diff --git a/modules/gitea/client.ts b/modules/gitea/client.ts
index 33afefe5..6a2ba438 100644
--- a/modules/gitea/client.ts
+++ b/modules/gitea/client.ts
@@ -533,7 +533,7 @@ export class GiteaClient {
    *  **A listing the forge cut is no listing** (it says `truncated` on a page with nothing more to read, or the pages
    *  run past a bound): the call fails naming the repository and the commit, never answering the directories it did
    *  see, since a directory left out would be taken for one without a module. Reads only. */
-  async commitTrees(owner: string, repo: string, sha: string): Promise<{ root: string; trees: Record<string, string> }> {
+  async commitTrees(owner: string, repo: string, sha: string, paths?: Record<string, string[]>): Promise<{ root: string; trees: Record<string, string>; paths?: Record<string, Record<string, string>> }> {
     const base = `${repoPath(owner, repo)}/git/trees/${commitSegment(sha)}?recursive=true`;
     const cut = (why: string) => new Error(`the forge's tree listing of ${owner}/${repo} at ${sha} was cut (${why}); no trees are answered from a part`);
     const entries: any[] = [];
@@ -560,7 +560,22 @@ export class GiteaClient {
       if (!tree) throw new Error(`the forge's tree listing of ${owner}/${repo} at ${sha} holds ${e.path} but not the tree of ${dir}`);
       trees[dir] = tree;
     }
-    return { root, trees };
+    if (paths === undefined) return { root, trees };
+    // **Named paths** (novox/hq ADR 0499 §3, issue 1758): each asked path's git object id at the commit, a file's or a
+    // directory's, from the same listing, by directory and by path relative to it. A path the listing lacks fails
+    // naming both, and nothing is answered in part.
+    const objectOf = new Map<string, string>();
+    for (const e of entries) if (typeof e?.path === "string" && (e.type === "tree" || e.type === "blob")) objectOf.set(e.path, String(e.sha));
+    const named: Record<string, Record<string, string>> = {};
+    for (const [dir, list] of Object.entries(paths)) {
+      named[dir] = {};
+      for (const p of list) {
+        const id = objectOf.get(dir === "" ? p : `${dir}/${p}`);
+        if (!id) throw new Error(`the path ${p} of ${dir === "" ? "the repository root" : dir} is not in ${owner}/${repo} at ${sha}`);
+        named[dir][p] = id;
+      }
+    }
+    return { root, trees, paths: named };
   }
 
   /** Whether a repository holds a file at a commit: true, false for a 404, thrown when the forge cannot say. */
diff --git a/modules/gitea/test/commit-trees.test.ts b/modules/gitea/test/commit-trees.test.ts
index 51801d7d..e685a5c0 100644
--- a/modules/gitea/test/commit-trees.test.ts
+++ b/modules/gitea/test/commit-trees.test.ts
@@ -171,3 +171,53 @@ test("the root tree is git's hash of the root's own entries, never the listing's
     server.close();
   }
 });
+
+test("named paths: each asked path's git object id at the commit, a file's or a directory's, by directory (1758 S1, ADR 0499 §3)", async () => {
+  const { client, server } = await serve([{ sha: COMMIT, url: "u", tree: LISTING, truncated: false, page: 1, total_count: LISTING.length }]);
+  try {
+    const got = await client.commitTrees("novox", "hq", COMMIT, { "modules/a": ["main.go", "module.json"], "modules/b": ["c"], "": ["README.md", "modules/d"] });
+    assert.deepEqual(got.paths, {
+      "modules/a": { "main.go": h("6"), "module.json": h("5") },
+      "modules/b": { c: h("8") },
+      "": { "README.md": h("1"), "modules/d": h("a") },
+    });
+    assert.deepEqual(got.trees, { "": ROOT, "modules/a": h("4"), "modules/b/c": h("8") });
+    assert.equal((await client.commitTrees("novox", "hq", COMMIT)).paths, undefined, "no paths asked, none answered");
+  } finally {
+    server.close();
+  }
+});
+
+test("a named path the listing lacks fails naming the directory and the path, and answers nothing", async () => {
+  const { client, server } = await serve([{ sha: COMMIT, url: "u", tree: LISTING, truncated: false, page: 1, total_count: LISTING.length }]);
+  try {
+    await assert.rejects(client.commitTrees("novox", "hq", COMMIT, { "modules/a": ["main.go", "gone.go"] }), (err: Error) => {
+      assert.match(err.message, /modules\/a/);
+      assert.match(err.message, /gone\.go/);
+      return true;
+    });
+    for (const bad of [[""], ["../x"], ["/abs"], ["a//b"]]) {
+      await assert.rejects(client.commitTrees("novox", "hq", COMMIT, { "modules/a": bad }), /./, JSON.stringify(bad));
+    }
+  } finally {
+    server.close();
+  }
+});
+
+test("gitea_commit_trees takes paths as {directory: [paths]} and refuses another shape before the forge is asked", async () => {
+  const { getGiteaTools } = await import("../tools/index.ts");
+  const { client, server, asked } = await serve([{ sha: COMMIT, url: "u", tree: LISTING, truncated: false, page: 1, total_count: LISTING.length }]);
+  try {
+    const tool = getGiteaTools(client).find((t) => t.name === "gitea_commit_trees")!;
+    assert.ok("paths" in tool.input, "the tool names the argument");
+    const got: any = await tool.run({ owner: "novox", repo: "hq", sha: COMMIT, paths: { "modules/a": ["main.go"] } } as any);
+    assert.deepEqual(got.paths, { "modules/a": { "main.go": h("6") } });
+    const before = asked.length;
+    for (const paths of ["modules/a", ["main.go"], { "modules/a": "main.go" }, { "modules/a": [1] }]) {
+      await assert.rejects(tool.run({ owner: "novox", repo: "hq", sha: COMMIT, paths } as any), /paths/, JSON.stringify(paths));
+    }
+    assert.equal(asked.length, before, "the forge was asked for a refused call");
+  } finally {
+    server.close();
+  }
+});
diff --git a/modules/gitea/tools/index.ts b/modules/gitea/tools/index.ts
index d639a6b8..f5bbb0b1 100644
--- a/modules/gitea/tools/index.ts
+++ b/modules/gitea/tools/index.ts
@@ -60,6 +60,22 @@ function namesChecked(tools: ToolDefinition[]): ToolDefinition[] {
   }));
 }
 
+/** The `paths` argument of gitea_commit_trees: {directory: [path relative to it]}, each path plain (no empty, `.` or `..`
+ *  segment, not absolute); anything else is refused before the forge is asked. Absent is absent. */
+function namedPaths(raw: unknown): Record<string, string[]> | undefined {
+  if (raw === undefined || raw === null) return undefined;
+  if (typeof raw !== "object" || Array.isArray(raw)) throw new Error("paths is {directory: [path, ...]}");
+  const out: Record<string, string[]> = {};
+  for (const [dir, list] of Object.entries(raw as Record<string, unknown>)) {
+    if (!Array.isArray(list) || list.some((p) => typeof p !== "string")) throw new Error(`paths of ${dir || "the root"} is a list of paths`);
+    for (const p of list as string[]) {
+      if (p === "" || p.split("/").some((seg) => seg === "" || seg === "." || seg === "..")) throw new Error(`paths: ${JSON.stringify(p)} of ${dir || "the root"} is not a plain relative path`);
+    }
+    out[dir] = list as string[];
+  }
+  return out;
+}
+
 export function getGiteaTools(gitea: GiteaClient, admin?: () => GiteaAdmin): ToolDefinition[] {
   return namesChecked(allGiteaTools(gitea, admin));
 }
@@ -525,18 +541,19 @@ function allGiteaTools(gitea: GiteaClient, admin?: () => GiteaAdmin): ToolDefini
     },
     {
       name: "gitea_commit_trees",
-      description: "A commit's trees from the forge's one recursive listing: the root tree, and the tree of every directory that holds a module.json (the root as an empty name), each by its git hash. What the forge bridge puts in a merge's message (novox/hq ADR 0437 §5). The commit is a full 40-hex sha. A listing the forge cut is refused, never answered in part. Reads only.",
+      description: "A commit's trees from the forge's one recursive listing: the root tree, and the tree of every directory that holds a module.json (the root as an empty name), each by its git hash. What the forge bridge puts in a merge's message (novox/hq ADR 0437 §5). With paths, {directory: [path relative to it]}, the answer also carries paths, {directory: {path: git object id}} of each named file or directory at the commit (novox/hq ADR 0499 §3); a path the commit lacks fails naming the directory and the path. The commit is a full 40-hex sha. A listing the forge cut is refused, never answered in part. Reads only.",
       input: {
         owner: { type: "string", description: "the repository owner" },
         repo: { type: "string", description: "the repository name" },
         sha: { type: "string", description: "the commit, its full 40-hex sha" },
+        paths: { type: "object", description: "optional, {directory: [path relative to it]}: the git object id of each named file or directory is answered under paths; the root directory is the empty name" },
       },
       run: async (args) => {
         const owner = String(args.owner ?? "").trim(), repo = String(args.repo ?? "").trim();
         const sha = String(args.sha ?? "").trim();
         if (!owner || !repo) throw new Error("name the repository: owner and repo");
         if (!/^[0-9a-f]{40}$/i.test(sha)) throw new Error("sha is a commit's full 40-hex sha");
-        return gitea.commitTrees(owner, repo, sha);
+        return gitea.commitTrees(owner, repo, sha, namedPaths(args.paths));
       },
     },
     {