Replay Mode v3.9.0

replay is local-first mode with upstream fallback.

⚠️ EXPERIMENTAL FEATURE: replay mode is part of the experimental upstream modes feature set and may change without notice.

Behavior

For each incoming request:

1. GripMock tries local stub matching.
2. If a local match is found, local response is returned.
3. If matcher returns NotFound, request is forwarded to upstream.

This applies to unary, server-stream, client-stream, and bidirectional stream methods.

Matching semantics

Fallback is based on real matcher result with full criteria:

• input / inputs
• headers
• session
• contains / matches
• options.times

No heuristic shortcut is used for fallback decisions.

URL schemes

• grpc+replay://host:port
• grpcs+replay://host:port

Query parameters

Parameter	Default	Description
timeout	5s	Timeout for upstream requests.
bearer	—	Bearer token to include in upstream requests.
serverName	—	Override TLS server name (SNI).
insecureSkipVerify	false	Skip upstream TLS certificate verification.
recordDelay	false	Record response latency as delay in captured stubs (for upstream misses).

Example

GRPC_PORT=4770 HTTP_PORT=4771 \
gripmock "grpcs+replay://orders.api.local:8443?serverName=orders.api.local"

Order Service example

You already have minimal stubs for critical flows (for example CreateOrder, GetOrder), but many methods are still uncovered.

Runtime effect:

• requests that match local stubs are served by GripMock;
• unmatched requests fallback to real Order Service.

This mode is intended for safe gradual migration.

When to choose replay

• You already have partial local stubs.
• You still need upstream reliability for uncovered paths.
• You want deterministic behavior for covered paths with incremental expansion.