Data

Tools

Indexes

Applications

Experiments

Awesome

An open API service indexing awesome lists of open source software.

https://github.com/cjohnsto-nz/missio

A lightweight, OpenCollection compatible REST API client for VS Code.
https://github.com/cjohnsto-nz/missio

apiclient opencollection restclient vscode-extension

Last synced: 4 months ago
JSON representation

A lightweight, OpenCollection compatible REST API client for VS Code.

Awesome Lists containing this project

README 

          
# Missio REST Client



A lightweight, [OpenCollection](https://www.opencollection.com) compatible REST API client for VS Code.



Missio uses the OpenCollection standard, which is file based (and AI friendly). Collaboration is supported via Git and external secret providers.



Missio Editor Screenshot



## Missio is a REST Client without an identity crisis



### What Missio Is:

- **A VSCode Extension**

- **A REST Client**

- **Local, Git Native**



### What Missio Is Not:

- **A Standalone IDE**

- **A SAAS Platform**

- **Cloud Synced**

- **A Monthly Subscription**

- **Feature Complete vs Postman**



Missio aims to use VSCode functionality whereever possible.



Git integration, Workspaces, Commands, are all provided by VSCode. 



BYO Agentic Coding tools. 



### Please Note



Missio is still in alpha. Key missing features from Postman include:

- Scripting

- Websockets

- GraphQL



We aim to support these in the coming weeks.



## Features



### Collections & Requests

- **OpenCollection v1.0.0 compatible (partially at least)** — YAML-based collections, requests, folder, and environments

- **Auto-detect collections** — scans workspace for `collection.yml` / `workspace.yml`

- **Custom editors** — visual editors for requests, folders, and collections with native dirty indicators, Ctrl+S save, and undo/redo

- **Tree view sidebar** — browse collections, folders, and requests with inline actions

- **CodeLens** — send requests directly from YAML files

- **Import from Postman** — import Postman v2.0/v2.1 collections and environments

- **Import requests** — paste a cURL, wget, or raw HTTP request and import it directly into a collection



### Request Editor

- **Visual request builder** — method selector, URL bar, headers, query params, body (raw, form-encoded, multipart)

- **Send with Ctrl+Enter** — keyboard shortcut to send requests

- **Response viewer** — formatted body (JSON, XML, HTML) with syntax highlighting, word wrap, line numbers, headers, status, timing, and size

- **Response preview** — PDF and image responses render inline with an option to open in browser

- **Cancel requests** — cancel in-flight requests from the command palette or UI

- **Request timer** — live elapsed time display while a request is in progress, with the previous response dimmed until the new one arrives

- **Auto headers** — `Content-Type` and `Content-Length` are calculated automatically and shown as read-only (override by specifying your own)

- **Unresolved variable prompts** — if any `{{variables}}` remain unresolved after interpolation, a modal prompts you to fill them in before sending

- **Save examples** — save response snapshots and load them later



#### Large Response Handling



Very large responses (for example, large OData `$metadata` payloads) can be expensive to syntax-highlight and render in a webview.



Missio includes safeguards to keep the editor responsive:



- **Automatic virtualization** — large text responses are rendered using a windowed/virtualized view instead of creating DOM nodes for every line.

- **Header notice** — when virtualization is active, the response bar shows: `Large response was virtualized`.

- **Timing waterfall** — the timing tooltip includes virtualization phases such as `Split Lines` and `Virtualize`.



If you still need a hard escape hatch, you can disable response rendering entirely:



- **Setting**: `missio.disableResponseRendering` — when enabled, the response body is downloaded but not rendered (status/headers/timing/size still show).



### Variables & Environments

- **Environment management** — switch between dev/staging/prod with `{{variable}}` interpolation

- **Variable inheritance** — Collection > Folder > Environment (each layer overrides the previous)

- **Variable highlighting** — source-colored overlays on all input fields (URL, headers, params, body, auth)

- **Click-to-inspect** — click any `{{variable}}` to see its resolved value, source, and actions

- **Toggle resolved values** — `{{}}` button shows actual resolved values in-place across all fields

- **Autocomplete** — type `{{` to get variable suggestions with source labels

- **`.env` file support** — automatically loads `.env` files from collection directories



### Authentication

- **Auth types** — None, Bearer Token, Basic Auth, API Key, OAuth 2.0

- **Auth inheritance** — Request > Folder > Collection (first non-inherit wins)

- **OAuth 2.0** — client credentials, password, and authorization code (PKCE) flows with automatic token management

- **Token status display** — live token expiry countdown with Get Token / Refresh buttons in request, folder, and collection editors

- **Token caching** — tokens stored securely per collection, environment, and credentials

- **Refresh on 4xx** — helper button on 4xx responses to clear a stale OAuth token and retry



### Folder Defaults

- **Folder editor** — configure folder-level auth, headers, and variables via `folder.yml`

- **Folder inheritance** — folder defaults apply to all requests in the folder

- **New folders default to inherit** — auth set to `inherit` by default



### Collection Editor

- **Visual collection editor** — overview, auth, headers, variables, and environments tabs

- **Environment editor** — add, remove, rename environments with variable key-value editing

- **Collection-level defaults** — set default auth and headers for all requests

- **Validate collection** — right-click a collection to validate all files against the OpenCollection JSON schema



### Secret Providers

- **Azure Key Vault** — fetch secrets at runtime via `az cli` (no SDK required)

- **Collection-scoped config** — secret providers defined in `collection.yml`, fully portable

- **`$secret` syntax** — reference secrets with `{{$secret.providerName.secretName}}` in any field

- **Secret autocomplete** — type `{{$secret.` to get provider and secret name suggestions

- **On-demand reveal** — click a secret variable to see its source, then click "Reveal Value" to fetch and display it

- **Test connection** — verify vault access and RBAC from the collection editor's Secrets tab



## Secret Providers



Secret providers are configured per-collection in `collection.yml`. Secrets are resolved at runtime — no secret values are stored in files.



### Azure Key Vault



Prerequisites: `az login` and RBAC access (Key Vault Secrets User) on the vault.



Add a provider to your collection:



```yaml

config:

  secretProviders:

    - name: my-vault

      type: azure-keyvault

      namespace: my-vault

```



The namespace supports variables — useful for per-environment vaults:



```yaml

config:

  secretProviders:

    - name: kv

      type: azure-keyvault

      namespace: "{{vault_name}}"

```



For cross-subscription vaults, specify the subscription:



```yaml

config:

  secretProviders:

    - name: kv

      type: azure-keyvault

      namespace: "{{vault_name}}"

      subscription: "{{subscription_id}}"

```



Then reference secrets anywhere you'd use a variable:



```yaml

http:

  auth:

    type: bearer

    token: "{{$secret.my-vault.api-key}}"

```



Secrets are resolved at send time and during OAuth2 token acquisition. The collection editor's **Secrets** tab lets you test connections and see available secret names.



## Commands



| Command | Description |

|---------|-------------|

| `Missio: Send Request` | Execute the current request |

| `Missio: Select Active Environment` | Choose the active environment |

| `Missio: New Collection` | Scaffold a new collection |

| `Missio: Import Collection` | Import from Postman (v2.0/v2.1) |

| `Missio: Import Request` | Import a request from cURL, wget, or raw HTTP format |

| `Missio: Import Environment` | Import environment from Postman |

| `Missio: New Request` | Create a new request YAML file |

| `Missio: New Folder` | Create a new folder in a collection |

| `Missio: New Environment` | Add an environment to a collection |

| `Missio: Configure Collection` | Open the collection editor |

| `Missio: Configure Folder` | Open the folder editor |

| `Missio: Refresh Collections` | Re-scan the workspace |

| `Missio: Configure Secret Provider` | Set up secret providers in collection |

| `Missio: Validate Collection` | Validate collection files against the OpenCollection schema |

| `Missio: Cancel Request` | Cancel all in-flight requests |



## Keyboard Shortcuts



| Shortcut | Action |

|----------|--------|

| `Ctrl+Enter` | Send request (in request editor) |



## OpenCollection Spec



This extension implements the [OpenCollection v1.0.0 specification](https://spec.opencollection.com). All unknown/unsupported fields in YAML files are preserved on save (round-trip safe).



- Schema: `https://schema.opencollection.com/json/draft-07/opencollection/v1.0.0`

- Workspace schema: `https://schema.opencollection.com/json/draft-07/opencollection-workspace/v1.0.0`



## License



MIT