MOTIVATION

_links is a reserved top-level key in render payloads. The three view builders populate it with a map of { key: { href, label } }, and render::render_page emits a breadcrumb nav strip above the <h1> from that map, then filters it out of the body render so it doesn't appear twice.

Every entry across all three pages is either a site constant, a slug-derived URL, or a trivially-computable adjacent URL. None of it is data about the world, turn, or entity the page represents. It's navigation chrome — UI-only metadata — being carried through the JSON payload.

The operating principle going forward: the data model describes what exists; the UI layer decides how to present what exists. Nothing that only makes sense in the context of a rendered page belongs in the payload. _links fails that test and is removed.

This follows the same pattern and same spec shape as ticket 8d949ef3-6d47-47e8-bc8e-1356913b4639 (remove _embed). That ticket is prior art for this one; there is no parent edge.

A later ticket will reintroduce navigation properly: the renderer takes a NavContext carrying {page_type, world_slug, turn, entity_id, chain_range} and produces the breadcrumb strip from that context, not from the payload. That ticket is not filed yet and is not blocked by this one — rendering pages without a breadcrumb strip for the brief window between this ticket and the follow-up is the explicit temporary regression.

================================================================ WHAT _links DOES TODAY

Scope:

• Reserved top-level key in payloads. Shape: { "_links": { "key": { "href": "/some/url", "label": "text" }, ... } }.
• render_page reads it and calls render_links to emit a <nav class="links"> strip above the page title.
• The top-level object iteration in render_object_body skips the key at depth 2 so it doesn't render as body data.

Per page, the contents are:

• Session page: self → /w/:slug, dashboard → /dashboard
• Turn page: self → /w/:slug/turn/:n, session → /w/:slug, prev_turn → /w/:slug/turn/:n-1 (iff n > min), next_turn → /w/:slug/turn/:n+1 (iff n < max)
• Entity page: self → /w/:slug/entity/:id, session → /w/:slug

All derivable from the route, the slug, and the chain range. None are properties of the world, turn, or entity.

Who produces it today:

• views::build_session_payload — writes self + dashboard.
• views::build_turn_payload — writes self + session + prev_turn + next_turn.
• views::build_entity_payload — writes self + session.

Who consumes it downstream:

• render::render_page via render_links.
• Nothing else.

================================================================ THE RULE

After this ticket: _links does not exist as a concept in the render pipeline. No payload-level navigation map. The renderer has no reserved top-level keys; every top-level key in the payload renders as body data per the universal rules.

Temporary regression: pages render without a breadcrumb strip. Navigation between pages is possible by URL or via the /dashboard listing (which was already a working discovery surface and still is).

A later ticket will add NavContext-driven breadcrumb generation in the renderer — out of scope here.

================================================================ FILE-BY-FILE CHANGES

src/render.rs

Remove:

• The render_links function. Entire function body (lines roughly 117-140).
• The top-level _links extraction in render_page: the match block starting let links_html = match payload { ... } and the body.push_str(&links_html); that follows.
• The reserved-key filter in render_object_body for _links: the if depth == 2 && key == "_links" branch (roughly lines 168-174). After removal the function iterates every top-level key as data.
• The signature of wrap_document currently takes links_html as an underscore-prefixed unused parameter (_links_html). Remove that parameter too — simplify to (title, body).

Update doc comments:

• Module-level //! rules summary: remove rule 7 entirely ("One reserved top-level key ..."). Renumber if needed (there are no follow-on rules). The summary now explicitly says the renderer has no reserved top-level keys; every key is data.
• render_page's own doc comment: remove the mention of _links and breadcrumb strip.

Remove test:

• links_renders_as_breadcrumb_and_not_in_body

Keep:

• replace_exact_skipping_tags (retained last time; still unused, still reserved for the pattern-rules follow-up, still triggers the one expected dead_code warning).
• All other tests. None of them rely on _links.

src/views.rs

In each of build_session_payload, build_turn_payload, and build_entity_payload:

• Delete the let mut links = serde_json::Map::new(); block.
• Delete every links.insert(...) call.
• Delete the final out.insert("_links".into(), Value::Object(links)); line.

Update module-level //! comment: remove the mention of _links being woven in. The builders now produce pure payloads — data about the world/turn/entity, nothing else.

Remove the prev_turn/next_turn chain-range query in build_turn_payload: the let chain = call_tool(env, "list_turns"...).ok(); block and the chain_range computation it feeds. That call only existed to gate prev_turn / next_turn link emission. With no _links to produce, the second MCP call is dead weight. Deleting it also removes one unnecessary round-trip per turn-page request.

Update the affected tests — three builders, several assertions:

• build_session_payload_surfaces_world_fields (already renamed in 8d949ef3): remove the links assertions at the end. Keep every other assertion intact.
• build_turn_payload_has_events_and_state (already renamed in 8d949ef3): remove the links assertions. Keep the rest.
• build_entity_payload_includes_kind_and_agent_fields: remove the links assertions. Keep the kind/goal/memory coverage.
• Any other test in the module that reads payload["_links"] — strip those assertions, keep the rest.

src/server.rs

No source changes required in this ticket. The handlers already don't produce _links; they only pass the payload through. Once the follow-up NavContext ticket lands, server.rs will construct and pass the context. That is not this ticket.

src/lib.rs

No changes.

Other files

None.

================================================================ ACCEPTANCE

• cargo build clean (dev + release), one expected dead_code warning on replace_exact_skipping_tags (unchanged from the previous ticket).
• cargo test --lib green. The links_renders_as_breadcrumb_and_not_in_body test is gone; the three views tests have their _links assertions stripped but otherwise pass; everything else still passes.
• cargo test --test phase0 green.
• cargo test --test ant_scenario green.
• rg '_links' src/ returns zero matches in production code.
• rg 'render_links' src/ returns zero matches.
• rg 'chain_range' src/views.rs returns zero matches.
• Live smoke against the deployed ant-verify world:
  • GET /w/ant-verify returns 200 HTML, page renders without a breadcrumb strip at the top, body content (slug / name / scenario / entities / turns) fully visible.
  • GET /w/ant-verify/turn/2 returns 200 HTML, world state and events visible, no breadcrumb strip.
  • GET /w/ant-verify/entity/ant returns 200 HTML, entity state and timeline visible, no breadcrumb strip.
  • ?format=json on each of the three routes returns JSON that does NOT contain a _links key. Also does not contain _embed (removed previously).
  • All three 404 paths still return 404.
• No new Cargo dependencies.
• Commit message explicitly notes the temporary breadcrumb regression and names the follow-up that will reintroduce navigation via a NavContext.

================================================================ EXPLICITLY OUT OF SCOPE

• Adding any replacement navigation mechanism. That is the follow-up ticket (not yet filed). Do NOT add a NavContext, a nav helper, or any other breadcrumb-producing code in this ticket. Pure removal.
• Touching replace_exact_skipping_tags. Reserved for the pattern-rules ticket.
• View-builder refactor beyond removing the _links construction and the dead chain_range query. Do NOT collapse helpers, do NOT reorder payload keys, do NOT change what else gets inserted.
• Renderer refactor beyond removing _links. Do NOT change scalar / object / array rendering. Do NOT change heading depth rules or the prose threshold. Do NOT change CSS.
• MCP handler changes. None. _links never crossed that boundary.
• Adding the NavContext struct or doing any prep work for it. It lives in a separate ticket on its own clean slate.

================================================================ NO OPEN KNOBS

Same narrow discipline as the _embed removal. No judgment calls required from the handler. Any question that arises mid-implementation gets a comment on the ticket, not a guess.

Done per spec. Pure removal. Bundled with ticket 6438ac5b into a single deploy at the caller's explicit request.

Source changes

src/render.rs (−79 / +5):

• Deleted render_links fn.
• Dropped _links extraction in render_page (the match payload { ... } block) and the subsequent body.push_str(&links_html);.
• Dropped the _links reserved-key filter in render_object_body — the function now renders every top-level key as data with no special cases.
• Deleted test links_renders_as_breadcrumb_and_not_in_body.
• Module-level //! rules summary: removed rule 7 entirely. Summary now explicitly states the renderer has NO reserved top-level keys.
• render_page doc comment: dropped breadcrumb mention.
• Kept intact: replace_exact_skipping_tags (reserved for pattern-rules follow-up, produces one expected dead_code warning).
• wrap_document signature was already (title, body) from the prior ticket — no change this round.

src/views.rs (−131 / +5):

• Removed links Map + every links.insert + final out.insert("_links", ...) in all three builders.
• In build_turn_payload, also removed the secondary list_turns call and chain_range computation. That call only existed to gate prev/next_turn link emission; with no _links to emit, it was dead code and one extra MCP round-trip per turn-page request.
• Stripped _links assertions from three tests (build_session_payload_surfaces_world_fields, build_turn_payload_has_events_and_state, build_entity_payload_includes_kind_and_agent_fields) — kept every non-_links assertion.
• Module //! updated: builders produce pure payloads; no mention of _links being woven in.

src/server.rs / src/lib.rs / Cargo.toml / MCP handlers — unchanged.

Receipts

Commits on main, pushed to gitlab:

• 0dc77db refactor: remove _links from the render pipeline
• 763cb53 Merge branch 'feat/drop-links'
• bdded26 Merge branch 'feat/css-polish' (the parallel ticket's merge; included in the same push for context)

Tests (merged main):

• cargo build dev + release: clean (one expected dead_code warning on the retained replace_exact_skipping_tags).
• cargo test --lib: 303 passed (was 304; −1 net from the deleted links_renders_as_breadcrumb_and_not_in_body — CSS ticket added zero tests).
• cargo test --test phase0: 14 passed.
• cargo test --test ant_scenario: 4 passed including the live-router regression suite (~258s, on the feat/drop-links branch before merge).
• rg '_links' src/: only two coincidental substrings in unrelated test-function names (landing_links_to_http_manifest, caller_queue_banner_caps_at_five_links_and_shows_more). No production references.
• rg 'render_links' src/: no matches.
• rg 'chain_range' src/views.rs: no matches.

Deploy: bash k8s/deploy.sh clean; pod chukwa-59bdbdf6d7-6z6fp Running 1/1; watcher reconnected emitting orphans_killed 0 (new pod, no pre-existing shells) and backlog for all three live tickets.

Production smoke on live ant-verify world:

• GET /w/ant-verify → HTTP 200. JSON top-level keys: ['slug', 'name', 'scenario', 'current_turn', 'simulation_time', 'environment', 'entities', 'turns'] — NO _links, NO _embed. HTML body confirmed free of <nav class="links"> (grep count 0).
• GET /w/ant-verify/turn/1 → HTTP 200. Keys: ['slug', 'turn', 'turn_ref', 'state', 'events']. No _links.
• GET /w/ant-verify/entity/ant → HTTP 200. Keys: ['slug', 'id', 'name', 'kind', 'state', 'goal', 'memory', 'state_transitions', 'events']. No _links.
• All three 404 paths still 404.
• Pod log: no panics, no errors.

Expected and called-out temporary regression

HTML pages at /w/:slug/... now render with NO breadcrumb strip at the top. Navigation between pages happens via URL or via the /dashboard listing (which remains a working discovery surface). The follow-up NavContext ticket (not yet filed) will restore the breadcrumb strip constructed from {page_type, world_slug, turn, entity_id, chain_range} rather than from payload directives.

replace_exact_skipping_tags continues to carry the one expected dead_code warning — still reserved for the pattern-rules follow-up (also not yet filed).

Per standing guidance I am not confirming this ticket — only proposing. Over to you.