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feat(backends): add retry/backoff controls for external CLI execution

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This commit is contained in:
William Valentin
2026-02-17 09:49:06 -08:00
parent 1f3d35726b
commit 4400bdfcc9
5 changed files with 64 additions and 8 deletions
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README.md
+2
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@@ -330,6 +330,8 @@ backends:
gemini: { enabled: false, path: /usr/local/bin/gemini, args: [], timeout_ms: 120000 }
```
Each external backend also supports `retries` and `retry_delay_ms` for transient CLI failures.
When `args` is non-empty:
- use `{prompt}` in an argument to inject the full generated prompt directly into argv.
- if `{prompt}` is not present, Flynn writes the prompt to stdin.
src/backends/external.test.ts
+34
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@@ -15,6 +15,19 @@ vi.mock('child_process', () => ({
const mockExecFile = vi.mocked(execFile);
function makeFailChild(stderrText = 'failed'): FakeChild {
const child = new EventEmitter() as FakeChild;
child.stdout = new EventEmitter();
child.stderr = new EventEmitter();
child.stdin = { end: vi.fn() };
child.kill = vi.fn();
setImmediate(() => {
child.stderr.emit('data', Buffer.from(stderrText));
child.emit('close', 1);
});
return child;
}
describe('ExternalCliBackend', () => {
beforeEach(() => {
vi.clearAllMocks();
@@ -104,4 +117,25 @@ describe('ExternalCliBackend', () => {
expect(opencode.name).toBe('opencode');
expect(gemini.name).toBe('gemini');
});
it('retries failed backend calls when retries are configured', async () => {
spawnMock
.mockImplementationOnce(() => makeFailChild('transient'))
.mockImplementationOnce(() => makeChild('recovered'));
const backend = new ExternalCliBackend({
name: 'codex',
command: 'codex',
retries: 1,
retryDelayMs: 0,
});
const result = await backend.process({
systemPrompt: 'sys',
history: [],
message: 'retry me',
});
expect(result).toBe('recovered');
expect(spawnMock).toHaveBeenCalledTimes(2);
});
});
src/config/schema.test.ts
+14 -2
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@@ -208,15 +208,23 @@ describe('configSchema — backends', () => {
expect(result.backends.claude_code.enabled).toBe(false);
expect(result.backends.claude_code.args).toEqual([]);
expect(result.backends.claude_code.timeout_ms).toBe(120000);
expect(result.backends.claude_code.retries).toBe(0);
expect(result.backends.claude_code.retry_delay_ms).toBe(300);
expect(result.backends.opencode.enabled).toBe(false);
expect(result.backends.opencode.args).toEqual([]);
expect(result.backends.opencode.timeout_ms).toBe(120000);
expect(result.backends.opencode.retries).toBe(0);
expect(result.backends.opencode.retry_delay_ms).toBe(300);
expect(result.backends.codex.enabled).toBe(false);
expect(result.backends.codex.args).toEqual([]);
expect(result.backends.codex.timeout_ms).toBe(120000);
expect(result.backends.codex.retries).toBe(0);
expect(result.backends.codex.retry_delay_ms).toBe(300);
expect(result.backends.gemini.enabled).toBe(false);
expect(result.backends.gemini.args).toEqual([]);
expect(result.backends.gemini.timeout_ms).toBe(120000);
expect(result.backends.gemini.retries).toBe(0);
expect(result.backends.gemini.retry_delay_ms).toBe(300);
});
it('accepts explicit external backend configs', () => {
@@ -225,8 +233,8 @@ describe('configSchema — backends', () => {
backends: {
default: 'codex',
native: { enabled: false },
codex: { enabled: true, path: '/usr/local/bin/codex', args: ['run'], timeout_ms: 300000 },
gemini: { enabled: true, path: '/usr/local/bin/gemini', args: ['chat'], timeout_ms: 60000 },
codex: { enabled: true, path: '/usr/local/bin/codex', args: ['run'], timeout_ms: 300000, retries: 2, retry_delay_ms: 1000 },
gemini: { enabled: true, path: '/usr/local/bin/gemini', args: ['chat'], timeout_ms: 60000, retries: 1, retry_delay_ms: 500 },
},
});
expect(result.backends.default).toBe('codex');
@@ -235,10 +243,14 @@ describe('configSchema — backends', () => {
expect(result.backends.codex.path).toBe('/usr/local/bin/codex');
expect(result.backends.codex.args).toEqual(['run']);
expect(result.backends.codex.timeout_ms).toBe(300000);
expect(result.backends.codex.retries).toBe(2);
expect(result.backends.codex.retry_delay_ms).toBe(1000);
expect(result.backends.gemini.enabled).toBe(true);
expect(result.backends.gemini.path).toBe('/usr/local/bin/gemini');
expect(result.backends.gemini.args).toEqual(['chat']);
expect(result.backends.gemini.timeout_ms).toBe(60000);
expect(result.backends.gemini.retries).toBe(1);
expect(result.backends.gemini.retry_delay_ms).toBe(500);
});
});
src/config/schema.ts
+8
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@@ -176,24 +176,32 @@ const backendsSchema = z.object({
path: z.string().optional(),
args: z.array(z.string()).default([]),
timeout_ms: z.number().min(1_000).max(600_000).default(120_000),
retries: z.number().min(0).max(5).default(0),
retry_delay_ms: z.number().min(0).max(30_000).default(300),
}).default({ enabled: false }),
opencode: z.object({
enabled: z.boolean().default(false),
path: z.string().optional(),
args: z.array(z.string()).default([]),
timeout_ms: z.number().min(1_000).max(600_000).default(120_000),
retries: z.number().min(0).max(5).default(0),
retry_delay_ms: z.number().min(0).max(30_000).default(300),
}).default({ enabled: false }),
codex: z.object({
enabled: z.boolean().default(false),
path: z.string().optional(),
args: z.array(z.string()).default([]),
timeout_ms: z.number().min(1_000).max(600_000).default(120_000),
retries: z.number().min(0).max(5).default(0),
retry_delay_ms: z.number().min(0).max(30_000).default(300),
}).default({ enabled: false }),
gemini: z.object({
enabled: z.boolean().default(false),
path: z.string().optional(),
args: z.array(z.string()).default([]),
timeout_ms: z.number().min(1_000).max(600_000).default(120_000),
retries: z.number().min(0).max(5).default(0),
retry_delay_ms: z.number().min(0).max(30_000).default(300),
}).default({ enabled: false }),
codex: z.object({
enabled: z.boolean().default(false),
src/daemon/index.test.ts
+6 -6
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@@ -19,7 +19,7 @@ describe('createConfiguredExternalBackend', () => {
...base,
backends: {
...base.backends,
codex: { enabled: true, path: '/usr/bin/codex', args: [], timeout_ms: 120000 },
codex: { enabled: true, path: '/usr/bin/codex', args: [], timeout_ms: 120000, retries: 0, retry_delay_ms: 300 },
},
};
const backend = createConfiguredExternalBackend(cfg);
@@ -31,7 +31,7 @@ describe('createConfiguredExternalBackend', () => {
...base,
backends: {
...base.backends,
gemini: { enabled: true, path: '/usr/bin/gemini', args: [], timeout_ms: 120000 },
gemini: { enabled: true, path: '/usr/bin/gemini', args: [], timeout_ms: 120000, retries: 0, retry_delay_ms: 300 },
},
};
const backend = createConfiguredExternalBackend(cfg);
@@ -43,8 +43,8 @@ describe('createConfiguredExternalBackend', () => {
...base,
backends: {
...base.backends,
codex: { enabled: true, path: '/usr/bin/codex', args: [], timeout_ms: 120000 },
gemini: { enabled: true, path: '/usr/bin/gemini', args: [], timeout_ms: 120000 },
codex: { enabled: true, path: '/usr/bin/codex', args: [], timeout_ms: 120000, retries: 0, retry_delay_ms: 300 },
gemini: { enabled: true, path: '/usr/bin/gemini', args: [], timeout_ms: 120000, retries: 0, retry_delay_ms: 300 },
},
};
const configured = createConfiguredExternalBackends(cfg);
@@ -59,8 +59,8 @@ describe('createConfiguredExternalBackend', () => {
backends: {
...base.backends,
default: 'gemini' as const,
codex: { enabled: true, path: '/usr/bin/codex', args: [], timeout_ms: 120000 },
gemini: { enabled: true, path: '/usr/bin/gemini', args: [], timeout_ms: 120000 },
codex: { enabled: true, path: '/usr/bin/codex', args: [], timeout_ms: 120000, retries: 0, retry_delay_ms: 300 },
gemini: { enabled: true, path: '/usr/bin/gemini', args: [], timeout_ms: 120000, retries: 0, retry_delay_ms: 300 },
},
};
const configured = createConfiguredExternalBackends(cfg);