feat(tracing): store spend in ClickHouse automatically

[yujonglee-berri]

TLDR

Problem this solves:

• Agent runs show tokens but no request costs
• Spend reads and inserts need the Rust storage boundary

How it solves it:

• Enabling ClickHouse tracing also stores proxy spend automatically
• Named Rust queries match costs by response ID and tenant
• Unknown ClickHouse insert fields now fail visibly
• Local script starts both databases and the Python proxy

Intentional product change: Agent Traces adds cost fields so operators can see matched request spend; unmatched costs show as unavailable

User Flow

Before: an operator sees agent spans but cannot see their LiteLLM request costs

1. The operator enables ClickHouse tracing and starts the proxy
2. Their agent sends a request through the proxy and exports spans to POST http://localhost:4000/v1/traces
3. They open http://localhost:4000/ui/?page=logs and select the run
4. The run shows tokens and spans, but no request cost

After: the same run shows costs for matching requests

1. The operator enables ClickHouse tracing and starts the proxy
2. Their agent sends a request through the proxy and exports spans to POST http://localhost:4000/v1/traces
3. They open http://localhost:4000/ui/?page=logs and select the run
4. The run shows request costs; a missing match remains unavailable

Pre-Submission checklist

• I have added meaningful tests
• The focused Python, Rust ClickHouse, and UI component tests pass locally
• My PR passes all required CI/CD checks
• My PR's scope is as isolated as possible
• I have received a Greptile Confidence Score of at least 4/5

Type

New Feature

Caveats (if any)

Medium

• Cost enrichment requires a matching response ID in the exported span

Low

• PR proof and UI screenshots remain pending at this tip

Final Attestation

• The tests cover successful writes, tenant isolation, duplicate IDs, and unavailable costs

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[devin-ai-integration]

Devin Review found 4 potential issues.

1 flag not posted on this PR by your GitHub settings — view it in Devin Review. (Configure)

[greptile-apps]

Confidence Score: 2/5

[High risk] Adds spend tracking to ClickHouse and wires it into the tracing system.

The PR is not ready to merge until unavailable pricing, oversized spend lookups, and spend-queue backpressure are addressed.

Findings

1.  Unknown cost appears free ▶
2.  Large pages lose costs ▶
3.  Spend queue can grow unbounded ▶
4.  Detail queries lack integration coverage ▶

Summary

This PR automatically records proxy spend when ClickHouse tracing is enabled, moves trace reads to named Rust queries, and displays matched costs in Agent Traces.

• Missing pricing can appear as zero cost, large trace pages can lose all cost enrichment, and sustained insert failures can grow the spend queue without bound.
• The new trace and span detail SQL lacks ClickHouse integration coverage.

_{Reviews (1) · Last reviewed commit: "feat(tracing): store spend in ClickHouse..."}

[codecov]

Codecov Report

❌ Patch coverage is 97.36842% with 3 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
litellm/tracing/store.py	92.85%	3 Missing ⚠️

📢 Thoughts on this report? Let us know!

[codspeed]

Merging this PR will not alter performance

✅ 31 untouched benchmarks

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_{Comparing litellm_trace_spend_enrichment_v2 (70b98f2) with main (6b9766f)¹}

Footnotes

1. No successful run was found on main (b41715b) during the generation of this report, so 6b9766f was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩