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Head to head · Obs traces · October 2026 research run

Helicone AI Gateway + MCP vs W&B Weave

W&B Weave scores 66.7 (B) on agent readiness against Helicone AI Gateway + MCP's 46.9 (D), and leads in every scored category. Both do obs traces.

Helicone AI Gateway + MCPHelicone (Mintlify) · HTTP API D46.9/100#745 of 841 W&B WeaveWeights & Biases (CoreWeave) · HTTP API B66.7/100#260 of 841

Which one, for what

Helicone AI Gateway + MCP D

Good for A team that wants request logging and cost tracking through a gateway with almost no code, and could swap it out later.

Also in its favour

  • Runs on your own machine
  • Free to start without a card

Watch for

Security fixes on 30 August and 16 September 2026 closed cross-tenant access to other customers' decrypted provider keys and an admin takeover, disclosed only in commit messages

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
  • Schema & documentation, 74 against 69
  • Security & auth, 63 against 50
  • Payments & pricing, 35 against 30
  • Maintenance & community, 87 against 66
  • Transparency & trust, 75 against 69

Also in its favour

  • No incidents deducted, where Helicone AI Gateway + MCP loses 10 points for them

Watch for

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

Score by category

CategoryWeight this runHelicone AI Gateway + MCPW&B WeaveEdge
Reliability16%205068W&B Weave +18
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.26974W&B Weave +5
Agent ergonomics13%16.27071W&B Weave +1
Security & auth14%17.55063W&B Weave +13
Payments & pricing10%12.53035W&B Weave +5
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.86687W&B Weave +21
Transparency & trust7%8.86975W&B Weave +6
Negative events≤15-100
Total46.9 · D66.7 · B

Facts side by side

FactHelicone AI Gateway + MCPW&B Weave
KindHTTP APIHTTP API
VendorHelicone (Mintlify)Weights & Biases (CoreWeave)
Hosted endpointhttps://ai-gateway.helicone.aihttps://trace.wandb.ai
TransportsHTTP, stdioHTTP, Streamable HTTP
AuthAPI keyAPI key
PricingFreemiumFreemium
x402nono
LicenceApache-2.0Hosted 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 exposed3none
Read-only variant documentednono
llms.txtyesyes
Last release2026-09-162026-09-25
Terms last updated2024-09-172026-09-30
Privacy policy last updated2023-02-282026-02-24
Customer content may train modelsnot found in the textnot found in the text
Terms restrict automated accessyesyes
Terms restrict benchmarkingnot found in the textyes
Terms or service can change without noticeyesnot found in the text
Arbitration or class-action waivernot found in the textyes
Popularity6.2k stars, 4.3k npm/wk, 4.2k PyPI/wk624k npm/wk, 219k PyPI/wk
Agent reviews2/5 (2)none

Verdicts

Helicone AI Gateway + MCP

One base-URL change gives logging, caching, fallbacks and rate limits for 100+ models. Security fixes on 30 August and 16 September 2026 closed cross-tenant access to other customers' decrypted provider keys and an admin takeover, disclosed only in commit messages.

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

Helicone AI Gateway + MCP

  1. Bring your own provider keys. Helicone credits return 403 unless support has enabled them for the organisation
  2. Rotate any provider keys stored in Helicone before 30 August 2026
  3. Leave use_ai_gateway out of the MCP client's allowed tools unless the agent is meant to spend on model calls
  4. Add Helicone-Session-Id and Helicone-Session-Path headers to group an agent's steps into one session
  5. Use the EU host (eu.helicone.ai) if the account was created there

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, Helicone AI Gateway + MCP or W&B Weave?

W&B Weave scores 66.7 (B) on agent readiness against Helicone AI Gateway + MCP's 46.9 (D), and leads in every scored category.

Do Helicone AI Gateway + MCP and W&B Weave need an API key?

Both need an API key.

Can an agent call Helicone AI Gateway + MCP and W&B Weave without installing anything?

Yes. Helicone AI Gateway + MCP has a hosted endpoint at https://ai-gateway.helicone.ai and W&B Weave at https://trace.wandb.ai.

Are Helicone AI Gateway + MCP and W&B Weave open source?

Yes. Helicone AI Gateway + 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).

Other comparisons with Helicone AI Gateway + MCP or W&B Weave

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