cutover endpoint

[insipx]

create an endpoint for the d14n cutover timestamp. closes #3031

[insipx]

This PR is part of a stack of 8 bookmarks:

1. trunk()
2. push-qqtpmktputny
3. push-rmpzuuomqxrs ← this PR
4. push-zwqsrxnyywwx
5. push-tlyurqorvnrq
6. push-wvmtovzklxpl
7. push-szzlusvwrmur
8. push-xutprvmtzsru
9. push-tlzvqnqvukmt

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Created with jj-stack

[claude]

Claude finished @insipx's task —— View job

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Code Review - PR #3118

Reviewed on: February 25, 2026 at 15:00 UTC

Todo List

• Read changed files to understand implementation
• Analyze code quality and potential issues
• Check test coverage
• Provide concise feedback

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Critical Issue

Type mismatch in Endpoint implementation (fetch_d14n_cutover.rs:11)

impl Endpoint for FetchD14nCutover {
    type Output = FetchD14nCutover;  // ❌ Should be FetchD14nCutoverResponse

This is a blocker. The Output type should be FetchD14nCutoverResponse, not FetchD14nCutover. This pattern is inconsistent with all other endpoints in the codebase (see GetInboxIds, HealthCheck, PublishClientEnvelopes, etc., which all use their respective response types). This will cause deserialization failures when the endpoint attempts to decode the gRPC response.

Fix:

type Output = FetchD14nCutoverResponse;

Minor Issues

1. Proto cache collision potential (proto_cache.rs:33-46): The current implementation inserts both input and output types into METHOD_LOOKUP, which could overwrite entries if type names collide within the same package. While this may be intentional, consider adding a comment explaining the precedence or checking for existing entries before inserting.

2. Test coverage: The actual integration test is marked #[ignore] (line 39), leaving only a path verification test. While understandable until the service is implemented, this contributes to the 59% patch coverage reported by codecov.

What's Good

• Clean, minimal implementation following existing patterns
• Proper use of pbjson_types::Empty for empty request body
• Test structure is in place for when service is ready
• Proto module generation looks correct

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[macroscopeapp]

Add xmtp_api_d14n::endpoints::d14n::FetchD14nCutover to call /xmtp.migration.api.v1.D14nMigrationApi/FetchD14nCutover with an empty body and index RPC methods by output types in xmtp_proto::proto_cache::METHOD_LOOKUP

Introduce the FetchD14nCutover endpoint with tests, export it via the d14n module, add generated xmtp.migration.api.v1 code, and update METHOD_LOOKUP to map by output types. See fetch_d14n_cutover.rs and proto_cache.rs.

📍Where to Start

Start with the endpoint definition and tests in fetch_d14n_cutover.rs, then review the method map changes in proto_cache.rs.

^{Macroscope summarized 5300943.}

[codecov]

Codecov Report

❌ Patch coverage is 59.25926% with 11 lines in your changes missing coverage. Please review.
✅ Project coverage is 73.77%. Comparing base (18b4334) to head (5300943).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
..._api_d14n/src/endpoints/d14n/fetch_d14n_cutover.rs	42.10%	11 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3118   +/-   ##
=======================================
  Coverage   73.76%   73.77%           
=======================================
  Files         450      451    +1     
  Lines       56355    56380   +25     
=======================================
+ Hits        41569    41592   +23     
- Misses      14786    14788    +2     

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[claude]

Claude Code is working…

I'll analyze this and get back to you.

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