API Key Management in Cycles

Every request to the Cycles server requires an API key. This page explains how API keys work, how to create and manage them, and how they relate to tenant isolation.

How API keys work

The Cycles server authenticates requests using the X-Cycles-API-Key header. Each API key is associated with exactly one tenant.

When a request arrives:

The server extracts the X-Cycles-API-Key header
Validates the key exists and is active
Derives the effective tenant from the key
Verifies that subject.tenant in the request body matches the key's tenant
If any check fails, returns 401 UNAUTHORIZED or 403 FORBIDDEN

This ensures strict tenant isolation — an API key for tenant A cannot create reservations or query balances for tenant B.

Key states

An API key can be in one of three states:

State	Meaning
`ACTIVE`	Key is valid and can be used for requests
`REVOKED`	Key has been manually disabled
`EXPIRED`	Key has passed its expiration date

Only ACTIVE keys are accepted. Requests with REVOKED or EXPIRED keys receive 401 UNAUTHORIZED.

Creating API keys

API keys are managed through the Cycles Admin interface:

bash

# Create a new API key for a tenant
curl -X POST http://localhost:7979/v1/admin/api-keys \
  -H "Content-Type: application/json" \
  -H "X-Admin-API-Key: $ADMIN_API_KEY" \
  -d '{
    "tenant_id": "acme",
    "name": "production-chatbot",
    "description": "Production chatbot key",
    "permissions": ["reservations:create", "reservations:commit", "reservations:release", "balances:read"]
  }'

Available permissions (27 total)

Tenant-scoped permissions (used with X-Cycles-API-Key for runtime and tenant operations):

Permission	Grants	Default
`reservations:create`	Create new reservations	Yes
`reservations:commit`	Commit existing reservations	Yes
`reservations:release`	Release existing reservations	Yes
`reservations:extend`	Extend reservation TTL	Yes
`reservations:list`	List reservations	Yes
`balances:read`	Query balance information	Yes
`webhooks:write`	Create, update, delete tenant webhooks at `/v1/webhooks`	No
`webhooks:read`	List tenant webhooks and delivery history	No
`events:read`	Query tenant event stream at `/v1/events`	No

Tenant budget/policy permissions (v0.1.25.6+):

Permission	Grants	Default?
`budgets:read`	List and read own tenant budgets	Yes
`budgets:write`	Create and fund own tenant budgets	Yes
`policies:read`	List and read own tenant policies	Yes
`policies:write`	Create and update own tenant policies	Yes

Admin wildcard permissions (used with X-Cycles-API-Key for admin operations):

Permission	Grants
`admin:read`	Satisfies any `*:read` permission (budgets:read, policies:read, webhooks:read, events:read, etc.)
`admin:write`	Satisfies any `*:write` permission (budgets:write, policies:write, webhooks:write, etc.). Does NOT grant read access — use both `admin:read` and `admin:write` for full access.

Wildcard behavior (v0.1.25.7+)

admin:write acts as a server-level wildcard — it satisfies any *:write permission requirement. This means pre-v0.1.25.6 keys with admin:write continue to work without migration even after granular permissions were introduced. admin:read does NOT satisfy *:write.

Admin granular permissions (v0.1.25+ — finer-grained alternative to admin wildcards):

Permission	Grants
`admin:tenants:read`	Read tenant details
`admin:tenants:write`	Create and update tenants
`admin:budgets:read`	List and read budgets
`admin:budgets:write`	Create, fund, and update budgets
`admin:policies:read`	List and read policies
`admin:policies:write`	Create and update policies
`admin:apikeys:read`	List API keys
`admin:apikeys:write`	Create and revoke API keys
`admin:webhooks:read`	List admin webhook subscriptions and deliveries
`admin:webhooks:write`	Create, update, delete, test, and replay admin webhooks
`admin:events:read`	Query admin event stream
`admin:audit:read`	Query audit logs

Defaults: When no permissions are specified at key creation, the key receives 10 default permissions: the 6 runtime permissions (reservations:create, reservations:commit, reservations:release, reservations:extend, reservations:list, balances:read) plus budgets:read, budgets:write, policies:read, policies:write. Webhook, event, and admin permissions must be explicitly requested.

A typical runtime key needs only the 6 defaults. Add budgets:write and budgets:read if tenants manage their own budgets. Add webhooks:write and webhooks:read for webhook subscriptions. Add admin:read/admin:write (or granular equivalents) only if the key is used for cross-tenant admin operations via the admin server (port 7979).

Admin permissions on tenant keys (v0.1.25.7)

admin:read and admin:write are accepted on tenant keys for backward compatibility, but SHOULD NOT be assigned to new tenant keys. Use the specific permissions (budgets:write, policies:read, etc.) instead. The admin key (X-Admin-API-Key) is server-configured and is not provisioned through the API key creation endpoint.

For the full endpoint-to-header-to-permission mapping, see the Architecture Overview — Authentication.

Response:

json

{
  "key_id": "key_abc123...",
  "key_secret": "cyc_live_abc123...",
  "key_prefix": "cyc_live_abc12",
  "tenant_id": "acme",
  "permissions": ["reservations:create", "reservations:commit", "reservations:release", "balances:read"],
  "created_at": "2026-03-01T00:00:00Z",
  "expires_at": "2026-05-30T00:00:00Z"
}

Store the API key securely. It is shown only once at creation time.

Using API keys

In the Python client

Configure the key via CyclesConfig:

python

import os
from runcycles import CyclesConfig

config = CyclesConfig(
    base_url="http://localhost:7878",
    api_key=os.environ["CYCLES_API_KEY"],
    tenant="acme",
)

Or from environment variables:

bash

export CYCLES_BASE_URL=http://localhost:7878
export CYCLES_API_KEY=cyc_live_abc123...
export CYCLES_TENANT=acme

python

config = CyclesConfig.from_env()

In the Spring Boot Starter

Configure the key in your project's application.yml:

yaml

cycles:
  api-key: ${CYCLES_API_KEY}
  base-url: http://localhost:7878
  tenant: acme

Use an environment variable rather than hardcoding the key.

In direct HTTP calls

Pass the key in the X-Cycles-API-Key header:

bash

curl -X POST http://localhost:7878/v1/reservations \
  -H "Content-Type: application/json" \
  -H "X-Cycles-API-Key: cyc_live_abc123..." \
  -d '{ ... }'

Listing API keys

GET /v1/admin/api-keys lists keys. By default (tenant-scoped with X-Cycles-API-Key), the server returns keys for the authenticated tenant only. With X-Admin-API-Key you can list across all tenants by omitting the tenant_id query parameter (v0.1.25.22+). Cross-tenant results paginate with a composite (tenant_id, key_id) cursor.

bash

# Cross-tenant — all keys, sorted by last-used
curl -G "http://localhost:7979/v1/admin/api-keys" \
  -H "X-Admin-API-Key: $ADMIN_KEY" \
  --data-urlencode "sort_by=last_used_at_ms" \
  --data-urlencode "sort_dir=desc" \
  --data-urlencode "limit=50" | jq .

# Tenant-scoped
curl -G "http://localhost:7979/v1/admin/api-keys?tenant_id=acme" \
  -H "X-Admin-API-Key: $ADMIN_KEY" | jq .

search (v0.1.25.25+) does a case-insensitive match over key_id, name, and description. See Searching and Sorting Admin List Endpoints for the full parameter vocabulary.

Revoking API keys

Revoke from the dashboard

Key revocation is also a one-click action on the API Keys page in the Cycles Admin Dashboard — typically faster than crafting a curl when responding to a leaked-key incident. Revocation is irreversible; the dashboard surfaces a confirmation step.

Revoke a key to immediately block all requests using it:

bash

curl -X DELETE http://localhost:7979/v1/admin/api-keys/key_abc123 \
  -H "X-Admin-API-Key: $ADMIN_API_KEY"

Revocation is immediate. Any in-flight requests using the revoked key will fail on their next call to the Cycles server. Active reservations created with the revoked key remain valid until they expire or are committed/released.

Revocation, not deletion

The DELETE endpoint performs a status transition (ACTIVE → REVOKED), not a hard delete. The key record is retained so that audit logs referencing the key remain resolvable. This is consistent with the lifecycle model used across Cycles — see the equivalent notes on tenant closure and budget decommissioning.

Key rotation

To rotate an API key without downtime:

Create a new key for the same tenant
Update your application configuration to use the new key
Deploy the configuration change
Verify traffic is flowing with the new key
Revoke the old key

Because both keys are valid during the transition, there is no interruption.

Tenant isolation

API keys are the primary mechanism for tenant isolation in Cycles.

Enforced behaviors:

A key for tenant A can only create reservations where subject.tenant = "A" (or where tenant is omitted, in which case the server uses the key's tenant)
A key for tenant A cannot commit, release, or extend reservations owned by tenant B
A key for tenant A cannot query balances for tenant B
A key for tenant A cannot list reservations belonging to tenant B

If the tenant is omitted from the Subject, the server automatically sets it to the key's associated tenant. This is the recommended approach — configure the tenant at the key level and let the server enforce it.

Best practices

One key per environment

Use separate API keys for production, staging, and development, even within the same tenant. This makes it easy to revoke a single environment's access without affecting others.

Use environment variables

Never hardcode API keys in source code:

yaml

# Good
cycles:
  api-key: ${CYCLES_API_KEY}

# Bad
cycles:
  api-key: cyc_live_abc123...

Minimal key scope

If you operate multiple tenants, issue one key per tenant. Do not share keys across tenants.

Monitor key usage

Track which keys are making requests. If a key is compromised, revoke it immediately and issue a replacement.

Error responses

Error	HTTP	When
`UNAUTHORIZED`	401	Missing `X-Cycles-API-Key` header, or key is invalid/revoked/expired
`FORBIDDEN`	403	Key is valid but `subject.tenant` does not match the key's tenant
`INSUFFICIENT_PERMISSIONS`	403	Key is valid but lacks the required permission for the endpoint (e.g., calling a budget endpoint without `admin:write`)

Next steps

Tenant Creation and Management — create and manage the tenants that API keys belong to
Authentication and Tenancy — deeper dive into the auth model
Self-Hosting the Cycles Server — deploy your own instance
Architecture Overview — how authentication fits into the system

API Key Management in Cycles ​

How API keys work ​

Key states ​

Creating API keys ​

Available permissions (27 total) ​

Using API keys ​

In the Python client ​

In the Spring Boot Starter ​

In direct HTTP calls ​

Listing API keys ​

Revoking API keys ​

Key rotation ​

Tenant isolation ​

Best practices ​

One key per environment ​

Use environment variables ​

Minimal key scope ​

Monitor key usage ​

Error responses ​

Next steps ​

API Key Management in Cycles

How API keys work

Key states

Creating API keys

Available permissions (27 total)

Using API keys

In the Python client

In the Spring Boot Starter

In direct HTTP calls

Listing API keys

Revoking API keys

Key rotation

Tenant isolation

Best practices

One key per environment

Use environment variables

Minimal key scope

Monitor key usage

Error responses

Next steps