE
+from ..ci_summary_parsers._registry import (
+    ResolvedParser,
+    resolve_for_nox_session,
+)
+
+logger = logging.getLogger(__name__)
+
+
+# log_fetcher(gate_name) -> str | None; production wires this to a
+# Forgejo job-log fetcher. None means the log was unreachable.
+LogFetcher = Callable[[str], str | None]
+
+
+# Forgejo status state → CISummary GateResult.status mapping.
+_FORGEJO_STATE_TO_GATE_STATUS = {
+    "success": "passed",
+    "failure": "failed",
+    "error": "error",
+    "pending": "pending",
+    "warning": "passed",  # advisory: treat as passed
+    None: "pending",
+}
+
+
+def summarize_ci_status(
+    *, head_sha: str, forgejo_status: dict | None, log_fetcher: LogFetcher,
+    observed_at: datetime | None = None,
+) -> dict:
+    """Build a CISummary-shape dict from the Forgejo combined-status.
+
+    Args:
+        head_sha: the commit SHA the status covers.
+        forgejo_status: response body from
+            ``GET /repos/{owner}/{repo}/commits/{sha}/status``.
+            Shape: ``{"state": str, "statuses": [{"context": str,
+            "state": str, "target_url": str}]}``. None for
+            "couldn't fetch" — produces a unknown-state summary.
+        log_fetcher: callable that takes the gate context and returns
+            the raw log text (or None if unreachable). Production
+            wires this via Forgejo's job-log endpoint.
+        observed_at: timestamp the status was fetched. Defaults to
+            now(UTC).
+
+    Returns the CISummary V1-shape dict (a CISummary contract parses
+    it after the caller validates).
+    """
+    when = observed_at or datetime.now(timezone.utc)
+    if forgejo_status is None:
+        return _unknown_summary(head_sha=head_sha, observed_at=when)
+
+    overall = _FORGEJO_OVERALL_STATE_MAPPING.get(
+        forgejo_status.get("state"), "unknown",
+    )
+    raw_statuses = forgejo_status.get("statuses") or []
+    statuses = [s for s in raw_statuses if isinstance(s, dict)]
+
+    gates: list[dict] = []
+    parser_versions: dict[str, str] = {}
+    for s in statuses:
+        gate, versions_seen = _build_gate(s, log_fetcher)
+        gates.append(gate)
+        parser_versions.update(versions_seen)
+
+    counts = _count_gates(gates)
+    return {
+        "summary_version": "V1",
+        "head_sha": head_sha,
+        "observed_at": when,
+        "overall_state": overall,
+        "gates": gates,
+        "gates_total": counts["total"],
+        "gates_passed": counts["passed"],
+        "gates_failed": counts["failed"],
+        "gates_skipped": counts["skipped"],
+        "gates_pending": counts["pending"],
+        "parser_versions": parser_versions,
+    }
+
+
+# Forgejo combined-status states → CISummary.overall_state.
+_FORGEJO_OVERALL_STATE_MAPPING: dict[str | None, str] = {
+    "success": "success",
+    "failure": "failure",
+    "error": "error",
+    "pending": "pending",
+    None: "unknown",
+}
+
+
+def _unknown_summary(*, head_sha: str, observed_at: datetime) -> dict:
+    return {
+        "summary_version": "V1",
+        "head_sha": head_sha,
+        "observed_at": observed_at,
+        "overall_state": "unknown",
+        "gates": [],
+        "gates_total": 0,
+        "gates_passed": 0,
+        "gates_failed": 0,
+        "gates_skipped": 0,
+        "gates_pending": 0,
+        "parser_versions": {},
+    }
+
+
+def _build_gate(
+    status: dict, log_fetcher: LogFetcher,
+) -> tuple[dict, dict[str, str]]:
+    """Build one GateResult dict + return parser versions used."""
+    context = status.get("context") or "(unknown)"
+    state_raw = status.get("state")
+    gate_status = _FORGEJO_STATE_TO_GATE_STATUS.get(state_raw, "pending")
+    target_url = status.get("target_url")
+    severity = "info" if gate_status in {"passed", "skipped"} else "error"
+
+    gate: dict[str, Any] = {
+        "name": context,
+        "status": gate_status,
+        "severity": severity,
+        "target_url": target_url,
+        "duration_seconds": None,
+        "failure": None,
+    }
+    parser_versions: dict[str, str] = {}
+
+    # Only parse failures/errors. Passed/pending/skipped don't need a
+    # log fetch — they have nothing to report.
+    if gate_status not in {"failed", "error"}:
+        return gate, parser_versions
+
+    nox_session = _gate_to_nox_session(context)
+    if nox_session is None or nox_session in NOX_SESSIONS_SKIP_COVERAGE:
+        gate["failure"] = _no_parser_failure(context)
+        return gate, parser_versions
+
+    try:
+        parsers = resolve_for_nox_session(nox_session)
+    except KeyError:
+        logger.warning(
+            "no parser map for nox session %r (gate=%r)",
+            nox_session, context,
+        )
+        gate["failure"] = _no_parser_failure(context)
+        return gate, parser_versions
+
+    log = _safe_fetch(log_fetcher, context)
+    if log is None:
+        gate["failure"] = _log_fetch_failed_failure(parsers, context)
+        for p in parsers:
+            parser_versions[p.name] = p.version
+        return gate, parser_versions
+
+    gate["failure"] = _build_failure(parsers, log, context, parser_versions)
+    return gate, parser_versions
+
+
+def _gate_to_nox_session(context: str) -> str | None:
+    """Forgejo gate context → nox session name.
+
+    Convention: ``<workflow-name> / <job-name>`` (e.g., "CI / lint").
+    The job name IS the nox session name by repo convention. If the
+    name doesn't match any known session, return None and let the
+    summarizer fall through to NoParserAvailable."""
+    if not context:
+        return None
+    tail = context.rsplit("/", 1)[-1].strip()
+    if tail in NOX_SESSION_TO_PARSER:
+        return tail
+    # Also support the parameterized form e.g. "unit_tests-3.13".
+    base = tail.split("-", 1)[0]
+    if base in NOX_SESSION_TO_PARSER:
+        return base
+    return None
+
+
+def _safe_fetch(log_fetcher: LogFetcher, context: str) -> str | None:
+    try:
+        return log_fetcher(context)
+    except Exception as exc:  # noqa: BLE001
+        logger.warning("log fetch raised for %s: %s", context, exc)
+        return None
+
+
+def _no_parser_failure(context: str) -> dict:
+    return {
+        "parser_used": "(none)",
+        "parser_version": "n/a",
+        "error_class": "NoParserAvailable",
+        "summary_line": f"No parser available for {context!r}"[:200],
+        "findings": [],
+        "failing_locations": [],
+        "failed_assertions": [],
+        "raw_log_excerpt": "",
+        "log_excerpt_lines": 0,
+        "composite_findings": [],
+    }
+
+
+def _log_fetch_failed_failure(parsers, context: str) -> dict:
+    parser_names = ", ".join(p.name for p in parsers)
+    return {
+        "parser_used": parser_names or "(unknown)",
+        "parser_version": "n/a",
+        "error_class": "log-fetch-failed",
+        "summary_line": f"Log fetch failed for {context!r}"[:200],
+        "findings": [],
+        "failing_locations": [],
+        "failed_assertions": [],
+        "raw_log_excerpt": "",
+        "log_excerpt_lines": 0,
+        "composite_findings": [],
+    }
+
+
+def _build_failure(
+    parsers: list[ResolvedParser], log: str, context: str,
+    parser_versions: dict[str, str],
+) -> dict:
+    """Build the CIFailure dict from one or more parsers' results.
+
+    For a single-parser gate the result becomes the outer CIFailure.
+    For a composite gate (multi: prefix), the FIRST parser becomes
+    the outer + the rest go into composite_findings.
+    """
+    results = []
+    for p in parsers:
+        try:
+            res = p.parse(log, context)
+            parser_versions[p.name] = p.version
+            results.append((p, res))
+        except Exception as exc:  # noqa: BLE001
+            logger.warning(
+                "parser %s raised on gate %r: %s", p.name, context, exc,
+            )
+            # Fall through with no result for this parser.
+
+    if not results:
+        return _log_fetch_failed_failure(parsers, context)
+
+    head_parser, head_result = results[0]
+    failure = _result_to_failure(head_parser, head_result)
+    if len(results) > 1:
+        failure["composite_findings"] = [
+            _result_to_failure(p, r) for p, r in results[1:]
+        ]
+    return failure
+
+
+def _result_to_failure(parser: ResolvedParser, result) -> dict:
+    return {
+        "parser_used": parser.name,
+        "parser_version": parser.version,
+        "error_class": result.error_class,
+        "summary_line": result.summary_line,
+        "findings": [f.model_dump() for f in result.findings],
+        "failing_locations": [loc.model_dump() for loc in result.failing_locations],
+        "failed_assertions": [a.model_dump() for a in result.failed_assertions],
+        "raw_log_excerpt": result.log_excerpt,
+        "log_excerpt_lines": result.log_excerpt_lines,
+        "composite_findings": [],
+    }
+
+
+def _count_gates(gates: list[dict]) -> dict[str, int]:
+    counts = {"total": len(gates), "passed": 0, "failed": 0,
+              "skipped": 0, "pending": 0}
+    for g in gates:
+        status = g.get("status")
+        if status == "passed":
+            counts["passed"] += 1
+        elif status in {"failed", "error"}:
+            counts["failed"] += 1
+        elif status == "skipped":
+            counts["skipped"] += 1
+        elif status == "pending":
+            counts["pending"] += 1
+    return counts
+
+
+__all__ = ["LogFetcher", "summarize_ci_status"]