The Platform PM

Key concepts

Field Guide

Models and inference: what AI runs on

04

Key concepts

8 min read · Chapter 4 of 10

01

Entity and identity

What is the unit of record, and how do we know it is the same one?

"The model" has at least three parts: a family (Sonnet, gpt-6.1-sol), a snapshot ID (the exact version), and the host or deployment that serves it. On Azure you call a deployment name you created, and on Bedrock the same Claude model has its own ID and its own retirement date. Open-weight models add the precision and serving stack, which is why OpenRouter lets you filter hosts by quantization. The billing identity is a tree of organization, workspace or project, and API key, and rate limits attach to the organization (Anthropic, OpenAI) or the project (Google), per model, so teams in one organization share its headroom.

The law names its own entities. Under the EU AI Act the "provider" places a model on the market and the "deployer" uses it, and a company that fine-tunes with more than a third of the original training compute becomes the provider of the result. An IP indemnity keys on plan, service and model together, so one API key can be covered for one model and not another. US export rules now follow a company's ultimate parent, wherever its subsidiary is registered (guidance of May 31, 2026).

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02

State and lifecycle

What states exist, and what moves an entity between them?

A request goes from admitted to queued, prefilling, decoding and streaming, and ends complete, incomplete or failed. A model goes from preview to generally available, legacy, deprecated (still works, retirement date set) and retired. A prompt cache is written, stays warm while used, and dies when it expires or when the prefix, tools or reasoning settings change. An account climbs tiers with spend history and pauses at its spend cap until the next month. Capacity goes from contracted to built, energized and allocated.

Retirement clocks differ by vendor and are getting shorter at some:

VendorTypical notice before retirementNotes
AnthropicAt least 60 days; 60-62 days for every 2026 noticeDown from 181-189 days in 2025; Opus 4.1 lived exactly 12 months
OpenAIAt least 6 months for generally available models, 3 for specialized ones, about 2 weeks for previewsA restricted cyber model got 20 days in September 2026
Google (Gemini API)Dates are "earliest possible"; previews retire 2-4 months after releaseSome previews run in production for months
Microsoft Foundry18-month lifecycle for most generally available models, at least 60 days' noticeStandard deployments auto-upgrade; "retirement dates aren't extendable"
AWS Bedrock"End of life no sooner than" a stated date; Legacy for 6 months or 45 daysLegacy blocks new customers and provisioned throughput
MistralNo formal policy; about 24 days observed for one model
Self-hosted open weightsNoneHosted versions at clouds still retire

The same model can retire on different dates at the lab and at each cloud. Products retire too: OpenAI ends its Assistants API, hosted evals and self-serve fine-tuning jobs between August 2026 and January 2027.

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03

System of record and ledger

Who owns the truth, and how do systems reconcile?

FactSystem of record
What one call usedThe provider's usage record per request: input, cache write, cache read, output, tier, region
What the company spentThe provider's usage and cost API, the gateway's log and the cloud invoice, which rarely agree
How much headroom is leftRate-limit headers on every response
Whether the provider was upIts status page, which the provider writes and which can lag
What a lab has contracted to buyBacklog at the clouds; take-or-pay schedules in filings

On cloud marketplaces Anthropic converts usage into consumption units of $0.01 and reports them to AWS or Azure, so a discount shows up as fewer units. A private lab's "run-rate" is a recent month times twelve. Your own gateway log is the only record of errors from your side, and it's the evidence an SLA claim needs.

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04

Rules and policy

What logic decides outcomes, and who can change it?

Access is rationed by rules the provider writes and can change:

Anthropic

Tiers
Evaluation, Start, Build, Scale, Custom
Monthly spend cap
$500 / $1,000 / $200,000
Example limit at the top self-serve tier
Opus 5.5: 10,000 requests and 10 million input tokens a minute; Fable 5.x: 4,000 and 4 million

OpenAI

Tiers
Free, Build, Launch, Grow (after $5, $100 and $500 of purchases)
Monthly spend cap
$100 / $500 / $5,000 / $200,000
Example limit at the top self-serve tier
gpt-6 Astra, Sol and Terra: 15,000 requests and 40 million tokens a minute

Google (Gemini API)

Tiers
Free, Tiers 1-3 (by spend and account age)
Monthly spend cap
$250 to $100,000 or more, plus a 10-minute spend limit
Example limit at the top self-serve tier
Per project, per model

The top model gets the tightest limit, and Anthropic calls its limits "maximum allowed usage, not guaranteed minimums". New organizations start lower "to prevent fraud and abuse", and fast ramps hit acceleration limits. Gateways add the customer's own policy (route by price or speed, cap the price per token, use only zero-retention hosts, set budgets per team), and the labs' usage policies restrict high-stakes uses without human review.

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05

Effective dating

Which version of the rule applied at that moment?

Dates I'd keep on a calendar as of October 2026:

ChangeEffectiveStatus (Oct 2026)
EU AI Act duties for general-purpose model providersAugust 2, 2025In force
California SB 53 for frontier developersJanuary 1, 2026In force
H200-class chips to China move to case-by-case reviewJanuary 13, 2026In force; China limits imports
EU AI Office enforcement powers, including finesAugust 2, 2026In force; first requests September 1
Claude Sonnet 4.5 retiresNovember 30, 2026Upcoming
EU Product Liability Directive covers softwareDecember 9, 2026Upcoming
OpenAI GPT-5 and o3 snapshots retireDecember 11, 2026Upcoming
Gemini 3.6-3.8 Flash prices doubleJanuary 1, 2027Upcoming
New York RAISE ActJanuary 1, 2027 (some sources say July 1)Upcoming
Older general-purpose models must comply with the AI ActAugust 2, 2027Upcoming

Some dates float. Retirement dates are "not sooner than" (Anthropic, AWS) or "earliest possible" (Google), and introductory prices can end or be made permanent: Anthropic kept Sonnet 5's and cancelled a rise planned for September 1, 2026. DeepSeek even prices by time of day.

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06

Interfaces and standards

What format and protocol do counterparties speak?

OpenAI's Chat Completions and Responses formats are the de facto interface: Bedrock exposes them ("change the base URL and API key"), most inference providers do, and Anthropic runs an OpenAI-compatible endpoint next to its own Messages API. That makes switching mechanically cheap. Everything around the call is unstandardized: usage fields, rate-limit headers, deprecation metadata and reasoning controls differ per provider. Tokenizers differ too, so the same text can be about 30-35% more tokens on Anthropic's newest models than on its older ones.

Measurement is its own layer. Artificial Analysis measures time to the first token and output speed from one server over 72 hours, MLPerf audits hardware results that vendors submit, and SemiAnalysis's InferenceX turns benchmarks into cost per million tokens. Model makers have started checking hosts: Moonshot publishes a Kimi Vendor Verifier and OpenAI added a compatibility test for gpt-oss. Below the token the units change again: GPU-hours for renting chips, gigawatts of power capacity for compute deals, and megawatt-days in power markets.

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07

Networks and counterparties

Who sits between us and the outcome, and what do they want?

PartyWhat they controlWhat they earn
LabQuality, prices, limits, retention, retirementsTokens, subscriptions, enterprise deals
Cloud platformProcurement, regions, its own SLA and datesResold tokens; commitments drawn down
Inference providerSpeed and price for open modelsTokens, dedicated endpoints, GPU rental
GPU cloudEnergized capacityMulti-year take-or-pay contracts
Chip makerAllocation of new chipsHardware at about 74% gross margin (Nvidia)
GatewayRouting and budgetsA small fee, or nothing (open source)
Grid operator and utilityPower and connection datesCapacity payments, set by auction

Money flows down the chain and equity flows back up it: Nvidia invests in OpenAI and in GPU clouds and providers, Amazon and Google in Anthropic, Microsoft owns about 27% of OpenAI and has invested in Anthropic, and AMD gave OpenAI warrants for up to 160 million of its shares. Amazon sells Claude on Bedrock, holds Anthropic notes, supplies it Trainium and sells its own Nova models, all at once.

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08

Regulatory layering

Jurisdiction × activity × entity type: is it a license or a certification?

Model makers

US
California SB 53 (frontier developers above 10^26 operations); New York RAISE from 2027
EU
AI Act duties for general-purpose models; Code of Practice
China and elsewhere
Chinese labs mostly outside the EU Code

Chips and weights

US
Export controls: case-by-case H200 licences for China, approved entities in the UAE
EU
China and elsewhere
Beijing approves or blocks imports

Data

US
Sector rules; court preservation orders
EU
GDPR; residency demands
China and elsewhere
Data stays in-country in many sovereign deals

Products

US
Deployer liability (case law)
EU
Product Liability Directive from December 9, 2026
China and elsewhere

The same model reached through the lab, Bedrock or Vertex can come with different retention, residency, SLA and indemnity terms, so the route is a legal choice too. For most builders the law arrives through vendor terms and procurement questionnaires.

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09

Exceptions and reversals

What goes wrong, and how is it undone?

Rate limit or spend cap hit

Who starts it
The provider's limiter
Clock
Seconds, or until the 1st of next month
The way back
Back off with jitter; fail over; ask for a tier increase

Model retired

Who starts it
The lab or cloud
Clock
60 days to 6 months; 20 days seen
The way back
Re-test on the replacement; pin the next snapshot

Bad serving change

Who starts it
The provider
Clock
Hours to weeks to detect
The way back
Provider rollback (GPT-4o's sycophantic update came out about four days after release); your own evals

Price step-up

Who starts it
The provider
Clock
A dated announcement, or a promotion ending
The way back
Route elsewhere; renegotiate

Capacity product withdrawn

Who starts it
The provider
Clock
Immediate for new buyers
The way back
Existing contracts honoured; buy elsewhere

Compute deal cancelled or reshaped

Who starts it
Either party
Clock
90 days for xAI's capacity to Anthropic; years for take-or-pay
The way back
Other sites, other chips

Rule reversed

Who starts it
A government
Clock
Months
The way back
Switchable architecture; exit rights in contracts

Reversals run both ways. OpenAI's "$1.4 trillion" of compute ambitions became about $600 billion through 2030 in reporting by February 2026, and the expansion of the Abilene site beyond 1.2 GW was dropped. Export rules went from ban to unban to a revenue share that was never codified, all within 2025.

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10

Liability allocation

When it fails, who pays?

FailureWho absorbs itMechanism
OutageThe builder, minus a small credit where an SLA existsBedrock: 99.9% per region, credits of 10-100% of that region's charges as future credit; lab standard tiers: best effort, no credit
Silent quality dropThe builderNo SLA found that counts wrong answers as downtime
Retirement and migrationThe builderNotice periods; no compensation
Copyright claim on an outputThe vendor, if the indemnity's conditions are metPaid plan, covered model, output unmodified, filters on; usually outside the liability cap
Copyright claim over training dataThe labBartz, the New York Times case; reaches builders only through prices
Harm from an answerThe deployer by defaultAir Canada's chatbot case; consumer cases against model makers are pending or settled
Unused computeThe lab, then its investorsTake-or-pay contracts: about 80% of Anthropic's commitments, as reported
GPU cloud failureLenders, then customers mid-contractDebt against contracts

Builders carry price and capacity risk, labs carry volume risk, GPU clouds carry financing and obsolescence risk, and household electricity customers carry part of the grid cost. Liability caps in the labs' and clouds' terms are typically 12 months of fees.

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