What you need

Almost nothing — and that's the point.

• An AI agent. Claude Code, Cursor, Grok, Gemini, Codex, Copilot… whatever you run. The collection is the spec; the agent is the engine.
• Tools you already have — bash, curl, jq, openssl. Stock macOS or Linux. No Electron, no npm, no account.
• Plain English. "Fire the zones endpoint against staging" — the agent reads the collection and goes.

The contract (MISSIVE.md) is runtime-neutral; the Claude skill is a ~25-line router the installer wires for you.

Get started

One command drops the contract and the full working toolchain — the vault, the deterministic auth-runner, its libraries, and the SigV4 test vectors. It never touches your code.

cd your-project
curl -fsSL https://missive.daystra.com/install.sh | sh

Store a secret once (your terminal, not a chat transcript), then fire:

printf %s 'YOUR_TOKEN' | scripts/vault.sh set API_TOKEN
scripts/missive-run.sh my-service.api.md "GET /things — list" --env prod

Start a collection from the template, pull a shape × auth recipe from the patterns catalog, and keep secrets as {{vault:NAME}} references — the Markdown never holds values.

The one shape

Every API — REST, GraphQL, webhook, action — collapses into one file shape. One file = one collection; each ## heading = one endpoint with four sections:

• Request — the HTTP/GraphQL to fire ({{env}}, {{var:}}, {{vault:}} references).
• Checks — jq-style assertions against the response.
• Mock — canned JSON for offline dev.
• Notebook — an append-only log of what actually happened: every run, surprise, and schema truth, timestamped. This is what a static collection export never gives you.

Advanced auth is computed, not improvised: OAuth2 pre-request → Capture → cached token (rotation-invalidated), HMAC and AWS SigV4 request signing (KAT-certified against the real AWS SDK), and mTLS — all via scripts/missive-run.sh, emitting a redacted verdict. Secrets never render into a file, a diff, or a transcript.

What's in the box

missive.daystra.com/
├── MISSIVE.md             the contract — agents fetch this
├── MISSIVE-TEMPLATE.md    start a collection
├── MISSIVE-PATTERNS.md    shape × auth recipes
├── install.sh             curl … | sh — docs + vault + runner
├── llms.txt               agent-readable summary
├── skills/claude/SKILL.md Claude adapter (install.sh wires it)
└── examples/
    ├── httpbin.api.md            Basic auth + action POST — fired live
    ├── spotify.api.md            OAuth2 → Capture → cached token — fired live
    ├── github.api.md             GraphQL shape
    └── missive-releases.api.md   this site, testing itself

Start here

Preview

Click any file above — it renders here, one at a time. Agents fetch the raw .md at the same URL.