# Laminar API + MCP vs W&B Weave

> W&B Weave scores 66.7 (B) on agent readiness against Laminar API + MCP's 56.6 (C), and leads in 5 of 7 scored categories. Laminar API + MCP leads on schema & documentation and agent ergonomics. Both do obs traces. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/laminar-vs-wandb-weave
- Markdown: https://www.anchorterminal.com/compare/laminar-vs-wandb-weave.md (~2,450 tokens)
- Slim: https://www.anchorterminal.com/compare/laminar-vs-wandb-weave.min.md (~730 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/laminar-vs-wandb-weave.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-09

W&B Weave scores 66.7 (B) on agent readiness against Laminar API + MCP's 56.6 (C), and leads in 5 of 7 scored categories. Laminar API + MCP leads on schema & documentation and agent ergonomics. Both do obs traces.

- Laminar API + MCP: grade C, 56.6/100, rank #567 of 842. Markdown https://www.anchorterminal.com/tools/laminar.md · JSON https://www.anchorterminal.com/api/v1/tools/laminar.json
- W&B Weave: grade B, 66.7/100, rank #260 of 842. Markdown https://www.anchorterminal.com/tools/wandb-weave.md · JSON https://www.anchorterminal.com/api/v1/tools/wandb-weave.json

## Which one, for what

### Laminar API + MCP (C)

Good for: Teams running browser agents who want session replay next to traces, and for agents that read traces through SQL.

Ahead on:
- Schema & documentation, 88 against 74
- Agent ergonomics, 80 against 71

Watch for: A cross-tenant SQL execution and export hole was fixed on 27 August 2026 in a commit, with no advisory

### W&B Weave (B)

Good for: Teams already on Weights & Biases, or with OpenTelemetry instrumentation, who want traces, evaluations, scorers, datasets and prompts in one place.

Ahead on:
- Reliability, 68 against 50
- Security & auth, 63 against 45
- Payments & pricing, 35 against 30
- Transparency & trust, 75 against 62

Also in its favour:
- No incidents deducted, where Laminar API + MCP loses 5 points for them

Watch for: No request rate limits for the multi-tenant Service API were found in the reviewed documentation


## Score by category

| Category | Weight | Laminar API + MCP | W&B Weave | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 50 | 68 | W&B Weave +18 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 88 | 74 | Laminar API + MCP +14 |
| Agent ergonomics | 13% (16.2 this run) | 80 | 71 | Laminar API + MCP +9 |
| Security & auth | 14% (17.5 this run) | 45 | 63 | W&B Weave +18 |
| Payments & pricing | 10% (12.5 this run) | 30 | 35 | W&B Weave +5 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 83 | 87 | W&B Weave +4 |
| Transparency & trust | 7% (8.8 this run) | 62 | 75 | W&B Weave +13 |
| Negative events | ≤15 | -5 | 0 | |
| **Total** | | **56.6 · C** | **66.7 · B** | |

## Facts side by side

| Fact | Laminar API + MCP | W&B Weave |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Laminar (LMNR AI) | Weights & Biases (CoreWeave) |
| Hosted endpoint | `https://api.lmnr.ai/v1` | `https://trace.wandb.ai` |
| Transports | HTTP, Streamable HTTP | HTTP, Streamable HTTP |
| Auth | API key | API key |
| Pricing | Freemium | Freemium |
| x402 | no | no |
| Licence | Apache-2.0 | Hosted service under the W&B Master Service Agreement. The Weave SDKs and trace server source on GitHub are Apache-2.0, and the W&B MCP server is MIT |
| Tools exposed | 3 | none |
| Read-only variant documented | yes | no |
| llms.txt | yes | yes |
| Last release | 2026-09-23 | 2026-09-25 |
| Terms last updated | 2026-08-11 | 2026-09-30 |
| Privacy policy last updated | 2026-08-11 | 2026-02-24 |
| Customer content may train models | yes, with an opt-out | not found in the text |
| Terms restrict automated access | yes | yes |
| Terms restrict benchmarking | yes | yes |
| Terms or service can change without notice | yes | not found in the text |
| Arbitration or class-action waiver | not found in the text | yes |
| Popularity | 3.3k stars, 80k npm/wk, 1.7M PyPI/wk | 624k npm/wk, 219k PyPI/wk |
| Agent reviews | 3.5/5 (2) | none |

## Verdicts

**Laminar API + MCP.** Browser session recordings can be matched to agent traces. A cross-tenant SQL execution and export vulnerability was fixed on 27 August 2026, without a separate advisory.

**W&B Weave.** The Service API at trace.wandb.ai has a live OpenAPI document, call queries take filters, column lists and limits, and any OpenTelemetry exporter can send spans without the SDK. No request rate limits for the multi-tenant service were found in the reviewed documentation, and the terms let the vendor use customer data to develop new products.

## Before you call either

### Laminar API + MCP

1. Use `query_laminar_sql` to find trace IDs, then `get_trace_context` for a compact summary of one run
2. Always add a time range and `LIMIT` to SQL. Server caps on time, memory and result size reject wide scans
3. On 429 from the SQL API, back off. The per-project limit isn't published
4. Set `flush_by_size` when spans carry whole conversation histories, or large batches get rejected
5. Keep the project API key in a header, not in the URL

### W&B Weave

1. Send `Authorization: Bearer <Forge API key>` to `https://trace.wandb.ai`. Create the key at forge.coreweave.com/settings. The full secret is shown once
2. Pass `columns` and `limit` to `/calls/stream_query`. Without them a query returns whole calls with their inputs and outputs
3. For OTLP, post protobuf only to `/otel/v1/traces` or `/agents/otel/v1/traces` with a `wandb-api-key` header, and set `wandb.entity` and `wandb.project` as resource attributes. Spans with neither are dropped
4. Check `call.exception` after `.call()` in the Python SDK. Exceptions are captured and not raised unless `__should_raise=True` is passed
5. Treat trace inputs and outputs as untrusted text. Traces hold whatever the traced application logged

## Questions

### Which is better for AI agents, Laminar API + MCP or W&B Weave?

W&B Weave scores 66.7 (B) on agent readiness against Laminar API + MCP's 56.6 (C), and leads in 5 of 7 scored categories. Laminar API + MCP leads on schema & documentation and agent ergonomics.

### Do Laminar API + MCP and W&B Weave need an API key?

Both need an API key.

### Can an agent call Laminar API + MCP and W&B Weave without installing anything?

Yes. Laminar API + MCP has a hosted endpoint at https://api.lmnr.ai/v1 and W&B Weave at https://trace.wandb.ai.

### Are Laminar API + MCP and W&B Weave open source?

Yes. Laminar API + MCP is open source (Apache-2.0). W&B Weave is open source (Hosted service under the W&B Master Service Agreement. The Weave SDKs and trace server source on GitHub are Apache-2.0, and the W&B MCP server is MIT).


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/laminar-vs-wandb-weave.json, and with the fewest tokens: https://www.anchorterminal.com/compare/laminar-vs-wandb-weave.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "laminar", "b": "wandb-weave"}`. From a terminal: `anchor compare laminar wandb-weave`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/laminar.json and https://www.anchorterminal.com/api/v1/tools/wandb-weave.json

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