# Step Credits, Tokens & Storage > Detailed consumption rules for workflow Step credits, hosted Glow AI model tokens, and persistent file storage. Every automation in Glow draws from three transparent meters: **Step credits**, **Glow AI tokens**, and **Retained storage**. Understanding how these meters operate allows you to accurately forecast costs and design efficient automations. --- ## 1. Step Credits Step credits measure standard workflow execution. Each step reserves capacity before execution and settles based on the actual work performed. 1. Step Triggered → 2. Atomic 1-Credit Reservation → 3. Execution & Settlement ### Execution outcomes and fair charging Glow uses a state-safe reservation lifecycle so you are charged only for actual work performed: **Outcome: Success (`pass`) · 1 Step Credit Deducted** The step completed all work successfully. The initial 1-credit reservation is settled and deducted from your monthly allowance. - **Charge:** **1 Step credit**. - **Settlement state:** `Settled`. - **Real-world scenario:** A Slack message, CRM update, or HTTP Request sent and acknowledged with `200 OK`. **Outcome: Pre-Work Error (`FailedUncharged`) · 0 Credits (Free)** The step failed before performing external chargeable work (e.g. invalid input mapping, unconfigured connection credentials). The reservation is released immediately. - **Charge:** **0 credits (Free)**. - **Settlement state:** `Released`. - **Real-world scenario:** An API step with an invalid authentication token fails validation before dispatching to the external service. **Outcome: Partial Batch Execution (`FailedChargeable`) · Proportional Settlement** For batch loops ([Run for each item](/build/action-steps/loops/run-for-each-item) or [Repeater](/build/action-steps/loops/repeater)), credits settle based on the exact number of item passes initiated before an error stopped the loop. - **Charge:** **Actual completed item invocations**. - **Settlement state:** `Proportionally settled`. - **Real-world scenario:** In a 100-item loop, 45 items successfully run before an external rate limit (429) halts the run → 45 credits settled. **Outcome: Allowance Exhausted · 0 Credits (Free)** If your monthly balance reaches 100%, the step is not admitted to the execution queue. It halts safely with `out_of_credits` without consuming any credits. - **Charge:** **0 credits (Free)**. - **Settlement state:** `Halted without charge`. - **Real-world scenario:** A webhook fires when monthly credits are depleted → the step halts safely with 0 charge. --- ### Loops and batch processing Workflows that iterate over collections of items meter each item pass individually: **Single-step loop execution:** - The step reserves credits equal to the total item count. - Upon completion, credits settle based on the actual items processed. - **Worked example:** A Slack step sending messages to 150 customer rows uses **150 Step credits**. **Multi-step loop body execution:** - Each step inside the loop body meters its executions per iteration. - **Worked example:** A loop body with 3 steps (Enrich Data → AI Prompt → Update CRM) running over 20 items consumes up to **60 Step credits** (3 steps × 20 passes), plus any tokens used by the AI step. **Modular child workflow execution:** - The parent step consumes **1 Step credit** to initiate the child execution. - The child workflow executes independently, with its internal steps metered normally. - Returning data back to the parent workflow incurs no additional charge. > **Batch admission protection:** Before starting a large batch, Glow verifies > that your workspace has sufficient remaining credits for the full list. If a > batch exceeds your available monthly balance, the step pauses safely rather > than partially executing and draining your account. --- ## 2. Glow AI Tokens Hosted AI features—including **AI Prompt**, **AI Agent**, **AI Data Transform**, and **Workflow Assistant**—draw from your workspace's **Glow AI tokens** balance. ```text Total Billable AI Tokens = Input Tokens + Generated Output Tokens + Reasoning Tokens ``` - **Input tokens:** Prompt instructions, schema definitions, and context documents sent to the model. - **Output tokens:** The generated response, JSON object, or text produced by the model. - **Reasoning tokens:** Internal step-by-step thinking tokens generated by advanced reasoning models. - **Autonomous agent loops:** In multi-step agent executions, every reasoning turn and tool-decision call meters its individual token consumption. ### Hosted Glow AI vs. Custom Provider Keys **Managed Glow AI:** - **API Keys:** None required; fully managed by Glow. - **Metering:** Token usage deducts directly from your workspace's **Glow AI tokens** allowance. - **Step Credits:** Consumes standard Step credits for canvas execution + tokens for model generation. **Third-Party API Keys (OpenAI, Anthropic, etc.):** - **API Keys:** You provide your own external API key in the step configuration. - **Metering:** Consumes **1 standard Step credit** in Glow. - **Token Costs:** Token consumption is billed directly to your third-party account by the model provider (0 Glow AI tokens deducted). --- ## 3. Retained File Storage Workspaces store uploaded attachments, CSV datasets, generated PDFs, and integration assets in **Retained file storage**. | Model Attribute | Policy | Operational Behavior | | :-------------------- | :------------------------- | :------------------------------------------------------------------------ | | **Standing Quota** | Measured in Gigabytes (GB) | Continuous workspace storage allocation. | | **Reset Schedule** | Never resets | Retained capacity persists across billing cycles. | | **Quota Checks** | Pre-upload verification | Validates available disk quota before storing files. | | **Capacity Handling** | Fail-safe retention | Existing files remain accessible; new uploads pause until space is freed. | - **Standing Capacity:** Unlike Step credits and AI tokens, file storage represents physical cloud disk volume and does not reset each month. - **Persistent Files:** Stored files remain permanently available until deleted by workspace team members. - **Upload Quota Checks:** Before committing a new file upload or file-generation step, the system verifies that the resulting total size fits within your allocated storage. - **Over-Capacity Behavior:** If storage reaches capacity, existing files remain safe, readable, and downloadable. New uploads pause until unused files are deleted or storage capacity is increased. --- ## Real-world calculation examples | Workflow Scenario | Configuration | Monthly Runs | Estimated Resource Consumption | | :------------------------------ | :---------------------------------------------- | :----------------- | :--------------------------------------------------------------------- | | **Lead Routing & CRM Alert** | 4 steps (Webhook → Filter → HubSpot → Slack) | 5,000 leads / mo | **20,000 Step credits**0 AI tokens · < 0.1 GB storage | | **AI Customer Support Triage** | 3 steps (Webhook → AI Prompt → Zendesk Reply) | 2,500 tickets / mo | **7,500 Step credits**~3.5M Glow AI tokens · < 0.5 GB storage | | **Daily CSV Report Processing** | Scheduler → Fetch CSV (500 rows) → Loop 2 steps | 30 days / mo | **30,060 Step credits**0 AI tokens · ~2.0 GB storage | ## What's Next? - 👉 **[Purchasing & Changing Amounts →](/manage/billing/subscription-plans)**: Select tailored resource amounts for your team. - **[Invoices & Payment Methods](/manage/billing/invoices-and-payments)**: Download past invoices, receipts, and manage billing contacts. - **[Usage Controls & Recovery](/manage/billing/usage-controls-and-recovery)**: Configure automated alerts, safeguards, and recovery workflows.