fix(pkg/da): fix json rpc types

[julienrbrt]

Overview

Tiny bug discovered because we've added RawHeader in #3146, does not warrant a changelog because not released.
Seeing this when on latest main.

2026-03-24T17:42:13.782Z	ERROR	rpc	go-jsonrpc@v0.10.1/client.go:506	error unmarshaling chan response: json: cannot unmarshal number into Go struct field RawHeader.header.height of type string
2026-03-24T17:42:13.824Z	ERROR	rpc	go-jsonrpc@v0.10.1/client.go:506	error unmarshaling chan response: json: cannot unmarshal number into Go struct field RawHeader.header.height of type string

https://github.com/celestiaorg/celestia-node/blob/8a784915e9fd92be22815e2aa8a50a060a7e94a2/header/header.go#L84-L86

Summary by CodeRabbit

• Bug Fixes
  • Corrected the data type handling for height values in JSON responses, ensuring proper numeric processing instead of text-based handling for improved data accuracy and consistency.

[github-actions]

The latest Buf updates on your PR. Results from workflow CI / buf-check (pull_request).

Build	Format	Lint	Breaking	Updated (UTC)
✅ passed	⏩ skipped	✅ passed	✅ passed	Mar 24, 2026, 6:45 PM

[coderabbitai]

📝 Walkthrough

Walkthrough

Two struct field types in the JSON RPC header module were updated from string to uint64: RawHeader.Height and Commit.Height. These changes align the JSON-decoded height fields with numeric types rather than strings, with no modifications to exported function signatures or control flow.

Changes

Cohort / File(s)	Summary
JSON RPC Header Types pkg/da/jsonrpc/header.go	Updated RawHeader.Height and Commit.Height field types from string to uint64 for numeric height representation in JSON decoding.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

Poem

🐰 Hop, hop, hooray! The heights now stand tall,
No more string-bound chains for numbers so small,
uint64 muscles flex with numeric might,
Our JSON dreams soar to numeric height! 📈✨

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 inconclusive)

Check name	Status	Explanation	Resolution
Description check	❓ Inconclusive	The PR description provides context about the bug, error messages, and references to related PRs, but lacks clear explanation of the fix applied.	Add an explicit explanation of what changes were made (updating Height fields from string to uint64) and why this fixes the unmarshaling error.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly describes the main change: fixing JSON-RPC types in the pkg/da package by converting height fields from string to uint64.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch julien/jsonrpc

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[claude]

Claude finished @julienrbrt's task in 54s —— View job

---

Code Review

• Gather context and read changed files
• Review the changes
• Post final review

---

LGTM. The fix is correct and minimal.

What changed

pkg/da/jsonrpc/header.go:23,29: RawHeader.Height and Commit.Height changed from string → uint64.

The celestia-node API encodes these nested height fields as plain JSON numbers (e.g. 123), not quoted strings ("123"). The old string type caused the unmarshaling failure reported in the PR description.

One observation worth noting

Header.Height (line 14) still uses json:"height,string,omitempty" — i.e. it expects a quoted number. This is intentional: the top-level height field on ExtendedHeader uses string encoding, while the nested header.height and commit.height fields use plain numeric encoding. The fix correctly matches the upstream celestia-node type:

// celestia-node: header.go#L84-L86// Height is encoded as a plain number in the nested header/commit,// but as a quoted string at the top-level ExtendedHeader.

Minor: no test coverage for Header deserialization

TestClient_CallsAreForwarded only exercises the blob API. There's no test that round-trips a Header through the JSON-RPC layer, which is why this regression wasn't caught earlier. Consider adding a test like:

funcTestHeader_UnmarshalJSON(t*testing.T) {
raw:=`{"header":{"chain_id":"test","height":42,"time":"..."},"commit":{"height":42},...}`varh jsonrpc.Headerrequire.NoError(t, json.Unmarshal([]byte(raw), &h))
require.Equal(t, uint64(42), h.Header.Height)
require.Equal(t, uint64(42), h.Commit.Height)
}

Not blocking — the fix itself is correct.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 61.12%. Comparing base (1b73b88) to head (605ee53).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@ Coverage Diff @@## main #3200 +/- ##
==========================================
+ Coverage 61.09% 61.12% +0.03% 
==========================================
Files 117 117 Lines 12082 12082 ==========================================
+ Hits 7381 7385 +4 + Misses 3873 3870 -3 + Partials 828 827 -1 

Flag	Coverage Δ
combined	61.12% <ø> (+0.03%)	⬆️

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