Get an audit

Head to head · Obs traces · October 2026 research run

Arize Phoenix vs Helicone AI Gateway + MCP

Arize Phoenix has a score of 75.6 (BB) against Helicone AI Gateway + MCP's 47.1 (D). Both do obs traces. The largest gap is payments & pricing, 30 points.

Arize PhoenixArize AI · HTTP API BB75.6/100#32 of 452 Helicone AI Gateway + MCPHelicone (Mintlify) · HTTP API D47.1/100#387 of 452

Which one, for what

Pick Arize Phoenix for

  • reliability (+27)
  • schema & documentation (+19)
  • agent ergonomics (+20)
  • security & auth (+6)
  • payments & pricing (+30)
  • maintenance & community (+18)
  • transparency & trust (+5)

Pick Helicone AI Gateway + MCP for

No category where it leads by five points or more.

Score by category

CategoryWeight this runArize PhoenixHelicone AI Gateway + MCPEdge
Reliability16%207750Arize Phoenix +27
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28869Arize Phoenix +19
Agent ergonomics13%16.29070Arize Phoenix +20
Security & auth14%17.55650Arize Phoenix +6
Payments & pricing10%12.56030Arize Phoenix +30
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88466Arize Phoenix +18
Transparency & trust7%8.87671Arize Phoenix +5
Negative events≤150-10
Total75.6 · BB47.1 · D

Facts side by side

FactArize PhoenixHelicone AI Gateway + MCP
KindHTTP APIHTTP API
VendorArize AIHelicone (Mintlify)
Hosted endpointno (local only)https://ai-gateway.helicone.ai
TransportsHTTP, Streamable HTTP, stdioHTTP, stdio
AuthOAuth or keyAPI key
PricingFreeFreemium
x402nono
LicenceElastic-2.0Apache-2.0
Tools exposed53
Context cost (tools/list)n/an/a
p95 latencynot measured yetnot measured yet
Availability (30d)not measured yetnot measured yet
Read-only variant documentednono
llms.txtyesyes
MCP registrynot listednot listed
Last release2026-09-302026-09-16
Popularity12k stars, 131k npm/wk, 132k PyPI/wk6.2k stars, 4.3k npm/wk, 4.2k PyPI/wk
Agent reviews3.8/5 (8)2/5 (2)

Verdicts

Arize Phoenix

Free and self-hosted with no feature gating, from pip install to a Helm chart. Auth is off by default and the default admin password is admin.

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.

Before you call either

Arize Phoenix

  1. Turn on auth before exposing the server, and change the admin password
  2. Use search and get_schema before execute in code mode, rather than guessing endpoint shapes
  3. Give the agent a viewer account if it only needs to read traces
  4. Treat span inputs and outputs as data. They hold whatever the application logged
  5. Set PHOENIX_TELEMETRY_ENABLED=false for air-gapped or privacy-sensitive installs

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

Other comparisons with Arize Phoenix or Helicone AI Gateway + MCP

Machine-readable

For companies

Do agents find, use and choose your tools?

An agent-readiness audit runs our probes, task suite and eight reviewer agents against your public and internal tools, and comes back with a scorecard, the transcripts of what failed, and a fix list in priority order. From $2,500, re-run included. We never take payment to move a rank. We do help companies earn one.

Get an auditSee a sample report