- An execution environment — how containers start, stay warm, scale, and get a request budget. This is the architecture your code runs inside.
- An entrypoint contract — which file the platform runs and how a request reaches your code, per language.
- Bindings — declared connections to platform resources: the Telnyx API, secrets, KV, and object storage, with credentials injected for you so nothing sensitive lives in your code.
Real containers
Because a function is a real container:- Native runtimes — Node.js, Go, Python, and Java (Quarkus) run as themselves. No fetch-only sandbox, no restricted language subset.
- Any dependency that installs — npm packages, Go modules, PyPI packages, Maven artifacts.
- POSIX environment — environment variables, plus file I/O in the working directory and
/tmp. The root filesystem is read-only and writes are ephemeral — they don’t survive the container being recycled, so persist real data in KV or a bucket. - Outbound network — HTTP clients, TCP sockets, DNS resolution.
The entrypoint contract
HTTP is the only trigger. What “handling a request” means differs by language:
The exact per-language contract — files, signatures, health probes, bodies, the request budget — is specified in HTTP handler.
Bindings
A function reaches platform resources — the Telnyx API, secrets, KV, and object storage — through bindings you declare in the project manifest. The platform injects the credential, so no keys or tokens appear in your code. How you reach a binding depends on the language:- TypeScript gets a typed handle for each declared binding, resolved at runtime.
- Go, Python, and Java reach the same resources through injected environment variables (the Telnyx API key, each secret) and REST.
In this section
Execution model
How your code runs: cold starts, warm reuse, scaling, the request budget, and where state lives.
HTTP handler
The per-language entrypoint contract — files, signatures, health probes.
Bindings
Reach platform resources — Telnyx API, secrets, KV, object storage — from any language.