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AI · head to head

Anthropic API vs Seldon

Anthropic API logo

Anthropic API

AI

Claude API for developers

From
On request
Free plan
No
Full reviewWebsite
Seldon logo

Seldon

Machine Learning

Kubernetes model serving whose current version is licensed under the Business Source Licence

From
Free
Free plan
Yes
Full reviewWebsite

The short version

  • Only Seldon has a free tier, so it costs nothing to try first.
  • Each has a real cost: Anthropic API pricing varies significantly by model tier; Seldon seldon Core v2 is under the Business Source Licence rather than Apache 2.0, so production use requires a commercial agreement, and a team that evaluated it believing it was open source discovers the licence is the blocker exactly when the project is ready to ship.
  • They diverge on capability: Anthropic API covers Multiple models, Seldon covers Kubernetes custom resources.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Anthropic API and Seldon actually diverge.

Attributes where Anthropic API and Seldon differ
AttributeAnthropic APISeldon
Starting priceOn requestFree
Pricing modelusage-basedfreemium
Free tierNoYes
PlatformsApiLinux
CategoryAIMachine Learning
Founded20212014

Identical on both: user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Anthropic API

  • Multiple models
  • 200K context
  • Vision capabilities
  • Function calling
  • REST API
  • SDKs
  • Amazon Bedrock
  • Google Vertex

Only in Seldon

  • Kubernetes custom resources
  • Inference graphs
  • Traffic strategies
  • Open Inference Protocol
  • Alibi Explain
  • Alibi Detect
  • Kafka-backed pipelines in v2
  • Commercial control plane

What people use each for

The jobs each tool is most often brought in to do.

Anthropic API

  • AI agent developmentnot Seldon
  • LLM-powered API integrationnot Seldon
  • Batch processing for cost optimizationnot Seldon

Seldon

  • Serving an ensemble or a multi-stage inference path as one versioned deployment rather than as a chain of separate servicesnot Anthropic API
  • Running genuine production experiments where a share of live traffic goes to a candidate model and the results are comparednot Anthropic API
  • Regulated environments needing explanations and drift monitoring attached to the served model rather than bolted on laternot Anthropic API
  • Organisations with an established Kubernetes platform team who want serving expressed as manifests under existing deployment controlsnot Anthropic API

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Anthropic API

  • Pricing varies significantly by model tier
  • Batch processing and Fast Mode add additional surcharges
  • US-only inference costs 1.1x standard pricing

Seldon

  • Seldon Core v2 is under the Business Source Licence rather than Apache 2.0, so production use requires a commercial agreement, and a team that evaluated it believing it was open source discovers the licence is the blocker exactly when the project is ready to ship.
  • Core v1 remains Apache 2.0 but is in maintenance, so taking the free route means running software that receives no new development while the architecture it belongs to moves on without it.
  • Version 2 is a different system rather than a newer release, with different custom resources, a scheduler component and a Kafka-based pipeline model, so migrating from v1 is a re-implementation of every deployment manifest rather than an upgrade.
  • Kafka is a dependency for v2 pipelines, so an organisation that does not already operate it takes on a distributed log with its own storage, retention, rebalancing and failure modes purely in order to serve models.
  • Everything assumes Kubernetes fluency and the failure modes are Kubernetes failure modes, custom resource version mismatches, an operator that will not reconcile, admission webhooks and resource limits terminating an inference pod mid-request, so it needs a platform engineer rather than a data scientist.

Pricing, plan by plan

Anthropic API

On request
  • Fable 5$undefined/mo
    • Input: $10/MTok
    • Output: $50/MTok
    • Prompt caching Write: $12.50/MTok
  • Opus 5$undefined/mo
    • Input: $5/MTok
    • Output: $25/MTok
    • Prompt caching Write: $6.25/MTok
  • Sonnet 5$undefined/mo
    • Input: $2/MTok
    • Output: $10/MTok
    • Prompt caching Write: $2.50/MTok
  • Haiku 4.5$undefined/mo
    • Input: $1/MTok
    • Output: $5/MTok
    • Prompt caching Write: $1.25/MTok

Seldon

Free
  • Seldon CoreFree
    • Open source
    • Kubernetes deployment
    • Model serving
  • Seldon DeployFree
    • Enterprise features
    • GUI
    • Monitoring

Which should you pick?

Choose Anthropic API if

  • You need multiple models.
  • You work on Api.
  • You also want 200k context.
Anthropic API review

Choose Seldon if

  • You need kubernetes custom resources.
  • You want to start without paying.
  • You work on Linux.
  • You also want inference graphs.
Seldon review

Questions people ask

Is Anthropic API or Seldon better?
Neither clearly leads. Anthropic API starts at On request and Seldon at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Anthropic API or Seldon?
Seldon has a free tier; the other does not. Paid plans start at On request for Anthropic API and Free for Seldon.
Does Anthropic API or Seldon run on more platforms?
Anthropic API runs on Api. Seldon runs on Linux.
Can I use Seldon for free?
Yes. Seldon has a free tier, so you can try it without paying. Anthropic API starts at On request.
What is Anthropic API best used for?
Anthropic API is most often used for ai agent development, llm-powered api integration, batch processing for cost optimization. Of those, ai agent development and llm-powered api integration are not what Seldon is typically brought in for.
What can Anthropic API do that Seldon cannot?
Anthropic API covers Multiple models, 200K context, Vision capabilities, Function calling. Seldon covers Kubernetes custom resources, Inference graphs, Traffic strategies, Open Inference Protocol.

Answered from the vendors’ own pages

Anthropic API: How much does the Claude API cost?

Claude API uses pay-as-you-go pricing per million tokens (MTok). Haiku 4.5 costs $1 input/$5 output per MTok; Sonnet 5 costs $2 input/$10 output; Opus 5 costs $5 input/$25 output; Fable 5 costs $10 input/$50 output per MTok.

Source
Seldon: Is Seldon open source?

Partly, and this is the thing to check before you build on it. Core v1 is Apache 2.0 but in maintenance. Core v2 was moved to the Business Source Licence in 2024, which allows evaluation but not unlicensed production use. Verify the current licence of each component you intend to run, including MLServer and the Alibi libraries.

Anthropic API: What discounts does the Claude API offer?

Batch processing saves 50% on API costs. Prompt caching reduces token costs by up to 90% for cached reads (charged at 80% discount compared to standard rates). Fast Mode for Opus 5 costs 2x standard pricing for up to 2.5x faster response speeds.

Source
Seldon: What is the difference between v1 and v2?

Architecture, not just version number. v2 introduces a scheduler, a different set of custom resources and Kafka-backed pipelines. Manifests, mental model and operations all change, so treat a move as a project.

Anthropic API: Does the Claude API have different billing models?

Self-serve access uses usage-based tiers with automatic rate limit increases as volume grows. Enterprise customers receive custom rate limits, monthly invoice billing, and hands-on support at negotiated pricing.

Source
Seldon: Do I need Kubernetes?

Yes. It is a Kubernetes-native system and there is no meaningful deployment without a cluster and someone competent to run it.

Anthropic API: How much extra does US-only inference cost on the Claude API?

US-only inference costs 1.1x pricing for input and output tokens across all model tiers compared to standard multi-region pricing.

Source
Seldon: What is MLServer?

Seldon's Python inference server implementing the Open Inference Protocol, usable inside Seldon deployments or on its own. Check its current licence alongside Core's, since the company has moved projects onto the Business Source Licence.

Seldon: Do I have to run Kafka?

For v2 pipelines, yes. If you only need single models served, that dependency is a large amount of infrastructure for the benefit, and a simpler serving layer may be the better answer.

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