# Flow HTTP Callout Action

> Call external HTTP APIs directly from Flow using HTTP Callout actions (no Apex), handling auth, schema, and errors. NOT for registering an OpenAPI spec as an External Service — use flow/flow-external-services. NOT for Apex callout logic and mock tests — use apex/callouts-and-http-integrations.

- Skill: `pranavnagrecha/flow-http-callout-action` (Agent Skill, multi-file: 7 files)
- Install (CLI): `npx skillmds add pranavnagrecha/flow-http-callout-action`
- Raw SKILL.md: https://api.skillmd.com/api/skills/pranavnagrecha/flow-http-callout-action/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: PranavNagrecha (https://skillmd.com/u/pranavnagrecha)
- Updated: 2026-09-08
- Page: https://skillmd.com/skills/pranavnagrecha/flow-http-callout-action

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# Flow HTTP Callout Action

Flow HTTP Callouts (GA) let admins call GET/POST/PATCH endpoints without Apex. You define the action against a Named Credential, supply a sample response for schema, and map inputs/outputs in flow variables. This skill covers auth, schema inference, pagination, and error handling.

## Adoption Signals

Low-volume admin-driven integrations (weather lookup, address verification, single-record enrichment). Not for high-volume or complex transactions.

- Prefer **<200 calls/day**; switch to Apex callouts above that threshold to escape per-Flow concurrency limits.
- Required when the integration must run inside a screen flow without an admin-coded Apex dependency.

## Recommended Workflow

1. Create a Named Credential for auth (JWT, OAuth, or API Key).
2. In Flow → New Action → HTTP Callout. Pick the NC, method, path.
3. Provide a sample request + sample response; Flow infers the schema.
4. Reference the action in your flow; map inputs and consume outputs.
5. Add fault path on the action → handle 4xx/5xx (e.g., message screen on error).

## Key Considerations

- Named Credential must be External Credential + Principal type — the old flavor doesn't work.
- Schema inference is rigid; complex nested JSON may require Apex wrapper.
- No automatic pagination handling — you loop.
- Transaction timeout applies to callouts inside record-triggered flows.

## Worked Examples (see `references/examples.md`)

- *Address verification* — Lead capture
- *Weather lookup* — Field service dispatch

## Common Gotchas (see `references/gotchas.md`)

- **NC version mismatch** — Callout fails auth.
- **Complex JSON** — Schema infer misses nested fields.
- **No fault path** — Flow fails to user.

## Top LLM Anti-Patterns (full list in `references/llm-anti-patterns.md`)

- Apex for trivial GET
- Legacy Named Credential
- No fault path

## Official Sources Used

- Flow Builder Guide — https://help.salesforce.com/s/articleView?id=sf.flow.htm
- Flow Best Practices — https://help.salesforce.com/s/articleView?id=sf.flow_best_practices.htm
- Reactive Screens — https://help.salesforce.com/s/articleView?id=sf.flow_ref_elements_screen_reactive.htm
- Flow HTTP Callout Action — https://help.salesforce.com/s/articleView?id=sf.flow_concepts_callout.htm