Comparison
Secure runtime for code-mode agents: Submilli vs Cloudflare Code Mode
Cloudflare Code Mode is a tool-use pattern for composing configured tools in generated code. Submilli is a secure runtime for code-mode agents that need semantic permissions.
A practical comparison
Product details are current as of November 3, 2026. Rows appear only where the cited public sources establish a comparison.
| Area | Submilli | Cloudflare Code Mode |
|---|---|---|
| What it is | A runtime for executing agent-written programs under explicit rules. | A tool-use pattern and package that lets a model write code to compose configured tools. |
| Isolation model | One WebAssembly sandbox for each program, with its own files and limits. | For the Dynamic Workers executor, V8 runs each Worker in a sandbox that cannot read memory outside itself; Cloudflare adds a process-level sandbox. |
| Access controls | Semantic permissions define allowed operations, resources, and argument values. | For Dynamic Workers, the integration chooses bindings and whether the Worker can reach the network. The loader can block, redirect, or inherit the parent’s network access. |
| Where it runs | Runtime: self-hosted. Hosted cloud: operated by Submilli. Enterprise: your cloud. | Dynamic Workers execute runtime-specified code on Cloudflare Workers. |
| Pricing | Hosted cloud: freemium, usage-based. Enterprise: From $5,000/year, including BYOC and forward-deployed engineers. | Dynamic Workers uses the Workers Paid plan; pricing is based on daily Dynamic Workers, requests, and CPU time. |
| Best fit | Code-mode agents that need permissions checked outside the model. | Composing configured tools with loops, branching, filtering, and result shaping in a Cloudflare Agents integration. |
Secure runtime for code-mode agents. Runtime is free, open source, and Apache-2.0. Hosted cloud is freemium and usage-based. Enterprise: From $5,000/year, including BYOC and forward-deployed engineers.
When to choose Cloudflare Code Mode
Choose Cloudflare Code Mode when you are building on Cloudflare Agents and want the model to compose configured tools in one generated-code execution.
When to choose Submilli
Choose Submilli when you need each covered operation checked against rules for the resource and arguments.
Runs are durable: after a restart they resume where they left off, without repeating finished steps.
Sources
Last checked .