Billing

Checkfu accounts for agent runtime, managed model use, separately priced Managed Tools, and governed Web Search. Each follows the terms selected for the work. Usage records what was metered; a charge records the customer amount. An invoice or payment is a separate commercial record. With API-key BYOK, the model provider bills your account and Checkfu creates no managed-model charge. Runtime, separately priced Tools, and governed Web Search still follow their own terms. Customer-operated Cloudflare also does not, by itself, remove the Checkfu runtime fee. Physical compute and storage costs are separate from the Session’s runtime meter.

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Running time

Suppose a support Session has two overlapping Runs, while a second Session works independently: Session A records six running minutes, not eight. Session B records two of its own: eight Session-minutes in total. If A then waits for approval from 10:06 to 10:10 with no Run running, those four minutes add no Session runtime. Its machine or storage may still incur physical costs during that wait. Session runtime producer versions 2 and 3 record the union of its running intervals: overlapping Runs in one Session count once, while different Sessions count separately. Historical producer version 1 retains its per-Run intervals; read its original producer version rather than reinterpret that history as a union. A Run waiting for approval or rescheduling does not itself add running time. If another Run in that Session is still running, the Session’s interval continues; it closes when no Run remains running. Terminal and settled time do not add running time. If a crash leaves a running interval without an authoritative close, its end remains unresolved and the never-closed interval remains unbilled. Restart, erasure, or a missing response does not supply a billable end timestamp. Unresolved supplier costs are not thereby zero. Accounting retains the original interval identity for recovery; an accepted close is retried against that same Usage identity rather than billed again. These rules do not establish that a particular outage has been reconciled. See Sessions and Runs for lifecycle events and Attribute Usage for retained runtime versions and attribution.

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The authority split

Use the Usage guide to query metered work and its charges. A Usage row, Budget reservation, billed amount, credit, invoice, and collected payment answer different questions. None alone establishes all the others. The append-only Usage ledger is the metering authority. A trace may project some of the same activity, but it can be sampled, delayed, redacted, or absent. Checkfu does not reconstruct authoritative Usage from trace spans, message text, response timing, or a provider dashboard.

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Model supply and credential custody

A Session freezes its AgentVersion and Environment. The Agent’s model config determines which model source Session admission freezes: a model that pins a Workspace credential (model.model_credential_id) uses that credential, and an unpinned managed model uses platform supply.

• Workspace credential: Checkfu records model Usage and creates no managed-model charge because the provider bills the Workspace’s account. This removes managed-model charges only; Session runtime and separately priced tools still follow their own terms.
• Platform supply: Checkfu uses an admitted provider account owned by Checkfu and records the resulting platform charge. Text generation runs on Checkfu’s OpenRouter account, with each managed route pinned to the price ceiling its rate card was reviewed at; image generation runs on fal.

A Workspace-selected credential never silently falls back to platform supply. Starting a new Session with a revoked or rejected pinned credential is refused with HTTP 409 validation.conflict; update or rotate the credential before starting again. If the credential is rejected or revoked for an already-admitted provider effect, that effect fails closed with model.credential_rejected. Selecting platform supply again is an explicit configuration change for a later admission. Raw provider credentials stay in trusted custody. They are not fields in model context, harness configuration, Session events, Usage rows, or sandbox workloads. The trusted provider edge attaches the credential only after the live authorization, policy, approval, Budget, and revocation checks have allowed the exact effect. See Security posture.

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Current metering rules

Usage records activity and its accounting basis. An immutable charge records the customer amount; delivery to Autumn and payment are separate steps. A pending billing projection does not mean that the work was free or that payment has completed. If a delivery loses its response, acceptance can remain unknown. An empty reconciliation scan or an expired delivery lease does not establish that Autumn rejected the original event. Checkfu retains the original charge and unresolved delivery for reconciliation; these observations do not authorize another debit. For recorded model-token Usage, measurement.basis: "admitted_maximum" means the counters are the conservative maximum admitted before dispatch because no provider receipt was recovered. These counters are an unreconciled estimate, not provider-measured consumption. Read the original charge separately; this basis does not prove supplier acceptance, Autumn delivery, or payment. Customer charges retain their original rate or formula version and exact amount. A later rate change or provider change does not rewrite an existing charge. Supplier costs are separate accounting facts; they are not customer amounts. A correction links to the original charge and records an absolute target amount and a signed adjustment. The original charge remains in history. An adjustment’s delivery status does not establish that a credit or cash refund has completed. Usage without a recorded charge does not, by itself, establish a zero price. Check its supply class and applicable terms before treating it as BYOK or free work. A missing financial fact and an undelivered charge are different states.

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Read the charge for a Usage entry

Where the Usage read capability is available, request GET /v1/usage/{usage_entry_id}/charge using the original Usage ID. The SDK method is client.usage.charges.retrieve(usage_entry_id, { limit: 20 }). This authenticated read returns the retained customer charge and its pricing version, linked corrections, and the original charge’s projection state. It does not purchase work or activate commercial billing. Follow corrections.next_page as the next request’s page, keeping the same Usage ID, Workspace and limit. A page is not necessarily the complete correction history. Each correction includes an absolute target and a signed adjustment; do not add the absolute targets together. The response’s projection describes the original charge, not delivery of each correction or payment. A null charge means no charge is recorded in this read; it does not prove that the work was free.

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Rate versions

The current accounting contracts retain these rates and exclusions. They are not a universally activated price list; the admitted terms and commercial availability govern each operation: Native built-in search does not currently produce the governed web_search meter. It is not billed as a governed Web Search request; runtime and model usage still follow their own terms. The governed-search rate describes the existing accounting contract, not universal availability or commercial activation. The Session-owned native model gateway requires an explicitly selected, independently frozen customer rate card for managed admission. If that selection is missing, admission refuses before creating managed supplier or customer holds. The older model-plane gateway can still use the default supplier-times-1.05 formula shown above; the Session-owned native gateway does not fall back to it. Historical charges retain their original terms. Native Sessions retain their runtime financial disposition at creation. Closing or replaying an interval uses those original terms, not the current billing switch. The older runtime path uses its enabled-runtime-billing setting. A disabled native disposition records running time with no billed amount; it is not permission to enable commercial billing later or reprice that interval. Managed Tool catalog publication describes a release, not a priced purchase admission. The exact-release response reports customer_terms_status: available includes the observed fixed price, billing basis, empty-result policy, rate-card version and effective window. not_installed or revoked returns customer_terms: null, which means no offered quote, not free execution. These read-only terms do not reserve funds, grant execution permission or authorize a purchase. Admission retains the applicable original terms separately from catalog discovery. The product direction is about $0.08 per active Session-hour and no Checkfu markup on managed tokens. That direction is not commercial activation. Independent customer rate cards freeze retail amounts separately from supplier costs for the selected provider/model pair. Cross-provider model identity mapping is not yet qualified; changing that pair requires a reviewed mapping and retained customer price terms. Selecting cards and activating commercial billing are separate steps; the direction does not change existing charges. Gateway funding and payment-fee treatment require explicit terms. Supplier cost estimates, observed liabilities, reconciled supplier invoices, and supplier payments remain separate from the customer charge. Unknown liability survives a provider receipt or idempotency window expiring; expiry does not authorize a fresh paid attempt. Provider-reported model counters are normalized into immutable model Usage facts. Actual work remains Usage even when a Session later fails, is cancelled, or becomes subject to an erasure request. Sandbox compute and snapshot retention can be recorded for unit economics even when they are not invoiced. Their presence in Usage does not make them Budget-enforceable or billable. Included compute and Computer premiums remain undecided; physical compute, idle residency, and storage do not become Session runtime charges merely because they incur supplier costs. When a Principal is erased, retained accounting facts may remain identifiable or pseudonymous through Workspace and original accounting identifiers. The direct Principal link is removed and a generated subject reference is retained; that reference does not establish anonymity. Erasure must not change historical Workspace totals. Current end-to-end erasure limits are described in Retention and zero-data retention.

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Four independent refusal gates

All applicable gates must allow a request. Raising a Budget does not repair payment or entitlement. Commercial entitlement does not override an ActionPolicy, a revoked credential, or a Workspace quota.

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Budget admission and stopping

A Budget reserves capacity before work and settles against authoritative Usage. Live runtime checks include elapsed time in the Session’s still-open running interval within the Budget’s scope and window. This counts toward session_runtime_ms and, when billable under the retained runtime terms, the runtime share of total_spend. A Session cannot avoid its Budget merely by keeping the interval open. Open accrual is an enforcement projection, not billed runtime Usage. Billed runtime Usage requires an authoritative close. The closed fact replaces the open projection, so the same interval is not counted twice. A prior reservation or approval does not grant unlimited future spending. Customer Budget capacity and supplier capacity are separate; reserving one does not reserve the other. Spend thresholds use integer micro-USD. BYOK removes managed-model charges from total_spend, not model-cost facts from model_spend. Neither metric proves supplier payment or payment of a customer invoice. See Enforce a Principal Budget for the request shape and scope. A hard threshold can block new admission, interrupt an in-flight turn, or pause a Session according to its configured action and supported path. pause_session is valid only for a Session-scoped Budget. Traces do not enforce these limits. A stop request is not a stop acknowledgment. Observe the original Run’s actual stopped or terminal outcome and the Session’s authoritative runtime state. Its interval closes only when no Run remains running. Do not use a Budget response, client disconnect, or missing result as the stop time. An in-flight provider operation may already have incurred cost; stopping the Run cannot undo it. Budget enforcement is not a promise of an instantaneous hard cap across every provider or physical resource. For native managed-model work, a total_spend Budget includes the retained maximum customer exposure while settlement is incomplete. This is a spending control, not an invoice charge or a payment. Expiry or release of the execution hold does not erase that exposure: the original Usage and its matching frozen customer charge must both be recorded before the actual charge replaces it. Usage alone, or a charge for a different original request, customer card, or credential generation, does not release the bound. An uncertain outcome can therefore keep capacity unavailable until original financial evidence is recovered. Retrying must recover that original work rather than buy it again. An authenticated BYOK model association has zero managed-model customer exposure. Session runtime and separately priced tools still count according to their own admitted terms; BYOK does not remove those charges or Budget limits.

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Typed commercial routes

The current contract defines routes such as: These shapes are API contracts, not a support claim. Call the authenticated support endpoint and inspect available and missing_prerequisites before showing a commercial action.

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Next steps