207aab9d8d
A well-formed provider stream that ends with finish_reason stop and zero
content blocks previously became a successful empty assistant message: the
turn completed silently, and drivers like goal-session counted the no-op
round. Both adapters now map that degenerate completion to a finish
{kind:'error'} with the new canonical EMPTY_RESPONSE code from dsh-llm, and
dsh-llm-retry adds the code to its default retryable set, so the existing
closed-step recovery path retries it and fails loud once the budget is
exhausted.
Covered by adapter unit tests, an llm-retry default-policy test, and a new
authored keyless ACP snapshot (empty-response-retry) with a deterministic
1 ms zero-jitter retry overlay.
2.9 KiB
@deepseek-ai/dsh-llm-retry
Function plugin that retries selected transient model-request failures on the agent loop's closed-step recovery seam. It does not wrap ctx.llm.stream(): every adapter call remains one provider attempt, and every retry opens a fresh numbered step.
The default policy permits two retries for EMPTY_RESPONSE, RATE_LIMIT, SERVER, TIMEOUT, and TRANSPORT, using bounded exponential backoff from 500 ms to 10 seconds with 10 percent jitter. EMPTY_RESPONSE is the adapters' classification of a degenerate provider completion (a terminal stop with zero content blocks); the attempt produced nothing durable, so repeating it is safe. Delay bounds must fit Node's supported timer range. A valid providerRetryAfterMs replaces local backoff when it is within the configured cap; an over-cap instruction delegates to the next recovery policy instead.
Before waiting, the plugin appends a non-surface llm/retry event with the failure and scheduled delay. Cancellation and plugin disposal abort the wait; disposal drains the plugin's active backoffs, and a callback captured before disposal fails closed if invoked afterward.
The separately published ./invariant companion checks that every retry record names the current open turn and its latest closed step, has a unique step record and increasing retry number, and carries a positive bounded retry budget and non-negative bounded timer delay. Full jitter may schedule zero milliseconds at its lower boundary.
- name: '@deepseek-ai/dsh-llm-retry'
config:
maxTransientRetries: 2
initialDelayMs: 500
maxDelayMs: 10000
jitterRatio: 0.1
retryableCodes: [EMPTY_RESPONSE, RATE_LIMIT, SERVER, TIMEOUT, TRANSPORT]
Model Experience
Transient request recovery
What the model sees
No retry event, delay, or failure prose is model-visible. After a retry, the next numbered step reconstructs the same explicit provider/model request from durable session history; failed chunks never enter derived messages.
Token effect
Each retry is a new provider request and may repeat input-token billing. The finite budget caps attempts; llm/retry itself contributes no tokens.
KV Cache effect
The reconstructed request preserves the prior prefix and is eligible for provider cache reuse under that provider's rules. The non-surface status event does not change cache identity.
Known Limitations and Deferred Work
- Agent steps are the only retry boundary — direct
ctx.llm.stream()consumers remain single-attempt because a raw stream cannot separate already-emitted chunks durably. - Finite plugin budgets add — this policy counts only configured transient codes; context-overflow compaction counts only its own code. A future policy with overlapping codes must document and test registration-order behavior.
llm/retryrecords scheduling, not completion — later step and turn events establish success, exhaustion, or cancellation.