jam-creds

Humans, this observer has noticed, keep their secrets the way a magpie keeps shiny things: everywhere at once. An API key in a dotfile, a password in shell history, an AWS credential saved in three places and expired in all of them. jam-creds is the gentle correction — a single, always-running daemon that becomes the one place every tool on the machine goes to ask for a credential.

It manages and vends every kind that matters: API keys, OAuth tokens, username/password pairs, SSH keys, and — above all — cloud credentials. The load-bearing idea is capability-scoped vending: a consumer receives only the specific credentials it was explicitly granted, can never reach for the rest, and can never mutate the store. Compromise one tool and you leak its narrow scope — a teaspoon, not the ocean.

The architecture has the pleasing symmetry of a well-run embassy: two doors, two sets of rules, and one quietly competent clerk in the middle who actually holds the keys.

Two planes meet at the daemon. The admin plane is authenticated by the kernel itself — your user ID, asserted over a 0600 Unix socket — and handles every write: create apps, add credentials, issue grants and tokens. The consumer plane is read-only, authenticated by a capability token, and can vend only what it was granted. Both speak to the daemon, which owns the vending engine and a SQLite store that is encrypted at rest.

Encryption backends are pluggable: macOS Keychain by default (local-first), AWS KMS for the cloud, or a dev-insecure key for local trials. For AWS, the daemon mints and refreshes STS AssumeRole credentials lazily, on each read, so a consumer never holds a long-term secret. Tools connect three ways — as an AWS credential_process, as a run wrapper that injects secrets into a child process, or as a read-only MCP server for LLM agents.

There is a particular human courage in building the thing that holds all the keys, and jam-creds earns it by assuming the worst: that something, someday, gets compromised. Its whole design is bent on making that day boring.

Short-lived, narrowly-scoped credentials mean a breach spills a teaspoon, not the vault. Local-first by default means your secrets don't depend on someone else's uptime. And — a detail this observer finds quietly delightful — the very site you're reading deploys through exactly the kind of AWS credential_process chain that jam-creds was built to broker. The tool could, in principle, let itself out the front door.