The fork tree of a repository is one JSON read and one MCP tool, in the same words as the /family page #12390

GET /api/v1/repos/:owner/:name/family now returns the fork tree as one JSON read. It is the same document the existing MCP fork_tree tool returns. Tests, the gate and tsc pass locally, apart from the full-suite run noted below.

What changed

• Route: src/http/api/family.ts calls forkTree, so the API and the tool share one code path. The answer is { root, nodes: [{ repo, parent, depth, follow, word }], truncated }.
• Visibility: only repositories the caller may read appear. A fork hidden from the caller is absent, and an unreadable repository answers 404.
• Caps: ?depth= takes 1–8 (default 4) and ?limit= takes 1–200 nodes. Anything else is a 422 with invalid_depth or invalid_limit. truncated: true says more exists than is shown.
• Registration: the route is wired into src/http/api.ts and listed in the OpenAPI routes (getApiV1ReposOwnerNameFamily.ts). One sentence is added to docs/REFERENCE.md.
• Tests: test/family-api.test.ts covers a private fork hidden from an outsider, the depth and limit caps with truncated, bad parameters, and the API and tool returning the same document for both an admin and an outsider.
• Checks: test/mcp-size.test.ts and the OpenAPI contract and drift tests pass. I did not run the whole suite, since the forge runs it on push.

What I did not do, and why

• No new MCP tool: fork_tree already existed and already returns this document, and family is taken by the forge-level tool behind /family. A second tool would only cost tools/list bytes.
• No docs/mcp/tools/ entry: that directory doesn't exist. Tool docs live in each tool's doc string and in the docs/MCP.md table, where fork_tree is already listed.
• No response cache: the read is one query per generation plus one for follow modes, and its result depends on who is asking. A short-lived cache would have to be keyed per caller and could show a stale visibility decision. Breadth is capped by limit.
• /family page unchanged: it shows the forge-level family (parent forge and child forges), not a repository's fork tree.

Try it: curl -H "authorization: Bearer $TOKEN" "$PREVIEW/api/v1/repos/<owner>/<name>/family?depth=1"

The fork tree of a repository is now one JSON read: GET /api/v1/repos/:owner/:name/family returns the same document the MCP fork_tree tool does. A fork the caller cannot see is absent from it, and the depth of the tree is capped.

The last push failed the gate because the header comment in test/family-api.test.ts was 122 columns wide. I rewrapped it to fit within 100 and changed nothing else.

bun scripts/gate.ts, bun x tsc --noEmit and test/family-api.test.ts (5 tests) all pass locally. I did not run the rest of the suite; the forge runs the full check on the push.

To try it, call the /family endpoint with a token on any repository that has forks, or call fork_tree over MCP.

GET /api/v1/repos/:owner/:name/family now returns the fork tree as JSON, the same document MCP fork_tree returns. This push fixes the failed check on that route; I have not seen the forge's re-run.

The route had two problems:

• Index not regenerated: src/contract/openapi/routes/index.ts was stale. I ran bun scripts/openapi-routes.ts to bring it current.
• Bounds not declared: the route's depth and limit query parameters had no bounds in the OpenAPI document, which test/openapi-limit-bounds.test.ts requires. They now state depth 1 to 8 and limit 1 to 200, matching what the handler enforces.

Check results:

• Local runs: openapi-routes, openapi-limit-bounds, forge-to-forge-walk and traffic-truth all pass, as do scripts/gate.ts and tsc.
• Not reproduced: the check's six reported failures were cut off in the log. I reproduced the OpenAPI ones and the traffic-truth one ("keeps prefixes and a sketch"), which passes here; the "connecting a fri…" test was truncated, and I took it to be one in forge-to-forge-walk. I did not run the full suite.

How to try it: curl $FORGE_URL/api/v1/repos/trevato/forge/family?depth=2&limit=10.

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